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Bryan Cardella

Bryan Cardella

Nervous System Part I: Neurons

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Table of Contents

Section 1: Anatomy & Physiology
Introduction to Anatomy & Physiology

25m 34s

Intro
0:00
Anatomy vs. Physiology
0:06
Anatomy
0:17
Pericardium
0:24
Physiology
0:57
Organization of Matter
1:38
Atoms
1:49
Molecules
2:54
Macromolecules
3:28
Organelles
4:17
Cells
5:01
Tissues
5:58
Organs
7:15
Organ Systems
7:42
Organisms
8:26
Relative Positions
8:41
Anterior vs. Posterior
9:14
Ventral vs. Dorsal is the Same as Anterior vs. Posterior for Human Species
11:03
Superior vs. Inferior
11:52
Examples
12:13
Medial vs. Lateral
12:39
Examples
13:01
Proximal vs. Distal
13:36
Examples
13:53
Superficial Vs. Deep
14:57
Examples
15:17
Body Planes
16:07
Coronal (Frontal) Plane
16:38
Sagittal Plane
17:16
Transverse (Horizontal) Plane
17:52
Abdominopelvic Regions
18:37
4 Quadrants
19:07
Right Upper Quadrant
19:47
Left Upper Quadrant
19:57
Right Lower Quadrant
20:06
Left Lower Quadrant
20:16
9 Regions
21:09
Right Hypochondriac
21:33
Left Hypochondriac
22:20
Epicastric Region
22:39
Lumbar Regions: Right and Left Lumbar
22:59
Umbilical Region
23:32
Hypogastric (Pubic) Region
23:46
Right and Left Inguinal (Iliac) Region
24:10
Tissues

38m 25s

Intro
0:00
Tissue Overview
0:05
Epithelial Tissue
0:27
Connective Tissue
1:04
Muscle Tissue
1:20
Neural Tissue
1:49
Histology
2:01
Epithelial Tissue
2:25
Attached to a 'Basal Lamina'
2:42
Avascular
3:38
Consistently Damaged by Environmental Factors
4:43
Types of Epithelium
5:35
Cell Structure / Shape
5:40
Layers
5:46
Example
5:52
Simple Squamous Epithelium
6:39
Meant for Areas That Need a High Rate of Diffusion / Osmosis
6:50
Locations: Alveolar Walls, Capillary Walls
7:15
Stratified Squamous Epithelium
9:10
Meant for Areas That Deal with a Lot of Friction
9:20
Locations: Epidermis of Skin, Esophagus, Vagina
9:27
Histological Slide of Esophagus / Stomach Connection
10:46
Simple Columnar Epithelium
12:02
Meant for Absorption / Secretion Typically
12:09
Locations: Lining of the Stomach, Intestines
13:08
Stratified Columnar Epithelium
13:29
Meant for Protection
14:07
Locations: Epiglottis, Anus, Urethra
14:14
Pseudostratified Columnar Epithelium
14:46
Meant for Protection / Secretion
16:06
Locations: Lining of the Trachea / Bronchi
16:25
Simple Cuboidal Epithelium
16:51
Meant for Mainly Secretion / Absorption
16:56
Locations: Kidney Tubules, Thyroid Gland
17:14
Stratified Cubodial Epithelium
18:18
Meant for Protection, Secretion, Absorption
18:52
Locations: Lining of Sweat Glands
19:04
Transitional Epithelium
19:15
Meant for Stretching and Recoil
19:17
Locations: Urinary Bladder, Uterus
20:36
Glandular Epithelium
20:43
Merocrine
21:19
Apocrine
22:58
Holocrine
24:01
Connective Tissues
25:06
Most Abundant Tissue
25:11
Connect and Bind Together All the Organs
25:20
Connective Tissue Fibers
26:13
Collagen Fibers
26:30
Elastic Fibers
27:55
Reticular Fibers
29:58
Connective Tissue Cells
30:52
Fibroblasts
30:57
Macrophages
31:33
Mast Cells
32:49
Lymphocytes
34:42
Adipocytes
35:03
Melanocytes
36:08
Connective Tissue Examples
36:39
Adipose Tissue
36:50
Tendons and Ligaments
37:23
Blood
38:06
Cartilage
38:30
Bone
38:51
Muscle
39:09
Integumentary System (Skin)

51m 15s

Intro
0:00
Functions of the Skin
0:07
Protection
0:13
Absorption
0:43
Secretion
1:19
Heat Regulation
1:52
Aesthetics
2:21
Major Layers
3:50
Epidermis
3:59
Dermis
4:45
Subcutaneous Layer (Hypodermis)
5:36
The Epidermis
5:56
Most Superficial Layers of Skin
5:57
Epithelial
6:11
Cell Types
7:16
Cell Type: Melanocytes
7:26
Cell Type: Keratinocytes
9:39
Stratum Basale
10:54
Helps Form Finger Prints
11:11
Dermis
11:54
Middle Layers of the Skin
12:16
Blood Flow
12:20
Hair
13:59
Glands
15:41
Sebaceous Glands
15:46
Sweat Glands
16:32
Arrector Pili Muscles
19:18
Two Main Kinds of Hair: Vellus and Terminal
19:57
Nails
21:43
Cutaneous Receptors (Nerve Endings)
23:48
Subcutaneous Layer
25:00
Deepest Part of the Skin
25:01
Composed of Connective Tissue
25:04
Fat Storage
25:11
Blood Flow
25:43
Cuts and Healing
26:33
Step 1: Inflammation
26:54
Step 2: Migration
28:46
Step 3: Proliferation
30:39
Step 4: Maturation
31:50
Burns
32:44
1st Degree
33:50
2nd Degree
34:38
3rd Degree
35:18
4th Degree
36:27
Rule of Nines
36:49
Skin Conditions and Disorders
40:02
Scars
40:06
Moles
41:11
Freckles/ Birthmarks
41:48
Melanoma/ Carcinoma
42:44
Acne
45:23
Warts
47:16
Wrinkles
48:14
Psoriasis
49:12
Eczema/ Rosacea
49:41
Vitiligo
50:19
Skeletal System

19m 30s

Intro
0:00
Functions of Bones
0:04
Support
0:09
Storage
0:24
Production of Blood
1:01
Protection
1:12
Leverage
1:28
Bone Anatomy
1:43
Spongy Bone
2:02
Compact Bone
2:47
Epiphysis / Diaphysis
3:01
Periosteum
3:38
Articular Cartilage
3:59
Lacunae
4:23
Canaliculi
5:07
Matrix
5:53
Osteons
6:21
Central Canal
7:00
Medullary Cavity
7:21
Bone Cell Types
7:39
Osteocytes
7:44
Osteoblasts
8:12
Osteoclasts
8:18
Bone Movement in Relation to Levers
10:11
Fulcrum
10:26
Resistance
10:50
Force
11:01
Factors Affecting Bone Growth
11:24
Nutrition
11:28
Hormones
12:28
Exercise
13:19
Bone Marrow
13:58
Red Marrow
14:04
Yellow Marrow
14:46
Bone Conditions / Disorders
15:06
Fractures
15:09
Osteopenia
17:12
Osteoporosis
17:51
Osteochondrodysplasia
18:22
Rickets
18:43
Axial Skeleton

35m 2s

Intro
0:00
Axial Skeleton
0:05
Skull
0:21
Hyoid
0:25
Vertebral Column
0:29
Thoracic Cage
0:32
Skull
0:35
Cranium
0:42
Sphenoid
0:58
Ethmoid
1:12
Frontal Bone
1:32
Sinuses
1:39
Sutures
2:50
Parietal Bones
3:29
Sutures
3:30
Most Superior / Lateral Cranial Bones
3:50
Fontanelles
4:17
Temporal Bones
5:00
Zygomatic Process
5:14
External Auditory Meatus
5:43
Mastoid Process
6:07
Styloid Process
6:28
Mandibular Fossa
7:04
Carotid Canals
7:50
Occipital Bone
8:12
Foramen Magnum
8:30
Occipital Condyle
9:03
Jugular Foramina
9:35
Sphenoid Bone
10:11
Forms Part of the Inferior Portion of the Cranium
10:39
Connects Cranium to Facial Bones
10:51
Has a Pair of Sinuses
11:06
Sella Turcica
11:26
Optic Canals
12:02
Greater/ Lesser Wings
12:19
Superior View of Cranium Interior
12:33
Ethmoid Bone
13:09
Forms the Superior Portion of Nasal Cavity
13:16
Images Contain the Crista Galli, Nasal Conchae, Perpendicular Plate, and 2 Sinuses
13:54
Maxillae
15:29
Holds the Upper Teeth, Forms the Inferior Portion of the Orbit, and Make Up the Upper Jaw and Hard Palate
15:50
Palatine Bones
16:17
Nasal Cavity Bones
16:55
Nasal Bones
17:07
Vomer
17:43
Interior Nasal Conchae
18:01
Sagittal Cross Section Through the Skull
19:03
More Facial Bones
19:45
Zygomatic Bones
19:57
Lacrimal Bones
20:12
Mandible
20:58
Lower Jaw Bone
20:59
Mandibular Condyles
21:05
Hyoid Bone
21:39
Supports the Larynx
21:47
Does Not Articular with Any Other Bones
22:02
Vertebral Column
22:45
26 Bones
22:49
There Are Cartilage Pads Called 'Intervertebral Discs' Between Each Vertebra
23:00
Vertebral Curvatures
24:55
Cervical
25:00
Thoracic
25:02
Lumbar
25:05
Atlas
25:28
Axis
26:20
Pelvic
28:20
Vertebral Column Side View
28:33
Sacrum/ Coccyx
29:29
Sacrum Has 5 Pieces
30:20
Coccyx Usually Has 4 Pieces
30:43
Thoracic Cage
31:00
12 Pairs of Ribs
31:05
Sternum
31:30
Costal Cartilage
33:22
Appendicular Skeleton

13m 53s

Intro
0:00
Pectoral Girdle
0:05
Clavicles
0:25
Scapulae
1:06
Arms
2:47
Humerus
2:50
Radius
3:56
Ulna
4:11
Carpals
4:57
Metacarpals
5:48
Phalanges
6:09
Pelvic Girdle
7:51
Coxal Bones / Coxae
7:57
Ilium
8:09
Ischium
8:16
Pubis
8:21
Male vs. Female
9:24
Legs
10:05
Femer
10:11
Patella
11:14
Tibia
11:34
Fibula
11:52
Tarsals
12:24
Metatarsals
13:03
Phalanges
13:21
Articulations (Joints)

