Module 20 - Digestive System Flashcards
why are the 2 layers of the muscularis important for digestion?
regularly contract and relax to propel food through the digestive tract
another name for the digestive tract
alimentary canal
what is the peritoneum
serous membrane lining the cavity of the abdomen and covering the abdominal organs
what is the purpose of mesentry?
suspends digestive organs within the abdominal cavity, contains blood vessels, lymph node etc, that supply the digestive organ
what is the greater omentum?
prevents friction, helps localize infection
what is the lesser omentum?
extends from the lesser curve of the stomach to the liver
what is another name for the mouth?
oral or buccal cavity
what is the lingual frenulum?
anchors the tongue to the floor of the mouth
what is the difference between the hard and soft palates?
hard palate is formed by portions of maxillae and palatine bones, it separates the mouth from the nasal cavity
soft palate consists of mostly skeletal muscle, forms an arch between the mouth and the nasopharynx
what are the names of the 2 digestive enzymes found in saliva?
amylase and lipase
how does food pass through the pharynx
tongue manipulates the bolus to the back of the oral cavity, soft palate lifts while the larynx rises and food moves through the oropharynx and laryngopharynx on its way to the esophagus
what is the primary function of the stomach?
Store food
what helps prevent backflow into the esopagus?
lower esopageal sphincter (LES)
what is the role of muscularis layer of stomach? why is there an extra layer of muscle in the stomach?
has an extra layer of oblique muscle in addition to longitudinal and circular layers.
The addition of the oblique muscle gives the muscles of the stomach wall a crisscross pattern; this allows the stomach to contract and churn vigorously as it processes food.
mucous cells
secrete mucus, protects stomach lining and keeps stomach from digesting itsefl
parietal cells
secrete hydrochloric acid and intrinsic factor. Hydrochloric acid helps kill microbes in swallowed food
Chief cells
secrete digestive enzymes such as pepsinogen
enteroendocrine cells
secretes hormone ghrelin (stimulates hypothamalus to increase appetite and gastrin (which influences digestive function)
explain the formation and movement of chyme
muscles of the stomache contract and churn to break food into small particles and to mix it with gastric juice, which results in chyme. It leaves the stomach and enters the duodenum by passing through the pyloric sphincter
what are the primary functions of the liver?
storing/releasing glucose, processing vitamins and minerals, filtering toxins, and recycling old blood cells
where is the portal vein carrying nutrient rich blood to the liver from?
from digestive organs and spleen to liver
how about the hepatic artery?
delivers oxygenated blood from the aorta to the liver
where does bile come from
liver secretes 1L of bile each day. Gallbladder stores and concentrates it
how is blood filtered?
1) nutrient-rich blood from stomach and intestine enters the lobule through small branches of the portal vein. 2)oxygen-rich blood enters the lobule through small branches of the hepatic artery. 3)blood filters through sinusoids allowing cells to remove nutrients, hormones, drugs and toxins.
what is the role of Kuppfer cells?
remove bacteria, worn-out red blood cells and debris from bloodstream
what substances does the liver secrete into the bloodstream?
clotting factors, albumin, angiotensinogen and glucose
what vein carries the processed blood out of the liver?
the central vein
what is the main purpose of the gallbladder?
stores and concentrates bile
what is the exocrine function of the pancreas?
pancreas secretes about 1.5L of pancreatic juice into the small intestine
what is the role of acinar cells?
secrete digestive enzymes in an inactive form
what is the role of duct cells?
converge on the main pancreatic duct, which joins the bile duct at the hepatopancreatic
where does segmentation occur?
at intervals along the small intestine
what is the role of bacteria found in the large intestine?
helps digest things we have no digestive enzymes for
