Digestive Physiology Flashcards
What are the two main sections of the digestive system?
alimentary canal
accessory organs
What makes up the alimentary canal?
mouth pharynx esophagus stomach intestines
What makes up the accessory structures?
liver pancreas gallbladder teeth salivary glands
What are the four main tissue layers that make up the wall of the digestive tract?
mucosa
submucosa
muscularis
serosa/adventitia
What occurs in the digestive system?
Peristalsis Segmentation Secretion Digestion Absorption Elimination
What does saliva do?
Allows food to be swallowed more easily
Contains amylase that digests carbohydrates
Contains Lysozyme that inhibits bacteria and contains IgA
Dissolves food
What does movement of the mouth and tongue and chemicals in the mouth stimulate?
Parasympathetic nervous system to increase saliva
What are the parotid glands stimulated by?
Glossopharyngeal nerve (CN IX)
What are the submandibular and sublingual glands stimulated by?
Facial nerve (CN VII)
What does the uvula and soft palate do during swallowing?
they move up to keep food and liquid out of the nasal cavity
What does the epiglottis do during swallowing?
Moves down and covers the larynx to keep food and liquid out of the air passages
What are the two sphincters of the esophagus?
Upper and Lower (cardiac)
What kinds of digestion occur in the stomach?
Mechanical, chemical (HCL), and enzymatic
What do Goblet cells in the mucosa of the stomach do?
Secrete alkaline mucous which protects the stomach from HCL
What are the Mucosal cell types?
Mucus Chief Parietal G Mark Can Pass Gas
What do the mucosal cells produce?
Mucus - Mucus Chief - Pepsinogen Parietal - HCL/Pepsin G - Gastrin Mark Passes Hot Gas
What does Gastrin do?
Increases stomach mobility & gastric gland secretion
What triggers the Cephalic phase?
Smell, taste, sight, and thought of food send signals to the medulla oblongata
What is the Cephalic phase?
The vagus nerve CN X sends signals to the gastric glands to release acetylcholine which causes gastric gland secretion to increase
What triggers the Gastric phase?
Stretching of the stomach, high pH, and peptides send signals to the medulla oblongata
What is the Gastric phase?
The vagus nerve CN X sends signals to the gastric glands and releases acetylcholine which causes gastric gland secretion to increase
What is the intestinal phase of Gastric Secretion?
Stimulated by food entering the duodenum, intestinal gastrin is released and as the duodenum is further stretched– secretin and CCK is also released
What is the Duodenum?
First section of the small intestine, secretes hormones, secretions, and bile to complete digestion
What do the Jejunum and Ileum do?
Absorb water and nutrients, the ileocecal valve regulates the movement of food into the large intestine