26m 37s

Intro
0:00
Types of Joints
0:06
Synarthrosis
0:16
Amphiarthrosis
0:44
Synovial (Diarthrosis)
0:54
Kinds of Immovable Joints
1:09
Sutures
1:15
Gomphosis
2:17
Synchondrosis
2:44
Synostosis
4:59
Types of Amphiarthroses
5:31
Syndesmosis
5:36
Symphysis
6:07
Synovial Joint Anatomy
6:49
Articular Cartilage
7:04
Joint Capsule
7:49
Synovial Membrane
8:27
Bursae
8:48
Spongy / Compact Bone
9:28
Periosteum
10:12
Synovial Joint Movements
10:34
Flexion / Extension
10:41
Abduction / Adduction
10:58
Supination / Pronation
11:58
Depression / Elevation
13:10
Retraction / Protraction
13:21
Circumduction
13:35
Synovial Joint Types (By Movement)
13:56
Hinge
14:04
Pivot
14:53
Gliding
15:15
Ellipsoid
15:57
Saddle
16:29
Ball & Socket
17:14
Knee Joint
17:49
Typical Synovial Joint Parts
18:03
Menisci
18:32
ACL Anterior Cruciate
19:50
PCL Posterior Cruciate
20:34
Patellar Ligament
20:56
Joint Disorders / Conditions
21:45
Arthritis
21:48
Bunions
23:26
Bursitis
24:33
Dislocations
25:23
Hyperextension
26:01
Muscular System

53m 7s

Intro
0:00
Functions of Muscles
0:06
Movement
0:09
Maintaining Body Position
1:11
Support of Soft Tissues
1:25
Regulating Entrances / Exits
1:56
Maintaining Body Temperature
2:33
3 Major Types of Muscle Cells (Fibers)
2:58
Skeletal (Striated)
3:21
Smooth
4:11
Cardiac
4:54
Skeletal Muscle Anatomy
5:49
Fascia
6:24
Epimysium
6:47
Fascicles
7:21
Perimysium
7:38
Muscle Fibers
8:04
Endomysium
8:31
Myofibrils
8:49
Sarcomeres
9:20
Skeletal Muscle Anatomy Images
9:32
Sarcomere Structure
12:33
Myosin
12:40
Actin
12:45
Z Line
12:51
A Band
13:11
I Band
13:39
M Line
14:10
Another Depiction of Sarcomere Structure
14:34
Sliding Filament Theory
15:11
Explains How Sarcomeres Contract
15:14
Tropomyosin
15:24
Troponin
16:02
Calcium Binds to Troponin, Causing It to Shift Tropomyosin
17:31
Image Examples
18:35
Myosin Heads Dock and Make a Power Stroke
19:02
Actin Filaments Are Pulled Together
19:49
Myosin Heads Let Go of Actin
19:59
They 'Re-Cock' Back into Position for Another Docking
20:19
Relaxation of Muscles
21:11
Ending Stimulation at the Neuromuscular Junction
21:50
Getting Calcium Ions Back Into the Sarcophasmic Reticulum
23:59
ATP Availability
24:15
Rigor Mortis
24:45
More on Muscles
26:22
Oxygen Debt
26:24
Lactic Acid
28:29
Creatine Phosphate
28:55
Fast vs. Slow Twitch Fibers
29:57
Muscle Names
32:24
4 Characteristics: Function, Location, Size, Orientation
32:27
Examples
32:36
Major Muscles
33:51
Head
33:52
Torso
38:05
Arms
40:47
Legs
42:01
Muscular Disorders
45:02
Muscular Dystrophy
45:08
Carpel Tunnel
45:56
Hernia
47:07
Ischemia
47:55
Botulism
48:22
Polio
48:46
Tetanus
49:06
Rotator Buff Injury
49:54
Mitochondrial Diseases
50:11
Compartment Syndrome
50:54
Fibrodysplasia Ossificans Progressiva
51:44
Nervous System Part I: Neurons

40m 7s

Intro
0:00
Neuron Function
0:06
Basic Cell of the Nervous System
0:07
Sensory Reception
0:31
Motor Stimulation
0:47
Processing
1:07
Form = Function
1:33
Neuron Anatomy
1:47
Cell Body
2:17
Dendrites
2:34
Axon Hillock
3:00
Axon
3:17
Axolemma
3:38
Myelin Sheaths
4:07
Nodes of Ranvier
5:08
Axon Terminals
5:31
Synaptic Vesicles
5:59
Synapse
7:08
Neuron Varieties
9:04
Forms of Neurons Can Vary Greatly
9:08
Examples
9:11
Action Potentials
10:57
Electrical Changes Along a Neuron Membrane That Allow Signaling to Occur
11:17
Na+ / K+ Channels
11:24
Threshold
12:39
Like an 'Electric Wave'
13:50
A Neuron At Rest
13:56
Average Neuron at Rest Has a Potential of -70 mV
14:00
Lots of Na+ Outside
15:44
Lots of K+ Inside
16:15
Action Potential Steps
16:37
Threshold Reached
17:58
Depolarization
18:29
Repolarization
19:38
Hyperpolarization
20:41
Back to Resting Potential
21:05
Action Potential Depiction
21:38
Intracellular Space
21:43
Extracellular Space
21:46
Saltatory Conduction
22:41
Myelinated Neurons
22:49
Propagation is Key to Spreading Signal
23:16
Leads to the Axon Terminals
24:07
Synapses and Neurotransmitters
24:59
Definition of Synapse
25:04
Definition of Neurotransmitters
12:13
Example
26:06
Neurotransmitter Function Across a Synapse
27:19
Action Potential Depolarizes Synaptic Knob
27:28
Calcium Enters Synaptic Cleft to Trigger Vesicles to Fuse with Membrane
27:47
Ach Binds to Receptors on the Postsynaptic Membrane
29:08
Inevitable the Ach is Broken Down by Acetylcholinesterase
30:20
Inhibition vs. Excitation
30:44
Neurotransmitters Have an Inhibitory or Excitatory Effect
31:03
Sum of Two or More Neurotransmitters in an Area Dictates Result
31:13
Example
31:18
Neurotransmitter Examples
34:18
Norepinephrine
34:25
Dopamine
34:52
Serotonin
37:34
Endorphins
38:00
Nervous System Part 2: Brain

1h 7m 43s

Intro
0:00
The Brain
0:07
Part of the Central Nervous System
1:06
Contains Neurons and Neuroglia
1:22
Brain Development
4:34
Neural Tube
4:39
At 3 Weeks
5:03
At 6 Weeks
6:21
At Birth
8:05
Superficial Brain Structure
10:08
Grey vs. White Matter
10:43
Convolution
11:29
Gyrus
12:26
Lobe
13:16
Sulcus
13:39
Fissure
14:09
Cerebral Cortex
14:31
The Cerebrum
14:57
The 'Higher Brain'
15:00
Corpus Callosum
15:53
Divided Into Lobes
16:16
Frontal Lobe
16:41
Involved in Intelligent Thought, Planning, Sense of Consequence, and Rationalization
16:50
Prefrontal Cortex
17:09
Phineas Gage Example
17:21
Primary Motor Cortex
19:05
Broca's Area
20:38
Parietal Lobe
21:34
Primary Somatosensory Cortex
21:50
Wernicke Area
24:06
Imagination and Dreaming
25:21
Gives A Sense of Where Your Body Is in Space
25:44
Temporal Lobe
26:18
Auditory Cortex
26:24
Auditory Association Area
27:00
Olfactory Cortex
27:35
Hippocampi
27:58
Occipital Lobe
28:39
Visual Cortex
28:42
Visual Association Area
28:51
Corpus Callosum
30:07
Strip of White Matter That Connects the Hemispheres of the Cerebrum
30:09
Cutting This Will Help Minimize Harmful Seizures in Epileptics
30:41
Example
31:34
Limbic System
33:22
Establish Emotion, Link Higher and Lower Brain Functions, and Helps with Memory Storage
33:32
Amygdala
33:40
Cingulate Gyrus
34:50
Hippocampus
35:57
Located Within the Temporal Lobes
36:21
Allows Consolidation of Long Term memories
36:33
Patient 'H.M.'
39:03
Basal Nuclei
42:30
Coordination of Learned Movements
42:34
Inhibited by Dopamine
43:14
Olfactory Bulbs / Tracts
43:36
The Only Nerves That Go Directly Into the Cerebrum
44:11
Lie Just Inferior to Prefrontal Cortex of the Frontal Lobe
44:31
Ventricles
44:41
Cavities Deep Within the Cerebrum
44:43
Generate CSF
45:47
Importance of CSF
46:17
Diencephalon
46:39
Thalamus
46:55
Hypothalamus
47:14
Pineal Gland
49:30
Mesencephalon
50:17
Process Visual / Auditory Data
50:38
Reflexive Somatic Motor Responses Generated Here
50:44
Maintains Consciousness
51:07
Pons
51:15
Links Cerebellum With Other Parts of the Brain and Spinal Cord
51:33
Significant Role in Dreaming
51:52
Medulla Oblongata
51:57
Interior Part of Brain Stem
52:02
Contains the Cardiovascular, vasomotor, and Respiratory Centers
52:16
Reticular Formation
53:17
Numerous Nerves Ascend Into the Brain Through Here
53:35
Cerebellum
54:02
'Little Brain' in Latin
54:04
Inferior to Occipital Lobe, Posterior to Pons / Medulla
54:06
Arbor Vitae
54:29
Coordinates Motor Function and Balance
54:51
Meninges
55:39
Membranes That Wrap Around the Superficial Portion of the Brain and Spinal Cord
55:41
Helps Insulate the Central Nervous System and Regulate Blood Flow
55:55
Brain Disorders / Conditions
58:35
Seizures
58:39
Concussions
1:00:11
Meningitis
1:01:01
Stroke
1:01:42
Hemorrhage
1:02:44
Aphasia
1:03:08
Dyslexia
1:03:22
Disconnection Syndrome
1:04:11
Hydrocephalus
1:04:41
Parkinson Disease
1:05:17
Alzheimer Disease
1:05:50
Nervous System Part 3: Spinal Cord & Nerves

32m 6s

Intro
0:00
Nervous System Flowchart
0:08
Spinal Cord
3:59
Connect the Body to the Brain
4:01
Central Canal Contains CSF
4:59
Becomes the Cauda Equina
5:17
Motor vs. Sensory Tracts
6:07
Afferent vs. Efferent Neurons
7:01
Motor-Inter-Sensory
8:11
Dorsal Root vs. Ventral Root
9:07
Spinal Meninges
9:21
Sympathetic vs. Parasympathetic
10:28
Fight or Flight
10:51
Rest and Digest
13:01
Reflexes
15:07
'Reflex Arc'
15:20
Types of Reflexes
17:00
Nerve Anatomy
19:49
Epineurium
20:19
Fascicles
20:27
Perineurium
20:51
Neuron
20:58
Endoneurium
21:06
Nerve Examples
21:43
Vagus Nerve
21:48
Sciatic Nerve
23:18
Radial Nerve
24:04
Facial Nerves
24:14
Optic Nerves
24:28
Spinal Cord Medical Terms
24:42
Lumbar Puncture
24:49
Epidural Block
25:57
Spinal Cord/ Nerve Disorders and Conditions
26:50
Meningitis
26:56
Shingles
27:12
Cerebral / Nerve Palsy
28:18
Hypesthesia
28:45
Multiple Sclerosis
29:46
Paraplegia/ Quadriplegia
30:48
Vision

