Module 7 - Digestive System Flashcards
what is the average length of the GI tract?
5-7 meters
what is the difference between the functional and accessory structures of the digestive system?
the funtional structures come into contact with the food, this includes the mouth pharynx esophagus stomach small and large intestine. The accessory structures other then the teeth and tonge never touch the food. they are salivary glands liver gall bladder and pancreas.
what are the 6 basic processes of digestion?
ingestion, secretion, mixing and propulsion, digestion, absorption and defication.
name the 4 layers of the GI tract
Mucosa, submucosa, muscularis, serosa.
Describe the mucosa layer of the GI tract
has 3 layers, epithelium, lamina propria (connective tissue) and muscularis mucosae( has lymph nodes and folds)
describe the submucosa layer of the Gi Tract
connective tissue that holds together mucosa and muscularis. has blood and lymphatic vessels for absorption. houses nearons for ANS… enteric nervous system, brain of the gut controls secretions
describe the muscularis layer of the GI tract
skeletal in mouth pharynx and upper esophagus, smooth in GI.. circular inner and outer longitudinal. propels food.
describe the serosa (peritoneum) layer of the GI tract
secretes fluid so that Gi tract easily moves around other organs, also called the visceral peritoneum. made of simple squamoush epithelium and areolar connective tissue
what is the difference between the perietal peritoneum and the visceral peritoneum?
the perietal peritoneum lines the wall of the abdominal cavity and the visceral peritoneum covers the organs
name some things that are in the retroperitoneal
aorta, interior vena cava, duodenum, ascending and descending colons, kidneys and ureters.
what is the difference between the perietal peritoneum and the visceral peritoneum?
the perietal peritoneum lines the wall of the abdominal cavity and the visceral peritoneum covers the organs
name some things that are in the retroperitoneal
aorta, interior vena cava, duodenum, ascending and descending colons, kidneys and ureters. pancreas
what is the mesentary?
binds the small intestine to the abdominal wall
what is the Greater omentum
fatty apron over transverse colon. full of adipose tissue and lymph.
name the three salivary glands
Parotid glands, submandibular glands and the sublingual glands
saliva is made of what
99.5% water 0.5% solute
what are two enzymes in saliva and what are they for?
amylase - starts digestion of starch, lysozyme - kills bacteria
what controls secretion of saliva?
autonomic nervous system. usually parasympathetic stimulation promotes normal secretion, but under stress sympathetic takes over causing dry mouth.
what is the larynx tissue
skeletal muscle and lined by mucous membrane.
what tissue makes up the esophagus?
muscle and stratified squamus epithelium
describe the 2 esophageal sphincters
upper esophageal sphincter is made of skeletal muscle and helps food from pharynx to the esophagus. the lower esophageal sphincter also known as cardiac sphincter is made of smooth muscle and helps food from esophagus to stomach.
what is deglutition?
swallowing
what are the four main portions of the stomach?
cardia, fundas, body, pyloris
describe the stages of swollowing
voluntary - Tongue moves bolus to back of throat into oropharynx
pharyngeal stage- breathing stopes, soft palate and uvla close off nasopharynx, epiglottis closes off larynx, vocal chords close. into esophagus.
esophageal stage - circular muscles contract, then longitudinal muscles contract over and over. then down to Lower Esophageal shpincter ( cardiac sphincter) relaxes into stomach it goes
what are the three types of exocrine gland cells are in the gastric glands
muscous neck cells, cheif cells and parietal cells
what does each of the three exocrine glands in the gastic glands secrete?
mucous neck cells -mucous
Chief cells - pepsinogen
parietal cells - Hydrocloric acid (HCL)