test 3: digestive pt 2 Flashcards
which structure produces bile?
liver
where is bile stored?
gallbladder
what are the 3 functions of the large intestine?
1) absorbs water and electrolytes
2) absorbs vitamins produced by bacteria
3) stores feces before defecation
what are the 4 portions of the large intestine
1) ascending colon
2) transverse colon
3) descending colon
4) sigmoid colon
what is the location of the large intestine?
sits under stomach, lining almost complete ring around small intestine
-umbilical region, right and left lumbar regions, right and left iliac regions
describe the path food wastes travel through the large intestine
- ileum opens into cecum of large intestine (comes through iliocecal valve)
- ascending colon (turns 90 deg at right colic flexure)
- transverse colon (turns at left colic flexure)
- descending colon
- sigmoid colon
- rectum
- anus
what are the series of pouches that make up the large intestine called? what is their purpose?
- haustra
- allows for distention and elongation of the colon
what are teniae coli?
three separate longitudinal bands of smooth muscle
- run along the outer surfaces of colon just deep to serosa
- correspond to outer longitudinal layer in other portions of digestive tract (these create the haustra)
what is different in the histology of the small intestine that is not found in the large intestine?
villi, microvilli, or circular folds
how do the gastric glands differ from small intestine to large intestine?
gastric glands in large intestine are deeper and produce mucus
histology of the large intestine
1) mucosa (superficial)
- 3 layers
- simple columnar epithelium; transitions to stratified squamous in rectum
2) submucosa
3) muscular layer (2)
- teniae coli
- circular muscle
4) serosa
where is the location of the liver
- upper right quadrant mostly
- right hypochondriac and epigastric regions
- left hypochondriac and umbilical in some people
what are the 3 functions of the liver
1) metabolic regulation
- regulates circulating levels of carbohydrates, lipids, AAs; all blood flows through here (absorbs nutrients, wastes, toxins; through hepatic portal system)
2) hematological regulation
- 25% of blood reservoir stored here; removal of old or damaged blood cells; secretion of plasma proteins
3) production of bile
- synthesized in liver, stored in gallbladder, excreted in duodenum
how does the anterior surface of the liver differ from the posterior?
- anterior = smooth
- posterior = conforms to surroundings from stomach, small intestine, kidneys, large intestine
what divides the right and left lobes of the liver?
falciform ligament
what is the porta hepatis?
-contains hepatic portal vein, artery, and bile duct; all linked to digestive tract, not systemic circulation
how many lobes are in the anterior liver? posterior?
anterior: 2 lobes (right and left)
posterior: 4 lobes (right, left, caudate, quadrate)
what is the functional unit of the liver?
liver lobules
hepatic sinusoid - def
capillaries that surround all liver cells
-blood comes in and drains into sinusoids, drains towards central vein (veins then merge together to form hepatic vein; empty into inferior vena cava)
what makes up the portal triad?
1) interlobular bile duct
2) interlobular artery
3) interlobular vein
what is the function of hepatocytes?
- they form the liver lobules
- formation of bile
describe the movement of bile from the liver until its storage
- bile secreted into bile canaliculi
- flow from centre to periphery, forms bile ductules
- drain into nearest interlobular bile duct (portal triad)
- form into right and left hepatic ducts
- unite to form common hepatic duct
- bile sent to duodenum directly or enters cystic duct to gallbladder for storage
what type of WBC is found along the lining of sinusoids in liver lobules?
macrophages
-engulf pathogens, cell debris, damaged RBCs
what is the structure of a liver lobule?
one lobule contains one central vein surrounded by 6 portal triads in hexagonal shape