58m 38s

Intro
0:00
Accessory Structures of the Eye
0:04
Eyebrows
0:15
Eyelids
1:22
Eyelashes
2:11
Skeletal Muscles
3:33
Conjunctiva
3:56
Lacrimal Glands
4:50
Orbital Fat
6:45
Outer (Fibrous) Tunic
7:24
Sclera
8:01
Cornea
8:46
Middle (Vascular) Tunic
10:27
Choroid
10:37
Iris
12:25
Pupil
14:54
Lens
15:18
Ciliary Bodies
16:51
Suspensory Ligaments
17:45
Vitreous Humor
18:13
Inner (Neural)Tunic
19:31
Retina
19:40
Photoreceptors
20:38
Macula
21:32
Optic Disc
22:48
Blind Spot Demonstration
23:34
Lens Function
25:28
Concave
25:48
Convex
26:58
Clear Image
28:11
Accommodation Problems
28:31
Emmetropia
28:32
Myopia
30:46
Hyperopia
32:00
Photoreceptor Structure
34:15
Rods
34:32
Cones
35:06
Bipolar Cells
37:32
Inner Segment
38:28
Outer Segment
38:43
Pigment Epithelium
41:11
Visual Pathways to the Occipital Lobe
41:58
Stereoscopic Vision
42:02
Optic Nerves
43:32
Optic Chiasm
44:25
Optic Tract
46:28
Occipital Lobe
46:58
Vision Disorders / Conditions
48:03
Myopia / Hyperopia
48:10
Cataracts
49:11
Glaucoma
50:22
Astigmatism
52:14
Color Blindness
53:12
Night Blindness
54:51
Scotomas
55:19
Retinitis Pigmentosa
55:46
Detached Retina
56:06
Hearing

36m 57s

Intro
0:00
External Ear
0:04
Auricle
0:22
External Acoustic Meatus
1:49
Hair
2:32
Ceruminous Glands
3:04
Tympanic Membrane
3:53
Middle Ear
5:31
Tympanic Cavity
5:47
Auditory Tube
5:50
Auditory Ossicles
7:52
Tympanic Muscles
9:19
Auditory Ossicles
12:02
Inner Ear
13:06
Cochlea
13:23
Vestibule
13:30
Semicircular Canals
13:36
Cochlea
13:57
Organ of Corti
14:44
Vestibular Duct
15:03
Cochlear Duct
15:11
Tympanic Duct
15:20
Basilar Membrane
16:30
Tectorial Membrane
17:02
Hair Cells
17:17
Nerve Fibers
20:54
How Sounds Are Heard
21:30
Sound Waves Hit the Tympanum
22:10
Auditory Ossicles are Vibrated
22:23
Stapes Vibrates Oval Window
22:31
Basilar Membrane is Vibrated in Turn
22:35
Hair Cells are Moved with Respect to Tectorial Membrane
22:46
Cochlear Nerve Fibers Take Signals to Temporal Lobes
23:24
Frequency and Decibels
23:30
Frequency Deals with Pitch
23:36
Decibels Deal with Loudness
25:30
Vestibule
27:54
Contains the Utricle and Saccule
28:22
Maculae
29:29
Semicircular Canals
31:05
3 Semicircular Canals = 3 Dimensions
31:12
Movement Gives a Sense of How Your Head is Rotating in 3 Dimensions
31:28
Each Contains an Ampulla
31:49
Hearing Conditions / Disorders
33:20
Conductive Deafness
33:24
Tinnitus
34:05
Otitis Media
34:51
Motion Sickness
35:19
Ear Infections
36:31
Smell, Taste & Touch

36m 41s

Intro
0:00
Nasal Anatomy
0:05
The Nose
0:11
Nasal Cavity
0:58
Olfaction
3:27
Sense of Smell
3:28
Olfactory Epithelium
4:58
Olfactory Receptors
7:23
Respond to Odorant Molecules
7:24
Lots of Turnover of Olfactory Receptor Cells
8:25
Smells Noticed in Small Concentrations
9:07
Anatomy of Taste
12:41
Tongue
12:45
Pharynx / Larynx
14:11
Salivary Glands
14:31
Papilla Structure
16:56
Gustatory Cells
17:39
Taste Hairs
18:04
Transitional Cells
18:28
Basal Cells
18:33
Nerve Fibers
18:48
Taste Sensations
19:06
Sweet
19:49
Salty
20:16
Bitter
20:28
Sour
20:46
Umami
20:31
Water
22:07
PTC
23:11
Touch
25:00
Nociceptors
25:08
Mechanoreceptors
25:14
Nociceptors
26:30
Sensitive To…
26:41
Fast vs. Slow Pain
28:12
Mechanoreceptors
31:15
Tactile Receptors
31:21
Baroreceptors
35:20
Proprioceptors
36:07
The Heart

45m 20s

Intro
0:00
Heart Anatomy
0:04
Pericardium
0:11
Epicardium
1:09
Myocardium
1:24
Endocardium
1:49
Atria and Ventricles
2:18
Coronary Arteries
3:25
Arteries / Veins
4:14
Fat
4:31
Sequence of Blood Flow #1
5:06
Vena Cava
5:24
Right Atrium
6:18
Tricuspid Valve
6:26
Right Ventricle
6:49
Pulmonary Valve
7:14
Pulmonary Arteries
7:35
Sequence of Blood Flow #2
8:22
Lungs
8:24
Pulmonary Veins
8:26
Left Atrium
8:36
Left Ventricle
9:00
Bicuspid Valve
9:08
Aortic Valve
10:15
Aorta
10:23
Body
11:20
Simplified Blood Flow Diagram
11:44
Heart Beats and Valves
16:09
'Lubb-Dubb'
16:19
Atrioventricular (AV) Valves
16:47
Semilunar Valves
17:04
Systole and Diastole
19:09
Systole
19:14
Diastole
19:23
Valves Respond to Pressure Changes
20:29
Cardiac Output
21:36
Cardiac Cycle
22:59
Cardiac Conduction System
24:52
Sinoatrial (SA) Node
25:44
Atrioventricular (AV) Node
27:12
Electrocardiogram (EKG or ECG)
28:46
P Wave
29:10
QRS Complex
30:14
T Wave
31:23
Arrhythmias
32:14
Heart Conditions / Treatments
35:12
Myocardial Infarction (MI)
35:14
Angina Pectoris
36:23
Pericarditis
38:07
Coronary Artery Disease
38:26
Angioplasty
38:47
Coronary Artery Bypass Graft
39:53
Tachycardia / Bradycardia
40:51
Fibrillation
41:54
Heart Murmur
43:22
Mitral Valve Prolapse
44:53
Blood Vessels

39m 58s

Intro
0:00
Types of Blood Vessels
0:05
Arteries
0:09
Arterioles
0:19
Capillaries
0:38
Venules
0:55
Veins
1:16
Vessel Structure
1:21
Tunica Externa
1:39
Tunica Media
2:29
Tunica Interna
3:18
Differences Between Arteries and Veins
4:22
Artery Walls are Thicker
4:34
Veins Have Valves
6:07
From Artery to Capillary
6:38
From Capillary to Vein
9:39
Capillary Bed
11:11
Between Arterioles and Venules
11:23
Precapillary Sphincters
11:30
Distribution of Blood
12:17
Systematic Venous System
12:36
Systematic Arterial System
13:23
Pulmonary Circuit
13:36
Heart
13:46
Systematic Capillaries
13:53
Blood Pressure
14:35
Cardiac Output
15:07
Peripheral Resistance
15:24
Systolic / Diastolic
16:37
Return of Blood Through Veins
20:37
Valves
21:00
Skeletal Muscle Contractions
21:30
Regulation of Blood Vessels
22:50
Baroreceptor Reflexes
22:57
Antidiuretic Hormone
23:31
Angiotensin II
24:40
Erythropoietin
24:57
Arteries / Vein Examples
26:54
Aorta
26:59
Carotid
27:13
Brachial
27:23
Femoral
27:27
Vena Cava
27:38
Jugular
27:48
Brachial
28:04
Femoral
28:09
Hepatic Veins
29:03
Pulse Sounds
29:19
Carotid
29:27
Radial
29:53
Femoral
30:39
Popliteal
30:47
Temporal
30:52
Dorsalis Pedis
31:10
Blood Vessel Conditions / Disorders
31:29
Hyper / Hypotension
31:33
Arteriosclerosis
33:05
Atherosclerosis
33:35
Edema
33:58
Aneurysm
33:34
Hemorrhage
35:38
Thrombus
35:50
Pulmonary Embolism
36:44
Varicose Veins
36:54
Hemorrhoids
37:46
Angiogenesis
39:06
Blood

41m 25s

Intro
0:00
Blood Functions
0:04
Transport Nutrients, Gases, Wastes, Hormones
0:09
Regulate pH
0:30
Restrict Fluid Loss During Injury
1:02
Defend Against Pathogens and Toxins
1:12
Regulate Body Temperature
1:21
Blood Components
1:59
Erythrocytes
2:34
Thrombocytes
2:50
Leukocytes
3:07
Plasma
3:17
Blood Cell Formation
6:55
Red Blood Cells
8:16
Shaped Like Biconcave Discs
8:25
Enucleated
9:08
Hemoglobin is the Main Protein at Work
10:03
Oxyhemoglobin vs. Deoxyhemoglobin
10:32
Breakdown and Renewal of RBCs
12:03
RBCs are Engulfed and Rupture
12:15
Hemoglobin is Broken Down
12:23
Erythropoiesis Makes New RBCs
14:38
Blood Transfusions #1
15:02
A Blood
15:29
B Blood
17:28
AB Blood
19:27
O Blood
20:53
Rh Factor
21:54
Blood Transfusions #2
24:31
White Blood Cells
25:33
Can Migrate Out of Blood Stream
25:46
Amoeboid Movement
26:06
Most Do Phagocytosis
26:57
Granulocytes
27:25
Neutrophils
27:44
Eosinophils
28:11
Basophils
29:20
Agranulocytes
29:37
Monocytes
29:49
Lymphocytes
30:30
Platelets
32:42
Release Chemicals to Help Clots Occur
33:04
Temporary Patch on Walls of Damaged Vessels
33:11
Contraction to Reduce Clot Size
33:22
Hemostasis
33:40
Vascular Phase
33:53
Platelet Phase
34:30
Coagulation Phase
35:15
Fibrinolysis
36:12
Blood Conditions / Disorders
36:29
Hemorrhage
36:41
Thrombus
36:48
Embolism
36:59
Anemia
37:14
Sickle Cell Disease
38:04
Hemophilia
39:19
Leukemia
40:47
Respiratory System

