Ex 38 Digestive System histology Flashcards
The digestive system:
a. Eliminates undigested food
b. provides the body with nutirents
c. Provides the body with h2o
d. All of the above
D. All of the above
(Digestion/absorption) occurs when small molecules pass through epithelial cells into the blood for distribution to the body cells
Absorption
The _____ abuts the lumen of the alimentary canal and consists of epithelium, lamina propria, and muscularis mucosae.
a. Mucosa
b. Serosa
c. Submucosa
A. Mucosa
Wavelike contractions of the digestive tract that propel food through the GI Tract is called?
Peristalsis
the ______ is located on the left side of the abdominal cavity and is hidden by the liver and diaphragm
gallbladder
true or false
Nearly all nutrient absorption takes place in the small intestine
True
Located inferior to the diaphragm, the ____ is the largest gland in the body.
Liver
What are the 4 layers surrounding the lumen of the alimentary tract?
Lumen->Mucosa->Submucosa->Muscularis externa->Serosa
What is the Mucosa and its function?
It is a wet epithelial membrane against the lumen. The main function of the mucosa are secretions of enzymes, mucus, and hormones, absorption and protection from bacteria
What is the function of submucosa?
modaretly dense connective tissue with blood, lymphatic vessels, lymphoid follicles and nerve fibers. the main function is nutrition and protection
What is the Muscularis externa and its function?
It is a bilayer of smooth muscle with the inner layer running circulary, and outer layer longitudinally.It acts as a regulator of GI motility
What is the serosa and its function?
it is the outermost layer of the alimentary canal. AKA visceral peritoneum. The serosa reduces friction as the digestive system rubs against other organs and the abd wall
What are the 3 layers of the Muscularis externa of the stomach?
Out layer: Longitudinal
Mid layer: Circular
Inner: Oblique
What do gastric glands do in the stomach?
secrete HCl and hydrolytic enzymes(pepsinogen) which break down proteins
After the food is processed in the stomach it resembles a creamy mass called?
Chyme
Chyme enters the small intestine through the ________ ________.
Pyloric sphincter
what are the cells of the gastric pit? top to bottom
Surface epithelium(mucous cells)
parietal cells
chief cells
Enteroendocrine cells
how is pepsin made?
Parietal cells release HCl and chief cells release pesinogen. These two combined make pepsin which breaks down proteins in the stomach
What are the 3 subdivisions of the small intestine?
- Duodenum
- jejunum
- ileum
at what valve does the small intestine meet the large intestine?
ileocecal valve
what 3 things in the small intestine make it more capapble of absorbing nutrients?
microvilli, villi, and circular folds create more surface area
What is the largest gland in the body?
Liver
Where does bile leave the liver? and where does it go to?
common hepatic duct to the duodenum through the bile duct
True or False
Bile has no enzymatic action but emulsifies fats.
True
When digestive activity is not occurring in the digestive tract, bile backs up into the ___ _____ and enters the __________.
cystic duct, gallbladder
what is the structural and functional unit of the liver?
lobules
what 3 structures are in the portal triad of the liver?
Bile duct, portal venule, and portal arteriole
What is the role of the gallbladder?
to store and concentrate bile
hepatic macrophages are AKA? What do they do?
Kupffer cells, removes debris like bacteria from blood.
what are the 2 endocrine hormones made by the pancreas?
insulin, glucagon
