Large Intestine and Auxiliary Organs Flashcards
why is the large intestine called “large”
diameter
4 major sections of the large intestine
cecum, colon, rectum, and anal canal
where do the small and large intestine meet
the ileocecal sphincter
cecum
- 1st portion of the large intestine
- small pouch with a projection
projection of the cecum
vermiform appendix
appendix
a reservoir for bacteria that inhabit the large intestine
longest portion of the large intestine
colon
4 major sections of colon
ascending, transverse, descending, sigmoid
rectum extends from the _______ _____ to the tip of the ______
sigmoid colon; coccyx
from the tip of the ______ it becomes the ____ _____
coccyx; anal canal
2 sphincters
external and internal
anus
the exterior portion of the anal canal
difference between the mucosa of the small intestine and large intestine
there are no villi and fewer mucosal folds than in the small intestine
cells of the large intestine
simple columnar epithelia and stratified squamos cells
how do the cells of the large intestine change
it changes from simple columnar epithelia into stratified squamos cells at the rectum and anal canal due to high mechanical stress
why does the mucosa have many goblet cells
to lubricate
large intestine functions
- recovery of water and electrolytes from chyme
- formation and storage of feces
- microbial fermentation
last __% of nutrients recovered in the large intestine
10
feces formation
70% water and 30% everything else
microbial fermentation
- provides enzymes for the breakdown of indigestible molecules (cellulose)
- synthesizes vitamins from complex molecules (K, Biotin, B5)
large intestine peristalsis
- slower but stronger contractions of teh muscularis
- 2 to 3 peristaltic waves per day
peristaltic wave
a strong contraction moving feces toward the rectum and anal sphincters
largest organ of digestion
liver
where is the liver located
upper right quadrant of the abdomen
what protects the liver
the ribs
what is the liver enclosed in
a tough fibrous capsule (continuous with the visceral peritoneum)
2 lobes of the liver
- large right lobe
- smaller left lobe
what joins the lobes of the liver together
falciform ligament (CT)
how much blood does the liver hold
1 pint
where does oxygenated blood enter the liver
hepatic artery
where does nutrient rich blood enter the liver
portal vein
lobules
functional units
how many lobules are in the lobes of the liver
100,000
liver will function normally with ________ damaged lobules
75% - 80%
liver functions (7)
- carbohydrate metabolism
- lipid metabolism
- protein metabolism
- storage
- filtration of blood
- detoxification
- secretion
carbohydrate metabolism (liver)
- polymerizes glucose to glycogen in response to insulin levels
- breaks down glycogen to glucose in response to glucagon levels
- converts non-carbs to glucose in response to glucagons
lipid metabolism (liver)
- synthesis of lipoproteins, phospholipids, and cholesterol
- conversion of carbs and proteins into fats for storage in adipose tissue
protein metabolism (liver)
- synthesis of plasma proteins especially urea, clotting factors, and vitamin K
- conversion of amino acid to other amino acids
storage (liver)
glycogen, iron, vitamins A, D, B12
filtration of blood (liver)
- removes damaged RBCs
- kupffer cells clean out debris and bacteria
detoxification (liver)
- removes toxins like alcohol
- metabolizes drugs
secretion (liver)
secretion of bile from the hepatocytes for digestion and excretion
bile
a greenish-yellow liquid secreted by the hepatocytes and stored in the gallbladder
what does bile consist of
water, bile salts, pigments (bilirubin and biliverdin), cholesterol, and electrolytes
bile
- the only active component in digestion
- emulsify fat into smaller globules increasing lipase efficiency
- aid in absorption of fatty acids and fat soluble vitamins
biliary tree flow
tiny bile ducts –> larger bile ducts –> right and left hepatic ducts –> the common hepatic duct –> common bile duct
blood flow (digestive tract to heart track)
digestive tract –> portal vein –> sinusoids –> central vein –> vena cava
blood flow to the sinusoids enriches the _______ _____
hepatic cells
gallbladder
pear-shaped sac located in a depression of the inferior surface of the right hepatic lobe
bile excretion process
- bile travels from hepatocytes to the common hepatic duct
- collects in common bile duct backing into the gallbladder for extra storage
- cck initiates a contraction of the gallbladder and the release of bile to the duodenum
gate between common bile duct and duodenum name
hepatopancreatic sphincter
gall stones creation process
- long storage of bile in the gallbladder leads to resorption of water
- concentrated bile salts and cholesterol precipitate to form stones
- stones block flow of bile causing increase pigments in the blood and pain due to blockage
does the pancreas contain endocrine or exocrine function
both
endocrine
glands that secrete hormones without ducts
exocrine
secrete hormones through ducts
exocrine pancreatic cells
pancreatic acinar cells
pancreatic acinar cells function
- produce pancreatic fluid with enzymes and buffers for digestion (pancreatic amylase, pancreatic lipases, nucleases, and proteolytic enzymes (trypsin))
- fluid flows to common pancreatic duct and joins the common bile duct at the hepatopancreatic sphincter
endocrine pancreatic cells
islets of langerhans
islets of langerhans function
- produce insulin and glucagons secreted to the blood supply
- regulate blood sugar level and the body’s energy supply