1h 2m 59s

Intro
0:00
Functions of the Respiratory System
0:05
Moves Air In and Out of Body
0:37
Protects the Body from Dehydration
0:50
Produce Sounds
2:00
Upper Respiratory Tract #1
2:15
External Nares
2:34
Vestibule
2:42
Nasal Septum
3:02
Nasal Conchae
4:06
Upper Respiratory Tract #2
4:43
Nasal Mucosa
4:53
Pharynx
6:01
Larynx
8:34
Epiglottis
8:48
Glottis
9:03
Cartilage
9:27
Hyoid Bone
12:09
Ligaments
13:04
Vocal Cords
13:15
Sound Production
13:41
Air Passing Through the Glottis Vibrates the Vocal Folds
13:43
Males Have Longer Cords
15:32
Speech =Phonation + Articulation
15:41
Trachea
16:42
'Windpipe'
17:42
Respiratory Epithelium
18:45
Bronchi and Bronchioles
20:56
Primary - Secondary - Tertiary
21:41
Smooth Muscles
22:29
Bronchioles
22:46
Bronchodilation vs. Bronchoconstriction
23:42
Alveoli
24:30
Air Sacks Within the Lungs
24:39
Alveolar Bundle is Surrounded by a Capillary Network
27:24
Surfactant
28:47
Lungs
30:40
Lobes
30:48
Right Lung is Broader; Left Lung is Longer
31:35
Spongy Appearance
32:11
Surrounded by Membrane
32:28
Pleura
32:52
Parietal Pleura
32:59
Visceral Pleura
33:38
Breathing Mechanism
35:27
Diaphragm
35:32
Intercostal Muscles
38:21
Diaphragmatic vs. Costal Breathing
39:10
Forced Breathing
39:44
Respiratory Volumes
41:33
Partial Pressures of Gases
46:02
Major Atmospheric Gases
46:14
Diffusion
47:00
Oxygen Moves Out of Alveoli and Carbon Dioxide Moves In
48:37
Respiratory Conditions / Disorders
51:21
Asthma
51:25
Emphysema
52:57
Lung Cancer
53:45
Laryngitis / Bronchitis
54:25
Cystic Fibrosis
55:38
Decompression Sickness
56:29
Tuberculosis
57:31
SIDS
59:10
Pneumonia
1:00:00
Pneumothorax
1:01:07
Carbon Monoxide Poisoning
1:01:21
Digestive System

59m 28s

Intro
0:00
Functions of the Digestive System
0:05
Ingestion
0:09
Mechanical Breakdown
0:15
Digestion
0:33
Secretion
0:59
Absorption
1:22
Excretion
1:33
Alimentary Canal (GI Tract)
1:38
Mouth
2:13
Pharynx
2:18
Esophagus
2:20
Stomach
2:29
Small Intestine
2:33
Large Intestine
2:41
Rectum
2:49
Anus
2:51
Oral Cavity (Mouth)
2:53
Salivary Glands
2:58
Saliva
3:59
Tongue
5:04
Teeth
5:28
Hard Palate / Soft Palate
5:42
Teeth
6:19
Deciduous Teeth
9:27
Adult Teeth
9:56
Incisors
10:14
Cuspids
10:42
Bicuspids
11:07
Molars
11:27
Swallowing
14:06
Tongue
14:19
Pharyngeal Muscles
14:57
Soft Palate
15:05
Epiglottis
15:23
Esophagus
16:41
Moves Food Into the Stomach Through 'Peristalsis'
16:54
Mucosa
18:28
Submucosa
18:30
Muscular Layers
18:54
Stomach #1
19:58
Food Storage, Mechanical / Chemical Breakdown, and Emptying of Chyme
20:42
4 Layers: Mucosa, Submuscoa, Muscular Layers, Serosa
21:27
4 Regions: Cardia, Fundus, Body, Pylorus
22:51
Stomach #2
24:43
Rugae
25:20
Gastric Pits
25:54
Gastric Glands
26:04
Gastric Juice
26:24
Gastrin, Ghrelin
28:18
Small Intestine
29:07
Digestion and Absorption
29:09
Duodenum, Jejunum, Ileum
29:46
Peristalsis
29:57
Intestinal Villi
30:22
Vermiform Appendix
32:53
Vestigial Structure!
33:40
Appendicitis / Appendectomy
35:40
Large Intestine
36:04
Reabsorption of Water and Formation of Solid Feces
36:20
Ascending Colon
37:10
Transverse Colon
37:16
Descending Colon
37:22
Sigmoid Colon
37:36
Rectum and Anus
37:48
Rectum
37:51
Anus
38:38
Hemorrhoids
39:24
Accessory Organs
41:13
Liver
41:26
Gall Bladder
41:28
Pancreas
41:30
Liver
41:40
Metabolism
43:21
Glycogen Storage
43:34
Waste Product Removal
44:42
Bile Production
44:50
Vitamin Storage
45:04
Breakdown of Drugs
45:25
Phagocytosis, Antigen Presentation
46:24
Synthesis of Plasma Proteins
47:05
Removal of Hormones
47:19
Removal of Antibodies
47:31
Removal of RBCs
48:07
Removal / Storage of Toxins
48:21
Gall Bladder
48:50
Stores Bile Made by Liver
48:53
Common Hepatic Duct
49:24
Common Bile Duct Connects to the Duodenum
49:31
Pancreas
51:28
Pinkish-Gray Organ
51:45
Produces Digestive Enzymes and Buffers
52:05
Digestive Conditions / Disorders
52:50
Gastritis
52:54
Ulcers
53:03
Gallstones
54:09
Cholera
54:51
Hepatitis
55:14
Jaundice
55:31
Cirrhosis
56:34
Constipation
56:52
Diarrhea
57:23
Lactose Intolerance
57:37
Gingivitis
58:24
Metabolism & Nutrition

1h 17m 2s

Intro
0:00
Metabolism Basics
0:06
Metabolism
0:10
Catabolism
0:58
Anabolism
1:12
Nutrients
2:45
Carbohydrates
2:57
Lipids
3:01
Proteins
3:04
Nucleic Acids
3:23
Vitamins
3:54
Minerals
4:32
Carbohydrate Structure
5:13
Basic Sugar Structure
5:42
Monosaccharides
7:48
Disaccharides
7:54
Glycosidic Linkages
8:07
Polysaccharides
9:17
Dehydration Synthesis vs. Hydrolysis
10:27
Water Soluble
10:55
Energy Source
11:18
Aerobic Respiration
11:39
Glycolysis
13:25
Krebs Cycle
13:34
Oxidative Phosphorylation
13:44
ATP Structure and Function
14:08
Adenosine Triphosphate
14:11
ATP is Broken Down Into ADP + P
16:26
ADP + P are Put Together to Make ATP
16:39
Glycolysis
17:18
Breakdown of Sugar Into Pyruvate
17:42
Occurs in the Cytoplasm
17:55
Phase I
18:13
Phase II
19:01
Phase III
20:27
Krebs Cycle
21:54
Citric Acid Cycle
21:57
Pyruvates Modify Into 'acetyl-CoA'
22:23
Oxidative Phosphorylation
29:36
Anaerobic Respiration
34:33
Lactic Acid Fermentation
34:52
Produces Only the ATP From Glycolysis
36:05
Gluconeogenesis
37:36
Glycogenesis
39:16
Glycogenolysis
39:27
Lipid Structure and Function
39:58
Fats
40:00
Non-Polar
41:42
Energy Source, Insulation, Hormone Synthesis
42:02
Saturated vs. Unsaturated Fats
43:18
Saturated Fats
43:22
Unsaturated Fats
44:30
Lipid Catabolism
46:11
Lipolysis
46:17
Beta-Oxidation
46:56
Lipid Synthesis
48:17
Lipogenesis
48:21
Lipoproteins
48:51
Protein Structure and Function
51:48
Made of Amino Acids
51:59
Water-Soluble
52:23
Support
53:03
Movement
53:23
Transport
53:34
Buffering
53:49
Enzymatic Action
54:01
Hormone Synthesis
54:13
Defense
54:24
Amino Acids
54:56
20 Different 'R Groups'
54:59
Essential Amino Acids
55:19
Protein Structure
56:54
Primary Structure
56:59
Secondary Structure
57:29
Tertiary Structure
58:28
Quaternary Structure
59:20
Vitamins
59:40
Fat-Soluble
1:01:46
Water-Soluble
1:02:15
Minerals
1:04:01
Functions
1:04:14
Examples
1:04:51
Balanced Diet
1:05:39
Grains
1:05:52
Vegetables and Fruits
1:06:00
Dairy
1:06:36
Meat/ Beans
1:06:54
Oils
1:07:52
Nutrition Facts
1:08:44
Serving Size
1:08:55
Calories
1:09:50
Fat-Soluble
1:10:45
Cholesterol
1:13:04
Sodium
1:13:58
Carbohydrates
1:14:26
Protein
1:16:01
Endocrine System

44m 37s

Intro
0:00
Hormone Basics
0:05
Hormones
0:38
Classes of Hormones
2:22
Negative vs. Positive Feedback
3:22
Negative Feedback
3:25
Positive Feedback
5:16
Hypothalamus
6:20
Secretes Regulatory Hormones
7:18
Produces ADH and Oxycotin
7:44
Controls Endocrine Action of Adrenal Glands
7:57
Anterior Pituitary Gland
8:27
Prolactin
9:16
Corticotropin
9:39
Thyroid-Stimulating Hormone
9:47
Gonadotropins
9:52
Growth Hormone
11:04
Posterior Pituitary Gland
12:29
Antidiuretic Hormone
12:38
Oxytocin
13:37
Thyroid Gland Anatomy
15:16
Two Lobes United by an Isthmus
15:44
Contains Follicles
16:04
Thyroid Gland Physiology
16:50
Thyroxine
17:04
Triiodothyroine
17:36
Parathyroid Anatomy / Physiology
18:52
Secrete Parathyroid Hormone (PTH)
19:13
Adrenal Gland Anatomy
20:09
Contains Cortex and Medulla
21:00
Adrenal Cortex Physiology
21:40
Aldosterone
22:12
Glucocorticoids
22:35
Androgens
23:18
Adrenal Medulla Physiology
23:53
Epinephrine
24:06
Norepinephrine
24:12
Fight or Flight
24:22
Contribute to…
24:32
Kidney Hormones
26:11
Calcitriol
26:20
Erythropoietin
27:00
Renin
27:45
Pancreas Anatomy
28:18
Exocrine Pancreas
29:07
Endocrine Pancreas
29:22
Pancreas Physiology
29:50
Glucagon
29:57
Insulin
30:54
Somatostatin
31:50
Pineal Gland Anatomy / Physiology
32:10
Contains Pinealocytes
32:33
Produces Melatonin
32:59
Thymus Anatomy / Physiology
34:17
Max Size Before Puberty
34:49
Secrete Thymosins
35:18
Gonad Hormones
35:45
Testes
35:51
Ovaries
36:20
Endocrine Conditions / Disorders
37:28
Diabetes Type I and II
37:32
Diabetes Type Insipidus
39:25
Hyper / Hypoglycemia
40:01
Addison Disease
40:28
Hyper / Hypothyroidism
41:00
Cretinism
41:30
Goiter
41:59
Pituitary Gigantism / Dwarfism
42:39
IDD Iodized Salt
43:30
Urinary System

