In this lesson our instructor talks about the digestive system. First she gives an introduction to digestion and discusses types of digestive tracts. Then she talks about the human digestive system, the oral cavity, the esophagus, the stomach, the pancreas, the liver, the small intestine, and digestive enzyme. Lastly, she lectures on absorption of nutrients, the large intestine, and regulation of digestion by hormones. Four complete example videos round up this lesson.
The mouth is a site of both
mechanical and chemical digestion. The salivary glands secrete
amylase, an enzyme that hydrolyzes starch into polysaccharides and
The rhythmic contractions of
the esophagus, called peristalsis, move food into the stomach.
Gastric glands in the stomach
secrete gastric juices, which contain hydrochloric acid and pepsin.
Pepsin breaks proteins down into polypeptides.
Digestion of starches, proteins
and fats takes place in the small intestine. The pancreas secretes
bicarbonate and enzymes into the duodenum. Additional enzymes are
produced by the epithelial cells of the small intestine.
The villi and microvilli of the
small intestine provide a large surface area for the digestion and
absorption of nutrients.
The liver produces bile, which
is stored by the gall bladder and secreted into the duodenum. Bile
emulsifies fat, facilitating the breakdown of fat by lipases.
The large intestine consists of
the cecum, colon and rectum. Major functions of the large intestine
are the absorption of water and minerals and the storage of waste.
Digestion is regulated by the
hormones gastrin, secretin and cholecystokinin (CCK).
The Digestive System
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.
The book and CD package include three full length practice exams that are presented with all questions answered and explained. The author also presents detailed reviews of all test topics and includes multiple-choice and free-response questions with answers at the end of each topic's chapter.
This book has a great topic-by topic breakdown of the 14 must-know principles with sample questions and answers for each of the subjects. Laboratory Review includes a focused review of all 12 AP laboratory exercises. Included in this is 2 full length practice tests that stimulate the actual test along with answers and complete explanations.
This book includes a comprehensive biology test topic review, covering everything from photosynthesis to genetics to evolution. Cracking the AP Biology also includes testing strategies for the grid-in and essay section, great guidance on writing a high-scoring essay, and two full length practice exams with detailed explanations.