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126 terms

bio132 chapter 19

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what are the cheif functions of the digestive system
digestion, absorption, and elimination
what are the 4 layers of the digestive tract
mucous membrane, submucosa, smooth muscle, serous membrane
what is the function of the mucous membrane
secretes digestive juices and mucus
what is the submucosa made of and wht is its funtion
made of connective tissue. I t contains blood vessels and nerves that help regulate digestion
what are the 2 types of smuscle in the smooth muscle layer and what is its function
innler layer is circular outer layer is longitudinal. Its function is peristalsis.
what is the serous membrane (peritoneum) made of
epithelium and loose connective tissue.
what are the 2 ;ayers of ther peritoneum
viseral and parietal
what are the the organs of the digestive tract
mouth, pharynx, esophagus, stomach, small intestine, large intestine
how does the mouth process food
ingestion, mastication, mixing with saliva, deglutition
what is the digestive enzyme in the outh and what does it digest
amylase digests startch
how many deciduous (baby teeth) do we have
20
how many aldult permanent teeth
32
what are the different types of teeth
incisors, cuspids, molars
what is the structure of teeth
dentin, blood vessels, nerves, gingiva, crown, enamel, roots
what is the tissue in the mouth
startified sqamous epithelium
what is the pharynx also called
throat
what are the srtuctures of the pharynx
oropharynx, palatine tonsils, nasopharynx, laryngeal pharynx, soft palate, uvula, epiglottis
what is the esophagus
a muscular tube that joins the mouth to the stomach, by moving food by perastalsis. Do digestion occurs in the esophagus
what is the esophogeal hiatus
a break in the diaphragm through which the esophagus passes through
what structure guards the endtrance to the trachea during swallowing
epiglottis
what is the structure of the stomach
it has an additional angled muscle layer, fundus, lower esophogeal sphincter, pyloris, pyloric sphincter, rugae
what are the functions of the stomach
store food and liquid, secrete gastric juice, secrete mucus, makes chyme
what is chyme
highly acidic mixture of gastric juice and food that leaves the stomach for the small intestine
what type of food is digested in the stomach
protein only
what are the 3 sections of the small intestine in order
duodenum, jejunum, iliem
what enters though the duodenum
juices from liver and pancreas
how long is the small intesting
10 feet
what is the function of the small intestine
secrete mucus, secrete enzymes, absorb digested food
at what part of the small intestine is food absorbed
jejunum, iliem
what is the tissue of the small intestine
simple columnar epithelium
what surface projections increase surface are and absorbs the small molecules
villi, microvilli which have blood vessels and lymphatic capillaries (lacteals)
what carries fat away from the small intestine
lacteals
what is the structure of the large intestine
cecum, ileocecal valve, vermifor appendix, colon, rectum, anal canal, anus
where does the small intestine join the lg intestine
cecum
what are the divisions of the colon
ascending, transverse, descending, sigmoid
what is the function of the large intestine
secrete mucus, reabsorb some water, form feces, defecation
what is the function of the accessory organs
release secretions through ducts into digestive tract
what is the accessory organ to the mouth
salivary glands
what are accessory organs to the duodenum
liver and pancreas
what is the function of saliva
moistens food, facilitates mastication, helps keep teeth and mouth clean, contains amylase
where is saliva produced
parotid glands, submandibular glands, sublingual glands
what is the structure of the liver
right and left lobes, portal vein, hepatic artery
what is the function of the portal vein
takes blood from the GI tract to the liver
what is the function of the hepatic artery
carries O2 blood
what are the functions of the liver
manufacture bile, store glycogen and converts it to glucose, modify fats, store vitamins and iron, form blood plasma proteins, destroy rbc, synthesize urea, detoxify harmful substances
what does bile contain
cholesterol and bilifuben
what is the function of bile
to emulisfy fat
where does bilirubin come from
destroyed rbc
what is urea
waste product
where is bile stored, how does it ge there
stored in the gall bladder, flows from liver through cystic duct.