35m 8s

Intro
0:00
Functions of the Urinary System
0:05
Removes Metabolic Waste
0:14
Regulates Blood Volume and Blood Pressure
0:31
Regulates Plasma Concentrations
0:49
Stabilize Blood pH
1:04
Conserves Nutrients
1:42
Organs / Tissues of the Urinary System
1:51
Kidneys
1:58
Ureters
2:17
Urinary Bladder
2:25
Urethra
2:34
Kidney Anatomy
2:47
Renal Cortex
4:21
Renal Medulla
4:41
Renal Pyramid
5:00
Major / Minor Calyx
5:36
Renal Pelvis
6:07
Hilum
6:18
Blood Flow to Kidneys
6:41
Receive Through Renal Arteries
7:11
Leaves Through Renal Veins
9:08
Regulated by Renal Nerves
9:21
Nephrons
9:27
Glomerulus
10:21
Bowman's Capsule
10:42
Proximal Convoluted Tubule (PCT)
11:31
Loop of Henle
11:42
Distal Convoluted Tubule (DCT)
12:01
Glomerular Filtration
12:40
Glomerular Capillaries are Fenestrated
12:47
Blood Pressure Forces Water Into the Capsular Space
13:47
Important Nutrients
13:57
Proximal Convoluted Tubule (PCT)
14:25
Lining is Simple Cubodial Epithelium with Microvilli
14:47
Reabsorption of Nutrients, Ions, Water and Plasma
15:26
Loop of Henle
16:28
Pumps Out Sodium and Chloride Ions
17:09
Concentrate Tubular Fluid
17:20
Distal Convoluted Tubule (DCT)
17:28
Differs From the PCT
17:39
Three Basic Processes
17:59
Collecting System
18:35
Final Filtration, Secretion, and Reabsorption
18:52
Concentrated Urine Passes through the Collecting Duct
19:04
Fluid Empties Into Minor Calyx
19:20
Major Calyx Leads to Renal Pelvis
19:26
Summary of Urine Formation
19:35
Filtration
19:40
Reabsorption
20:04
Secretion
20:35
Urine
21:15
Urea
21:31
Creatinine
21:55
Uric Acid
22:09
Urobilin
22:23
It's Sterile!
23:43
Ureters
24:55
Connects Kidneys to Urinary Bladder
25:00
Three Tissue Layers
25:17
Peristalsis
25:38
Urinary Bladder
26:08
Temporary Reservoir for Urine
26:12
Rugae
26:44
Trigone
26:59
Internal Urethral Sphincter
27:10
Urethra
27:48
Longer in Males than Females
28:00
External Urethral Sphincter
28:46
Micturition
29:14
Urinary Conditions / Disorders
29:47
Urinary Tract Infection (UTI)
29:50
Kidney Stones (Renal Calculi)
30:26
Kidney Dialysis
31:47
Glomerulonephritis
33:29
Incontinence
34:25
Lymphatic System

44m 23s

Intro
0:00
Lymphatic Functions
0:05
Production, Maintenance, and Distribution of Lymphocytes
0:08
Lymphoid System / Immune System
1:26
Lymph Network
1:34
Lymph
1:40
Lymphatic Vessels
2:26
Lymph Nodes
2:37
Lymphoid Organs
2:54
Lymphocytes
3:11
Nonspecific Defenses
3:25
Specific Defenses
3:47
Lymphatic Vessels
4:06
Larger Lymphatic Vessels
4:40
Lymphatic Capillaries
5:17
Differ From Blood Capillaries
5:47
Lymph Nodes
6:51
Concentrated in Neck, Armpits, and Groin
7:05
Functions Like a Kitchen Water Filter
7:52
Thymus
8:58
Contains Lobules with a Cortex and Medulla
9:18
Promote Maturation of Lymphocytes
10:36
Spleen
10:43
Pulp
12:04
Red Pulp
12:19
White Pulp
12:25
Nonspecific Defenses
13:00
Physical Barriers
13:18
Phagocyte Cells
14:17
Immunological Surveillance
14:55
Interferons
16:05
Inflammation
16:37
Fever
17:07
Specific Defenses
18:16
Immunity
18:31
Innate Immunity
18:41
Acquired Immunity
19:04
T Cells
23:58
Cytotoxic T Cells
24:14
Helper T Cells
24:52
Suppressor T Cells
25:09
Activate T Cells
25:40
Major Histocompatibility Complex Proteins (MHC)
26:37
Antigen Presentation
27:58
B Cells
29:44
Responsible for Antibody-Mediated Immunity
29:50
Memory B Cells
30:44
Antibody Structure
32:46
Five Types of Constant Segments
33:45
Primary vs. Secondary Response
34:51
Immune Conditions / Disorders
35:35
Allergy
35:38
Anaphylactic Shock
37:17
Autoimmune Disease
38:34
HIV / AIDS
39:06
Cancer
40:51
Lymphomas
42:02
Lymphedema
42:21
Graft Rejection
42:48
Tonsillitis
43:23
Female Reproductive System

47m 19s

Intro
0:00
External Genitalia
0:05
Mons Pubis
0:12
Vulva
0:29
Vagina
0:51
Clitoris
1:23
Prepuce
2:10
Labia Minora
2:29
Labia Majora
2:35
Urethra
3:09
Vestibular Glands
3:30
Internal Reproductive Organs
3:47
Vagina
3:51
Uterus
3:57
Fallopian Tubes
4:13
Ovaries
4:19
Vagina
4:28
Passageway for Elimination of Menstrual Fluids
5:13
Receives Penis During Sexual Intercourse
5:31
Forms the Inferior Portion of the Birth Canal
5:34
Hymen
5:42
Uterus
7:21
Provides Protection, Nutritional Support, and Waste Removal for Embryo
7:25
Anteflexion
8:30
Anchored by Ligaments
9:18
Uterine Regions
9:57
Perimetrium
10:56
Myometrium
11:19
Endometrium
11:44
Fallopian Tubes
13:03
Oviducts / Uterine Tubes
13:04
Infundibulum
13:49
Ampulla
15:07
Isthmus
15:12
Peristalsis
15:21
Ovaries
16:06
Produce Female Gametes
16:37
Secrete Sex Hormones
16:47
Ligaments, Artery / Vein
17:18
Mesovarium
17:45
Oogenesis Explanation
17:59
Ovum Production
18:08
Oogonia Undergo Mitosis
18:44
Oogenesis Picture
22:22
Ovarian / Menstrual Cycle
25:48
Menstruation
33:05
Thickened Endometrial Lining Sheds
33:08
1-7 Days
33:37
Ovarian Cycle
33:48
Formation of Primary Follicles
34:20
Formation of Secondary Follicles
34:28
Formation of Tertiary Follicles
34:30
Ovulation
34:37
Formation / Degeneration of Corpus Luteum
34:52
Menarche and Menopause
35:28
Menarche
35:30
Menopause
36:24
Mammaries
38:16
Breast Tissue
38:18
Mammary Gland
39:19
Female Reproductive Conditions / Disorders
41:32
Amenorrhea
41:35
Dysmenorrhea
42:29
Endometriosis
42:40
STDs
43:11
Pelvic Inflammatory Disease (PID)
43:37
Premature Menopause
43:55
Ovarian, Cervical, Breast Cancers
44:20
Hysterectomy
45:37
Tubal Ligation
46:12
Male Reproductive System

36m 35s

Intro
0:00
External Genitalia
0:06
Penis
0:09
Corpora Cavernosa
3:10
Corpus Spongiosum
3:57
Scrotum
4:15
Testes
4:21
Gubernaculum Testis
4:54
Contracts in Male Babies
5:34
Cryptorchidism
5:50
Inside the Scrotal Sac
7:01
Scrotum
7:08
Cremaster Muscle
7:54
Epididymis
8:43
Testis Anatomy
9:50
Lobules
10:03
Septa
11:35
Efferent Ductule
11:39
Epididymis
11:50
Vas Deferens
11:53
Spermatogenesis
12:02
Mitosis
12:14
Meiosis
12:37
Spermiogenesis
12:48
Sperm Anatomy
15:14
Head
15:19
Centrioles
17:01
Mitochondria
17:37
Flagellum
18:29
The Path of Sperm
18:50
Testis
18:58
Epididymis
19:05
Vas Deferens
19:16
Accessory Glands
19:57
Urethra
21:33
Vas Deferens
21:45
Takes Sperm from Epididymides to the Ejaculatory Duct
21:53
Peristalsis
22:35
Seminal Vesicles
23:45
Fructose
24:25
Prostaglandins
24:51
Fibrinogen
25:13
Alkaline Secretions
25:45
Prostate Gland
26:12
Secretes Fluid and Smooth Muscles
26:49
Produces Prostatic Fluid
27:02
Bulbo-Urethral Gland
27:43
Cowper Glands
27:48
Secretes a Thick, Alkaline Mucus
28:13
Semen
28:45
Typical Ejaculation Releases 2-5mL
28:48
Contains Spermatozoa, Seminal Fluid, Enzymes
28:58
Male Reproductive Conditions / Disorders
29:59
Impotence
30:02
Low Sperm Count
30:24
Erectile Dysfunction
31:36
Priapism
32:11
Benign Prostatic Hypertrophy
32:58
Prostatectomy
33:39
Prostate Cancer
33:59
STDs
34:30
Orchiectomy
34:47
Vasectomy
35:10
Embryological & Fetal Development

49m 15s

Intro
0:00
Development Overview
0:05
Fertilization
0:13
Embryological Development
0:23
Fetal Development
1:14
Postnatal Development
1:25
Maturity
1:36
Fertilization Overview
1:39
23 Chromosomes
2:23
Occurs a Day After Ovulation
3:44
Forms a Zygote
4:16
Oocyte Activation
4:33
Block of Polyspermy
4:51
Completion of Meiosis II
6:05
Activation of Enzymes That Increase Metabolism
6:26
Only Nucleus of Sperm Moves Into Oocyte Center
7:04
Cleavage
8:14
Day 0
8:25
Day 1
8:35
Day 2
9:10
Day 3
9:12
Day 4
9:21
Day 6
9:29
Implantation
11:03
Day 8
11:10
Initial Implantation
11:15
Lacunae
11:27
Fingerlike Villi
11:38
Gastrulation
12:39
Day 12
12:48
Ectoderm
14:06
Mesoderm
14:17
Endoderm
14:44
Extraembryonic Membranes
16:17
Yolk Sac
16:28
Amnion
17:28
Allantois
18:05
Chorion
18:27
Placenta
19:28
Week 5
19:50
Decidua Basalis
20:08
Cavity
21:20
Umbilical Cord
22:20
Week 4 Embryo
23:01
Forebrain
23:35
Eye
23:46
Heart
23:54
Pharyngeal Arches
24:02
Arm and Leg Buds
24:53
Tail
25:56
Week 8 Embryo
26:33
Week 12 Fetus
27:36
Ultrasound
28:26
Image of the Fetus
28:28
Sex Can Be Detected
28:54
Week 40 Fetus
29:46
Labor
31:10
False Labor
31:16
True Labor
31:38
Dilation
32:02
Expulsion
33:21
Delivery
33:49
Delivery Problems
33:57
Episiotomy
34:02
Breech Birth
34:39
Caesarian Section
35:41
Premature Delivery
36:12
Conjoined Twins
37:34
Embryological Conditions / Disorders
40:00
Gestational Trophoblastic Neoplasia
40:07
Miscarriage
41:04
Induced Abortions
41:37
Ectopic Pregnancy
41:47
In Vitro Fertilization
43:03
Amniocentesis
44:01
Birth Defects
45:15
Alcohol: Effects & Dangers

