Review Questions Flashcards
What keeps food from going down into the larynx.
The epiglottis covers the larynx when you swallow. It stays open when you breathe.
What digestive enzyme can be found in the saliva? What does it do?
Amylase is found in the saliva. It helps break down polysaccharides into smaller carbohydrates.
What does the soft palate do in deglutition?
It rises and seals off the nasal cavity during deglutition.
Starting from the outer layer and working inwards , list the tunics that are contained in most of the alimentary canal. What layer exists in the stomach?
There is the serosa/adventitia, the longitudinal muscularis, the circular muscularis, the submucosa, and the mucosa. The stomach has an extra layer deep to the circular muscularis, the oblique muscularis.
What digestive enzyme is secreted by the stomach? What does it do?
Pepsinogen is secreted by the stomach. When it hits the gastric Juice, it becomes pepsin which breaks down proteins into peptides.
Why doesn’t the acid in the gastric Juice hurt the lining of the stomach?
The gastric glands produce mucus, which coats the stomach lining and protects it from its own gastric juice
Where is intrinsic factor secreted? What does it do?
It is secreted by the gastric glands of the stomach. It binds to vitamin B12 and allows absorption of B12 by the small intestine.
What three things are absorbed through the stomach.
Water, alcohol, and aspirin.
What does the hormone gastrin do?
It increases lower esophageal sphincter tone, decreases pyloric sphincter tone, increases the rate of secretion from the gastric pits, and increases rate of mixing waves in the stomach.
What three regions of the small intestine, starting with the region closest to the stomach and ending with the region closest to the large intestine. Which region is the shortest of the three?
Duodenum, jejunum, and ileum. Shortest is duodenum.
What three design features in the intestine increase the rate at which nutrients are absorbed.
Circular folds and intestinal Vili increase surface area,. Also, cells that absorb nutrients are covered in microvilli, which increase surface area even more
List the three main hormones released by the small intestine and their effects.
Secretion: Reduces gastric juice production and increases secretion of acid-neutralizing juice from the pancreas, which increases pH of Chyme
Cholecystokinin (CCK)- causes gall bladder to contract, and increases gastric emptying and secretion of digestive enzymes from the pancreas.
Gastric inhibitory peptide (GIP)- Decreases rate at which the stomach empties.
List the major enzymes from the intestinal glands and their functions.
Maltase: Breaks down maltose
Sucrase: Breaks down sucrose
Lactase: Breaks down lactose
Peptidase: Breaks down peptides.
Enterokinase: Activates trypsinogen into trypsin
Why can’t a cell produce an active enzyme that breaks down proteins?
Producing an active protein-digesting enzyme would kill the cell.
What functions do the bacteria in the large intestine perform?
They produce vitamin K, biotin, and folic acid which are absorbed in the large intestine. They also break down other chemicals that end up in the feces.