how does bile leave the gall bladder when it is needed
flows through cystic duct anc common bile duct to the duodenum
what is the function of the pancreas
releases enzymes that digest fats, proteins, carbohydrates and nucleic acids, produces alkaline fluid to neutralize acidic chyme in the small intestine, produces insulin and glucagon
Where is the pancreas locates
behind the stomach
what is the exocrine functon of the pancreas
produce pacnreatic juice
what cells secrete enzymes in the pancreas
Acinar cells
what are the 3 enzymes the pancrease secreates and what does each one digest
amylase-starch, trypsin-protein, lypase-tryglcerides
where does the most chemical digestion occur
duodenum
what secrete enzymes for digestion
salivary glands, stomach, sm and lg intestine, liver, pancrease
what is the force behin chimal digestion
enzymes
what does the gi tract use fluids for
to lubricare, liquify and digest food
what is the function of mucus in digestion
to lubricate food, protects the lyning form chemical or mechanical injury
what is the function of water in digestion
liquifies food making it easier to digest and to absorb, it acts as a solvent that allows electrolytes to move across the intestinal wall
what parts of the stomach act as storage
the fundus and the body
what area of the stomach is primarily responsible for digestion
pyloris
what type of digestion occurs in the stomach
mechanical chemical
what does the combination of food, gastric juice and water that is formed by the stomach called
chyme
what are the 2 cells in the stomach
cheif and parietal
what is the fuction of cheif cells
secretes pepsinogen and gastric lipase
what is pepsinogen
inactive form of pepsin which is needed to preak down proteins
what is gastric lipase
enzyme that preaks down milk fat
what is the function of parietal cellls
secrete HCL, and instrinsic factor
what is the function of HCL
activates pepsinogen, and kills most microorganisms
what is cholectstokinin CCK
a hormone secreted by the duodenum and jejunum in the small intestine in response to fat enetering the duodenum. It activates the gall bladder to release bile which will flow throught the cystic duct into the common bile duct to deposit it in the duodenum
what does CCK stimulate the pancrease to do
it stimulates the release of pancreatic juice and pancreatic digestive enzymes which are then changed to active form in the small intestine.
what is in thepancreatic juice and what is its function
bicarbonate which will neutralize the chyme
what enzymes are released from the pancrease and what to they digest
trypsin-protein, lipase-fats, amylase-startch
what absorbs fatty acid in the sm intestine
lacteals in the villi
where does fat go after it is absorbed by the lacteals
liver
what are lacteals part of
lymphatic system
what absorbs sugar, amino acids and water?
capillaries in the villi
what is aborbed in the lg intestine
water, electolytes,
where are water soluable vitamins absorbed
directly into theblood
where are fat soluable vitamins absorbed
absorbed with fats
what is produced by bacterial action in the large intestine
Vitamin K
what are the 2 types of control for the digestive system
hormonal and nervous
what does the parasympathetic nervous system stimulate in the digestive system
stimulation increases activity
what does the stimulation of the sympathetic nervous system do for the digestive system
decreases activity
what are the hormones produced during digestion
gastrin, gastric inhibitory peptide, secretin, cholecystokinin
where is gastrin secreted and what is its function
produced by the stomah stimulates the release of gastric juice
where is gastric inhibitory peptide secreted and what is its function
produced by the duodenum and stimulats insulin release from the pancreas when glucose enters the duodenum, inhibits gastric juice
where is secretin produced and what is its function
produced by the duodenum, It stimulates the release of water and bicarbonate from the pancreas, stimulates the release of bile from the liver, inhibits the stomach
where is cholecystokinin produced and what is its function
stimulates the release of digestive enzymes from the pancreas, stimulates the release of bile from the gall bladder, inhibits the stomach
what regulates hunger
hypothalamus
what stimulates the hypothalamus
blood nutrient levels
what satifies hunger
an adequate meal
what is appetite
no relationship to need for food, may not be satifidfied by an adequat meal.
what is leptin
a hormone produced by adipose tissue that is involved in weight regulation
what are the sources of digestive problems
mechanical, nervous, chemical, horomonal, infection
what are some diseases of the mouth and teeth
dental carries, gingivitis, periodontitis, vinvent disease, leukoplakia
what is periodontitis
infection of the gum and teeths supporting bone
what is vincent disease
gingivitis causes by bacillus or spirochete and can cause death to the tissues
what is leukoplakia
Pre cancerous thickened white particles on the mucous membranes common in smokers
what carries blood fromthe digestive tract to the liver
portal vein
what is gastritis
inflammation of the linning of the stomach
what is a pyloric stenosis
obstruction of the pyloric sphincter
what are causes of inflammatory bowel disealse
crohns and ulcerative colitis
what does crohns disease effect
small intestine
what does ulcerative colitis effect
large intestine
what is gastroenteritis
infection of stomach and small intestine
what is mumps
contagious viral infection of the parotid salivary glands
what are possible complications of mumps
inflammation of testicles, sterility in males
what happens in liver cirrhosis
the active liver cells are replaced by scar tissue
what is the most common cause of liver cirrhosis
etoh
what is cholelithiases
gallstone
what is the most common gall bladder disease
cholelithiases
what happens in pancreatitis
pancreatic enzymes back up into the pancreas can be fatal
what can cause pancreatits
gall stones, etoh
what are some effects of aging on the gi system
loss of appetite, difficulty swallowing, decreased digestive organ activity, digestive disorders, tumors and cancer
what is the action of amylase and where is it found
digests starch and is found in the salivary glands and pancreas
what is the action of HCL
breaks down proteins
what is the action of Pepsin and where is it found
begins protein digestion found inthe stomach
what is the action of petidase and where is it found
digests proteins to amino acids found in the small intestine
what is the action of lactase, maltase and sucrase and where is it found
digests disaccharides to monosaccharides found in sm intestine
what is the action of trypsin and where is it found
digests proteins to amino acids found in the pancreas
what is the action of lipase and where is it found
digests fats to fatty acids and glycerol found in the pancreas
what is the action of nucleases and where is it found
digests nucleic acids found in the pancreas