27m 47s

Intro
0:00
Ethanol
0:06
Made from Alcohol Fermentation
0:20
Human Liver Can Break Down Ethyl Alcohol
1:40
Other Alcohols
3:06
Ethanol Metabolism
3:33
Alcohol Dehydrogenase Converts Ethanol to Acetaldehyde
3:38
Acetaldehyde is Converted to Acetate
4:01
Factors Affecting the Pace
4:24
Sex and Sex Hormones
4:33
Body Mass
5:30
Medications
5:59
Types of Alcoholic Beverages
6:07
Hard Alcohol
6:14
Wine
6:51
Beer
6:56
Mixed Drinks
8:17
Alcohol's Immediate Effects
8:55
Depressant
9:12
Blood Alcohol Concentration
9:31
100 mg/ dL = 0.1%
10:19
0.05
10:48
0.1
11:29
0.2
11:56
0.3
12:52
Alcohol's Effects on Organs
13:45
Brain
13:59
Heart
14:09
Stomach
14:20
Liver
14:31
Reproductive System
14:37
Misconceptions on Alcohol Intoxication
14:54
Cannot Speed Up the Liver's Breakdown of Alcohol
14:57
Passing Out
16:27
Binge Drinking
17:50
Hangovers
18:40
Alcohol Tolerance
18:51
Acetaldehyde
19:10
Dehydration
19:40
Congeners
20:34
Ethanol is Still in Bloodstream
21:26
Alarming Statistics
22:26
Alcoholism Affects 10+ Million People in U.S. Alone
22:33
Society's Most Expensive Health Problem
22:40
Affects All Physiological Tissues
22:15
Women Drinking While Pregnant
23:57
Fetal Alcohol Syndrome (FAS)
24:06
Genetics
24:26
Health Problems Related to Alcohol
24:57
Alcohol Abuse
25:01
Alcohol Poisoning
25:20
Alcoholism
26:14
Fatty Liver
26:46
Cirrhosis
27:13
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Lecture Comments (20)

3 answers

Last reply by: Bryan Cardella
Wed Dec 17, 2014 4:32 PM

Post by Lee Ross on December 15, 2014

Hi Bryan. 1 question... The movement of Na+ into the axon and K+ out, on your action potential slide. That "pump" is the sodium potassium pump? Also. In regards to the peripheral nervous system, or I guess the nervous system in general what is behind the intensity of a "stimulation"? I'm not sure how to exactly ask my question lol. For example, how does the body distinguish the level of pain you'd feel from the prick of a needle to the pain of it actually puncturing the skin?

1 answer

Last reply by: Bryan Cardella
Sun Oct 19, 2014 2:20 PM

Post by Ray Gaytan on October 18, 2014

Thank You!!!!!!! Very beneficial and helpful. Breaking down the terms in easy level, I am able to see the big picture.

1 answer

Last reply by: Bryan Cardella
Tue Aug 19, 2014 5:56 PM

Post by Ikze Cho on August 19, 2014

in the example of the presynaptic facilitation:
Is it necessary that there is an action potential or are the neurotransmitters from the other neuron enough to stimulate the exocytosis?

5 answers

Last reply by: Johanna Serbousek
Fri Aug 8, 2014 6:42 PM

Post by Gaurav Kumar on July 7, 2014

Do action potentials occur in each node of the neuron?

0 answers

Post by Madina Abdullah on April 25, 2014

really helpful,thank you

1 answer

Last reply by: Bryan Cardella
Mon Mar 10, 2014 6:10 PM

Post by chris sickenberger on March 10, 2014

your awesome Bryan. its so clear after one of your lessons

0 answers

Post by Sandra Egwuonwu on February 16, 2014

*am

1 answer

Last reply by: Bryan Cardella
Mon Feb 17, 2014 11:04 AM

Post by Sandra Egwuonwu on February 16, 2014

I am basically paid to be an educator student mainly because of you...You teach excellently well.

Nervous System Part I: Neurons

  • Neuron (nerve cell) functions include sensory reception, motor stimulation, and processing
  • Neuron anatomy terms: cell body, dendrites, axon hillock, axon, axolemma, myelin sheath (Schwann cell), Nodes of Ranvier, axon terminals, synaptic vesicles, synapse
  • Neuron form = neuron function
  • Action potentials are electrical changes along a neuron’s membrane that get a signal across the cell
  • Sodium and potassium are the main players in the electrical wave (it’s an all-or-none activity)
  • Action potential steps: threshold reached, depolarization, repolarization, hyperpolarization, and then back to resting potential
  • Saltatory conduction involves the electrical signaling jumping over myelin sheaths
  • Neurotransmitters get the signal across a synapse from the presynaptic neuron to its effector (typically a postsynaptic neuron)
  • Neurotransmitters have an excitatory or inhibitory effect on neurons or effected tissues
  • Examples of neurotransmitters: norepinephrine, dopamine, serotonin, and endorphins
  • Did you know…
    • Q: How many synapses are in the human body?
    • A: A LOT. In the brain alone, there are approximately 100 billion neurons and each of them has the capability to make thousands or 10s of thousands of connections with neighboring cells, so the number is probably in the 100s of trillions or more (if you include the brain, spinal cord, and peripheral nervous system.) The 100 trillion synapses of the brain go a long way…even though computers currently have the ability to be faster than the human brain, they don’t even come close to matching the storing power or complexity of the human brain.

Nervous System Part I: Neurons

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Neuron Function 0:06
    • Basic Cell of the Nervous System
    • Sensory Reception
    • Motor Stimulation
    • Processing
    • Form = Function
  • Neuron Anatomy 1:47
    • Cell Body
    • Dendrites
    • Axon Hillock
    • Axon
    • Axolemma
    • Myelin Sheaths
    • Nodes of Ranvier
    • Axon Terminals
    • Synaptic Vesicles
    • Synapse
  • Neuron Varieties 9:04
    • Forms of Neurons Can Vary Greatly
    • Examples
  • Action Potentials 10:57
    • Electrical Changes Along a Neuron Membrane That Allow Signaling to Occur
    • Na+ / K+ Channels
    • Threshold
    • Like an 'Electric Wave'
  • A Neuron At Rest 13:56
    • Average Neuron at Rest Has a Potential of -70 mV
    • Lots of Na+ Outside
    • Lots of K+ Inside
  • Action Potential Steps 16:37
    • Threshold Reached
    • Depolarization
    • Repolarization
    • Hyperpolarization
    • Back to Resting Potential
  • Action Potential Depiction 21:38
    • Intracellular Space
    • Extracellular Space
  • Saltatory Conduction 22:41
    • Myelinated Neurons
    • Propagation is Key to Spreading Signal
    • Leads to the Axon Terminals
  • Synapses and Neurotransmitters 24:59
    • Definition of Synapse
    • Definition of Neurotransmitters
    • Example
  • Neurotransmitter Function Across a Synapse 27:19
    • Action Potential Depolarizes Synaptic Knob
    • Calcium Enters Synaptic Cleft to Trigger Vesicles to Fuse with Membrane
    • Ach Binds to Receptors on the Postsynaptic Membrane
    • Inevitable the Ach is Broken Down by Acetylcholinesterase
  • Inhibition vs. Excitation 30:44
    • Neurotransmitters Have an Inhibitory or Excitatory Effect
    • Sum of Two or More Neurotransmitters in an Area Dictates Result
    • Example
  • Neurotransmitter Examples 34:18
    • Norepinephrine
    • Dopamine
    • Serotonin
    • Endorphins

Transcription: Nervous System Part I: Neurons

Hi and welcome back to www.educator.com.0000

This is the first lesson on the nervous systems and this is about neurons.0002

Neurons are the basic cell of the nervous system.0006

The brain alone has a hundred billion neurons.0009

Besides the brain, you have the spinal cord and the other nerves.0013

You got billions of neurons in your body.0017

About 25% of your neurons are concentrated on your brain alone.0020

There is a lot of going on there.0026

There are 3 basic functions for us to summarize.0028

The first one is the sensory reception.0031

Those are the neurons that are receiving in what your body is experiencing outside of your body.0034

What your neurons notice within your body, they can sense that and tell your brain.0040

Besides you got the other direction, the motor stimulation.0046

The motor stimulation, it is going from the brain, spinal cord, out.0050

That controls your muscles, glands, organs, all stuff.0052

Any action your body does is controlled by neuron and that is motor stimulation.0060

Processing, these are the in between neurons.0066

You have a sensory signal going from the central nervous system, you have intraneurons.0070

It is the one connecting the sensory to the motor going back out.0077

That is the processing portion.0081

In your cerebral cortex, there is a lot of processing going on.0084

The form = function this is any much tissue of the body, whatever it looks like that corresponds to whatever function they have.0092

You are going to see that in the next slide.0104

This neuron is a classic looking neuron.0106

This is your typical form for a typical function of a neuron.0110

You have up here the receiving end of the neuron and you have here the end that is sending the signal to whatever cell is beyond it.0116

It could be another neuron or muscle cell or sweat gland.0126

When we look at the basic neuron anatomy, there are few parts you have to keep in mind.0131

The cell body is this part right up here.0137

The cell body is where you have most of the organelles that you see in a typical cell.0142

This green dot is the nucleus.0146

You can see ribosomes, mitochondria, etc.0149

The dendrites look like little tree branches.0153

The little tiny extensions extending beyond it you can call it dendritic branches.0157

Those dendritic branches they are on the receiving end.0169

They have a signal molecule that docks there and then initiates the signal into the neuron as a whole.0173

The axon hillock is the connection portion between the cell body of the neuron and the axon.0179

Right here that is a thicken portion that connects the cell body and the axon.0190

The axon is this classic long part.0196

I am drawing a purple line through those yellow sheets.0202

The axon is typically long for sending the electrical signal to some other part of the nervous system.0207

The axolemma on the axon is basically the modified plasma membrane.0216

If you are going to zoom in this purple part here that border you can call the axolemma.0224

And lemma means sheets or husk.0231

It is like a husk of a corn that surrounding that axon.0236

Lemma means husk.0241

Axolemma border of the axon.0244

Myelin sheets, these yellow wrappings are made up of myelin.0246

Myelin is 80% lipids and 20% proteins.0253

It is mostly fatty when we look at the structure of it.0257

The nickname of it is in the peripheral nervous system is Schwann cells.0261

Each of these is its own separate cell.0268

The orange dot is the nucleus of each one and they are made up of myelin.0272

Picture that my arm here is the neuron.0277

Here you got the cell body, dendrites with the dendritic branches.0279

Here is the axon.0283

Imagine that they are socks wrapped around my arm, the socks wrapped around my forearm here would be the myelin sheets.0284

The function of these, we will get into that more in the future.0296

It has to do with insulation and increasing the speed of electrical conduction.0300

Nodes of ranvier are here.0307

They are parts of the axon that are exposed.0313

Right here you have a Schwann cell that is covering the part of the axon but in between of this two Schwann cells,0318

there is an exposed axon section that is the nodes of ranvier.0325

Axon terminals are right here.0329

Another name I have heard for the ending here are axon buttons.0337

It is the ending of the axon, the termination of the axon.0344

Here are these little axon terminals and it has neurotransmitter released from there.0352

If we were to zoom in to one of these axon terminals, concentrated at the end here you are going to see synaptic vesicles.0359

Inside of the synaptic vesicles are little signaling molecules called neurotransmitters, these little black dots.0379

What happens is when you got electric signal travelling down the axon, at the end of the axon terminals these little vesicles are waiting to be stimulated.0389

When stimulated they are then fused with the end of the axon button and end up dumping these neurotransmitters into the synapse.0398

They end up traveling to the next neuron or to whatever the neuron is affecting.0409

These synaptic vesicles hold those little neurotransmitters until they are stimulated and they are usually calcium.0417

The synapse is the space.0427

Right where I drew the little black dots, those are the synapse.0430

The synapses there are 2 main varieties.0434

One of them is the electrical synapse0436

Electric synapse would be if this is the axon terminal of one neuron here is the cell body of the next.0439

If they are physically attached to each other by protein there is no space in the synapse.0449

It is just the connection of the two.0454

If this is the one that is sending the signal this is the pre synaptic neuron and this is the post synaptic neuron.0457

The way that they stimulate each other is just simply electrical signal from the axons of these stimulates this one.0464

That is not as common in the nervous system.0472

What tends to be more common is here is the endings of the axon and here is the cell body of the next one,0474

there is a space between the pre synaptic and post synaptic neurons.0480

That space is called chemical synapse.0487

It is chemical synapse because the chemicals found in it are these neurotransmitters, these little black dots that I have mentioned before.0490

If you were looking at a chemical synapse here you might see something like this.0497

Here is the cell body of the post synaptic neuron, little dendritic branches coming out and you can see that there are little spaces in here.0504

That is the synapse.0516

The amazing thing is some neurons have thousand of synapses with neighboring neurons.0518

If you consider all those different connections, the potential for those connections in the brain,0526

you can see how a hundred billions of neurons can give you a lot of variety in terms of the neural pathways.0531

A hundred billion neurons times a thousands of synapses, it is amazing to think about.0537

Like I said the form = function.0543

The forms of neurons can vary greatly.0547

Here are some examples.0550

This one here on the far left, this is a classic looking neuron from the cerebellum.0552

If you take slices through the back of the brain the cerebellum, when you look at a microscopic level you have these amazing sets of dendritic branches.0559

It looks like a crowded tree with tiny little branches all through out.0573

This shows you that you can have all kinds of signals coming up to this.0577

There are so much on the receiving end.0585

Here is the cell body down here and there is the axon.0587

This is part of the cerebral cortex, the outside of the brain.0592

This is a simpler, average looking neuron.0596

Here is the cell body, dendrites, axons, and axon terminals.0600

Looking back at the human brain, here is how you are able to smell, odoring molecules or smell odors would drift here,0606

stimulate these particular neurons and you have a relay station here, mitrocells assisting in getting the signals into these fibers.0619

These are extension of neurons especially axon portions that when come together to be olfactory nerves0629

which is just giant bundle of axons located up there that allow you to smell.0638

These are just 3 examples and there are a lot more.0644

Neurons can vary in their form based on the functions that is needed.0648

Action potential describes how electric signal is transmitted along the neurons.0653

How does it get from the dendrites connected to the cell body, down the axon to the axon terminals?0667

How does it happen?0674

It is action potentials.0675

These are electric changes along the neurons membrane that allows signaling to occur.0676

The 2 main contributors are Na+ and K+ also known as sodium and potassium.0681

These are both charged ions, both known as cations.0687

They are both big players in how these little electrical waves occur.0693

It is all or none activity meaning you cannot have stimulates a neuron.0699

You are either stimulating it or not?0705

It is at rest or it is sending signals.0708

What you can vary is how many signals is it sending in a second?0711

Is it sending 200 signals?0716

Is it sending 1 or 2?0718

This is a little graph that depicts what happens in an action potential.0719

Typically the average neuron is at rest when it is -700725

This is in millivolts.0729

A -70 the neuron is just chilling.0733

You can see here that there is a failed initiation meaning there is a tiny bit of a signal from a neighboring neuron0736

maybe a few neurotransmitters that dock but not enough to get it going.0743

You can see that there is a little hump but it not go all the way.0747

Once you reach threshold that is the level when it its going to happen.0751

Once you reach threshold it is going.0756

Threshold at -55 you are going to get depolarization.0759

Depolarization is where it gets more positive.0764

You are going to see in the next few slides how that happen.0767

Basically a lot of sodium enters the cell and gets it all the way to +40.0769

Some textbook says +30 but if you are using textbook where you are learning from me, please follow along whatever the textbook says.0776

I have seen textbook says +30 and I have seen other say +40 as this little graph does.0784

Following depolarization, it goes back down to where it came from repolarization.0790

The opposite occurs, instead of a bunch of positive of sodium coming into the axon, potassium leaves.0795

When that positive ions leaves, brings it back down to negative.0803

Enough of it leaves to get it back below what was the original resting potential goes down to about -90 and comes back to resting.0807

You can see that if you look at the time this is in milliseconds.0818

In just a few milliseconds is one action potential.0822

Think about of how many you can get in a second of time.0825

Like I have said it is an electrical wave.0828

You will see that in the next few images that I will show you.0831

A neuron at rest, the average neurons have a potential of about -70 millivolts at rest.0836

More negative ions are inside of the axon than in the outside0842

The reason why it is important to realize is because that is why it is -70.0846

This is an axon, pretend this is an axon without myelin sheets.0854

That exist, there are lots of axons in the nervous system where we are not going to see those wrappings.0865

It is just a pure, bare axon from the cell body over the terminals.0870

In other areas that you are going to see those wrappings.0877

Let us pretend we are not looking at those wrappings right now.0880

This is just the axolemma and these are little proteins.0882

Gauged protein channels which me may have learned in biology.0888

They involve transport of ions back and forth and usually it is involving ATP to do that.0893

To start off it is more negative.0900

I am going to draw negative signs here on the inside of the axon.0904

Here this is the intercellular part and here is extracellular side.0908

I could draw a few negatives here because there are going to be negative ions.0930

There are 4 charged ions, there are chlorine ions, etc.0935

Definitely a lot more on the inside.0939

How you get the -70 millivolts.0941

When we look at the amount of sodium and potassium, you can see a lot more sodium outside.0943

Like I said earlier, the way you get that negative depolarization is because a lot of sodium is coming in.0951

I am going to draw a gigantic Na+ here and I am going to write a tiny Na+ on the inside.0955

You are going to get some sodium on the inside of the axon but proportionally concentration wise you are going to have a lot more inside.0964

Conversely there is a lot K+ on the inside.0972

I am going to draw a tiny K+ on the outside just to show you there is some there but this is where they are most abundant when a neuron is at rest.0979

Keep that in mind when we talk about how action potential is initiated and what happens next.0990

Here are the steps on how you get action potential coming to perish on.0996

Here is going to be our graph.1002

I know that people who are in the math will be bugged by the fact that I am doing this but just bare with me.1006

I am going to draw -70 millivolts above the x axis, normally negative number would be below but for the sake of this example it is better this way.1013

Our range is from -70 to +30.1030

Resting potential is right here.1036

Here is time in milliseconds and this is millivolts on the y axis.1039

Those are our milliseconds.1047

Here is our neuron specifically on the axon.1053

This is a 3 dimensional structure but we are looking at 2 dimensional here but1061

the picture that you are going to see on how this works is 2 dimensional so bare with me.1071

Threshold reach, as we look before with the cell body, threshold all it takes is getting enough of the situation to dock at the dendrites,1076

to have the electrical signal be initiated to the axon.1087

That is going to get you up to -55 approximately and you are going to go from there.1091

Imagine that just to the left of the image here you got the axon hillock, cell body, and there are enough of signals docking here and get it going.1096

Depolarization we are going to use red to depict depolarization.1108

That is sodium moving inwards from the extracellular space.1113

That is depolarization in red.1119

That is when you have a whole bunch of sodium going in.1126

It is started with negative millivoltage on the inside.1132

Once a bunch of positives come in, your net charge will be more positive.1138

It is going to go until you get +30.1144

If you are asking what if it just goes to +10?1146

It is regulated in a way where it is going to go all the way up to that.1149

It is predictable how much sodium goes in to get it to that point.1153

Once depolarization finishes, this little sodium channels once you get it to +40 they are going to deactivate.1158

They are going to close.1167

That is going to initiate the other one, the potassium ones to open.1169

Let us use blue for the potassium part of it that is known as the repolarization.1173

Repolarization is going to get you all the way down there.1179

We have a bunch of potassium inside, once this happens you get a bunch of that Na+ inside that is going to trigger a bunch of potassium ions to leave.1184

One thing to keep in mind, this is just action potential for just this part of the axon.1202

The action potential is to initiate another action potential and another action potential.1209

That is why it is good to picture it as an electrical wave.1215

The electrical wave finishes here and initiates at the next one.1217

Once you have repolarization happening here you are going to start off to get that threshold being reached at the next one1222

and depolarization is going to happen right after it.1230

It is nice to think of it as a wave because it happens up and down the next place.1233

Hypopolarization is when you have slight more positive leaving the inside of the axon then you need to have to get pass -70 millivolts.1239

It goes down a little further to -70 about to -90.1255

Then it evens out again, you get back to resting.1262

Those little switching happens where you get going back to resting so that right away it is ready again to be stimulated.1268

You can have hundreds of action potentials happen in just a second or two.1278

It is amazing to think about.1283

Resting, depolarization, repolarization going back down, hypopolarization, back to resting potential.1284

Here is another image that shows this.1296

Here is the intercellular space and here is the extracellular space, you can see that initially the sodium is coming in.1302

These little orange hexagons are coming into this little area here that fits them and that dumps them on the inside.1314

What are these little purple things?1326

Those have to do with ATP.1328

It have to do with using ATP to power these little protein channels.1330

The potassium does the exact opposite.1335

Potassium is going to end up leaving.1338

You could see that this little yellow ovals come in here and that are dumped out.1341

You see that because of the action potential you have the increase of sodium here and increase of potassium in the opposite direction.1347

That is how you get that up and down of depolarization and repolarization.1356

Saltatory conduction that terms come from the Spanish word salta meaning to jump.1360

Saltatory conduction is the jumping in electrical signal in axon.1369

This happens every second of everyday in your life in your body.1373

Anywhere you have an axon that is covered by Schwann cells or the other one is oligodendricytes.1377

Oligodendricytes tend to be more in the central nervous system, the brain and spinal cord.1384

In some parts of your peripheral nervous system you have this Schwann cells.1391

Whether you are in the brain, spinal cord, or nerves going through out your body you are going to see these little sheets,1396

this little covering around the axon.1402

Think of it this way, if you have those little wrappings what it does is1404

instead of the electrical signal the action potential having to go along every little portion of the axon.1412

If I have a wrapping and here, you have those little nodes of ranvier1419

and salutatory conduction means the action potential jumps from node to node and that speeds up the signal.1425

Another function of this is just insulation.1434

It is a protection and insulating of the axon.1437

Primarily that jumping is going to speed up the electrical signal.1440

That is very important.1445

Saltatory conduction you get that jumping of the electrical signal all the way to the axon1446

until you inevitably get to the axon terminals where you have synaptic vesicles waiting.1452

They are waiting to get that signal to the next neuron or whatever is right after that pre synaptic neuron.1457

I love this image because they are showing how oligodendricyte covers these axons on some neuron within the central nervous system.1462

They are showing you what it looks like on the inside of the axon.1471

It easy to forget that there are intracellular things beside just charged particles like sodium and potassium.1475

Here they are showing you they have micro tubule and micro filament.1482

If you remember from biology those are important parts of the cyto skeleton.1486

The cyto skeleton you are going to find that in a specialized modified cell like a neuron.1490

Synapse and neurotransmitters.1497

Like we have mentioned before synapses are the spaces between neurons or a neuron and whatever after that synapse.1502

Neurotransmitters are molecules that drift across synapses.1511

That is the case in chemical synapses when they are right on each other.1516

More often you are going to have a tiny space between a pre synaptic and post synaptic neuron.1522

This is s great picture of it.1528

Here is that little button at the end of an axon terminal.1529

One here that would be action terminal.1534

Two this is a modified plasma membrane of a muscle called sarcolemma.1536

Three, is a synaptic vesicle.1544

If we zoom into that, what is inside of that vesicles are tiny neurotransmitters.1549

There are a lot of different neurotransmitters in your body and they have slightly different functions and rules.1557

In this particular example we are going to talk about acetylcholine also abbreviated as ACH.1564

That is a classic abbreviation for acetylcholine.1571

It has very important function is the central nervous system.1574

Here we are going to talk about the peripheral nervous system.1577

What does it do to your arms, torso, legs?1580

When you have this nerve coming off your spinal cord and going to your muscle, you are going to have ACH being that initiator.1584

If you ever wonder what makes my muscle contract?1592

ACH is that signal that goes form the neurons to the muscles to actually make it contract.1595

These little things here these are receptors that have perfect fit for ACH.1602

ACH is like a key that fits into the lock.1611

Number 4, without ACH fitting there it is not going to stimulate the muscle.1614

Number 5, is labeling a mitochondrion.1620

How would ACH actually leaves a neuron and go toward to its destination and how would it function?1623

Here is the answer.1637

If you look at these how this neurotransmitters functions and how they move across a synapse, there are 4 steps.1638

Number 1, action potential depolarizes synaptic knob.1647

This synaptic knob I have been calling it axon button.1651

It is the same basic thing.1655

Action potential, you are going to get action potential happening all the way down the axon to the end here like a wave of electricity1657

and that is going to cause calcium also labeled as Ca2+ because it is a charged ion, it has +2 charge unlike Na and K that have +1 charge.1664

Calcium is not just in your bones.1682

It is not just for giving your bones all that matrix and hardness that gives them most of their mass.1684

Calcium is also very important in making neurotransmitters drift across a synapse.1692

Once you have that wave electricity down here it stimulates calcium to move these little synaptic vesicles to the edge1697

and it causes them to fuse with the edge and dumped through exocytosis, the little transmitters in that synapse.1708

They just drift across through passive transport.1718

I do not want you to think that ATP is forcing them across.1720

The synapse is very tiny and all it takes is just a bunch of diffusion and drifting of these neurotransmitters across.1725

Those little black dots are going to symbolize the neurotransmitters and they are going to dock to those little receptors.1735

Next up ACH binds those receptors on the post synaptic membrane like I have demonstrated in the previous drawing.1746

Once those little black dots come into contact here and this is definitely not doing this just 6, you only see just 7 of this little protein receiving the neurotransmitters.1755

There are going to be hundreds, probably thousands on the average motor end plate,1770

which means you have a motor signal coming to that muscle and you have the reception of that signal there that end plate.1778

Once the ACH binds to those receptors that ACH is going to initiate muscle contractions.1786

In future lessons you are going to learn about how a muscle contracts once that signal is received.1793

You got to get of ACH to stop the initiation of the muscle contraction.1799

If ACH stays there contraction is going to keep happening.1804

You want to get rid of it eventually.1807

A lot of times there is an enzyme hanging there and ready to be used when you want to get rid of that signal.1809

In this case, it is called acetyl cholinesterase and it gets rid of those little black dots, which is ACH and once that is broken down the signal stops.1816

If you want it to be happening again dump more ACH out of that little synaptic knob or axon button.1833

That is how neurotransmitters functions across a synapse.1840

When it comes to one neuron stimulating another it has a lot to do with inhibition and excitation.1843

Inhibition is the turning of the signal and making neuron stop doing what it is meant to do.1852

Excitation is the exact opposite.1857

It makes those action potentials happen more and more.1860

Neurotransmitters some of them can do both depending on where they are located.1863

Some neurotransmitters are only inhibitory and others are only excitatory.1867

The sum of 2 or more neurotransmitters in an area dictates the result.1872

Here is an example of that.1877

We are going to talk about pre synaptic inhibition first.1879

Let us say this is pre synaptic neuron that is going to stimulate this neuron here.1882

This will be called post synaptic neuron1896

and it is going to have little dendritic branches that is going to increase the reception of the signal and here is the synapse.1899

What you can have here is another neuron off to the side that can affect whether or not this pre synaptic neuron is going to send the signal across.1908

Let us say you got action potentials going along here and all you need is calcium to make these little synaptic vesicles dump their neurotransmitters across.1921

You can have this particular neuron send signals here to turn off this process.1936

If you have this ability here for these neurotransmitters to prevent calcium for making this fuse and make exocytosis that is called inhibition.1948

You are not going to get neurotransmitters dock in here on the post synaptic neuron.1958

That means you are turning off the ability of this neuron to effectively stimulate this one.1966

The opposite can be true.1972

You can actually have pre synaptic facilitation which is a form of exciting this particular neuron.1975

The opposite can happen.1986

We can have a lot of neurotransmitters coming from this particular synaptic knob1987

or axon button getting this stimulated and causing these synaptic vesicles to fuse there1995

by dumping the little neurotransmitters here and docking on these little proteins on the receiving end.2007

That would cause the electrical stimulation and the action potentials to carry along this particular neuron.2017

You have both sides of those and it is into summation.2025

If I have one little neuron here and one neuron here and this one is producing an inhibitory effect and this one is producing excitatory or facilitating effect.2028

Whichever won is doing more is going to win.2040

If you have significantly more inhibition coming from here than excitation from here chances are2044

this particular neuron is not going to be throwing enough neurotransmitters over here to initiate action potentials.2049

Here are some examples of neurotransmitters.2056

There are a lot of neurotransmitters in the nervous system and here are some of the main ones.2060

Norepinephrine also known as noradrenaline and you also have epinephrine known as adrenaline.2065

This is a very common neurotransmitter that you are going to see in the nervous system.2071

It is typically excitatory.2077

It is similar to how ACH is in the nervous system.2078

Remember ACH stimulates muscles to contract2083

Norepinephrine does a lot in the brain to stimulate neuropathways.2086

Dopamine depending to where it is and what part of the brain it is in, it can be excitatory and inhibitory.2091

Here are 2 examples.2098

In terms of how it is inhibitory, in some regions it prevents over stimulation of muscle.2100

It prevents you from doing too much muscular contraction you are not supposed to.2108

If I lay my arms down in this table, I am contracting my triceps brachia to bring my arms down like this.2113

I have stopped my biceps brachia from contracting and they are more relaxed.2124

If I did not have dopamine working with my nerves that are going to my arms I can have a shaking going on.2131

A lot of research in Parkinson’s disease has verified that dopamine plays a role.2140

If you do not have dopamine in certain parts of the brain working effectively, you can have a shaking going on.2145

Where the person does not have as much control as they have used to in terms of extending and arm in a particular way and bringing it in when they want to.2152

That dopamine imbalance has to do with Parkinson’s.2160

In other regions, dopamine can give the brain a sense of reward.2165

This will be on the excitatory side.2169

In other parts of the brain, they do not have to do with muscle control,2171

the time you feel most proud of something you have done like a natural high you get from accomplishing something, thank dopamine.2176

There are times when a drug can give your brain illusion of having a lot more dopamine inside of the brain.2184

That is how cocaine works.2192

Cocaine that particular drug when it is snorted the chemical going to your brain is called dopamine reuptake inhibitor.2194

It means it keeps dopamine in the synapses much longer than it is supposed to.2205

If you do not get rid of dopamine it is going to keep making those neuro pathways activated.2210

Like I have said before, if you get rid of a neurotransmitter like with acetyl cholinesterase breaking down ACH2216

that is one way of getting rid of it but you can also suck them back up.2223

That is called reuptake.2227

If you get dopamine back in the neurons where it is supposed to be when you stop it signaling2228

that is one way to stop it but something like cocaine it is going to prevent the reuptake.2234

It is going docking longer and it gives you artificial sense of happiness, pride, or having a great feeling.2240

That is a part of high of cocaine there are negative aspects of doing that.2248

Serotonin that is an excitatory one.2253

This affects attention and emotion.2256

There are a lot of anti depressant drugs that act upon serotonin.2258

If you are having a serotonin imbalance maybe not enough being let go into your brain or too much2263

that can affect your ability to have your attention focus on something and can affect your mood.2272

Endorphins are those natural transmitters that inhibit pain.2279

When I broke my collar bone in high school, there is a period of time right after breaking it, I did not feel any pain and it is called shock.2285

I was walking around for 20 or 30 minutes with this numbness and my brain is attempting to protect me from feeling all that intense pain from this bone being fractured.2295

It eventually wore off and I have felt the pain later.2307

Endorphins are also interesting when talking about opiates.2310

Opiates being class of drugs, opium, morphine, heroin,2314

These drugs if you look at the active ingredient it mimic the shape of endorphins.2320

If you ever wondered make morphine makes someone in the hospital feel like they are on cloud 9.2327

How it happens is if endorphins are the natural neurotransmitters that make you feel that you do not have pain.2333

Somebody who has an intense surgery or a burn victim, somebody who is an AIDS patient or maybe going through a lot of pain,2342

you want to give them more endorphins that their body willing to dish out.2350

Having morphine drifts intravenously that morphine going to the brain it is like the brain having more endorphins than it naturally have.2355

You are going to prevent that person from experiencing pain they would have experienced otherwise.2365

Somebody who is completely healthy and in no need of morphine they can get easily addicted to it.2370

The more you introduce morphine to your system the more the cells your brain make little receptors to respond to that additional morphine.2378

That is how addiction eventually builds and builds.2387

With addiction you are going to get withdraw all the symptoms if all of a sudden you stop introducing that morphine into your body.2391

Drugs are not something you want to play with.2397

Stick with your natural supplies of neurotransmitter whenever possible.2400

Thank you for watching www.educator.com.2405

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