Digestive System Flashcards
what are the two groups of organs in the digestive system?
gastrointestinal tract: mouth, pharynx, esophagus, stomach, small intestine, large intestine
accessory organs: teeth, tongue, salivary glands, liver, gallbladder, pancreas
job of the oral cavity/teeth/tongue
mechanical processing, moistening, mixing with salivary secretions
job of the salivary glands
secretion of lubricating fluid containing enzymes that break down carbohydrates
job of liver
secretion of bile (important for lipid digestion), storage of nutrients, many other vital functions
job of pharynx
muscular propulsion of materials into the esophagus
job of gallbladder
storage and concentration of bile
job of pancreas
exocrine cells secrete buffers and digestive enzymes; endocrine cells secrete hormones
job of large intestine
dehydration and compaction of indigestible materials in preparation for elimination
job of esophagus
transport of materials to the stomach
job of stomach
chemical breakdown of materials via acid and enzymes; mechanical processing through muscular contractions
job of small intestine
enzymatic digestion and absorption of water, organic substrates, and ions
what is a mesentery?
extensions of the parietal peritoneum suspend the organs in the peritoneal cavity
what does it mean to be retroperitoneal?
lies posterior to the peritoneum
SADPUCKER
suprarenal glands aorta duodenum pancreas ureters colon kidneys rectum
falciform ligament
attaches liver to the anterior abdominal wall and abdomen
greater omentum
drapes over transverse colon and small intestine, attaches to greater curvature of the stomach and duodenum and transverse colon
lesser omentum
connects stomach and the duodenum to the lvier
mesentery proper
binds the jejunum and ileum to the posterior abdominal wall.
transverse mesocolon
transverse colon to posterior wall
sigmoid mesocolon
sigmoid colon to posterior wall
what are the layers of the GI tract? (deep to superficial)
1) lumen
2) mucosa
3) submucosa
4) muscularis
5) serosa
mucosa is made of ____ epithelium (2 types)
simple columnar (stomach and intestines) stratified squamous (mouth, pharynx, esophagus, anal canal)
submucosa contains the _____ plexus
sdubmucosal/plexus of Meissner-part of the enteric NS
muscularis contains the _____ plexus
myenteric/plexus of Auerbach-part of the enteric NS
what are the layers of the muscularis layer?
circular and longitudinal, modifications to the circular layer result in valves and sphincters
serosa is made of ____ CT
areolar
what is a villi and what is its purpose?
a folding in the mucosa to increase surface area
what is a plica?
a folding of the mucosa and submucosa
microbes ferment _____ _______ such as ______
undigestible compounds, starches, cellulose, pectins, sugars
what is the job of the bowel?
to digest food, absorb it into the blood and to keep the solution moving down the bowel at the right rate for digestion and absorption
what are the different phases of peristalsis?
1) contraction of circular muscles behind the bolus
2) contraction of longitudinal muscles ahead of bolus
3) contraction in circular muscle layer forces bolus forward
molars do what?
grind food
premolars do what?
crush and grind food
canines do what?
tear food
incisors do what?
cut food
purpose of the uvula
prevents swallowed food from entering the nasal cavity
fauces
opening between the oral cavity and oropharynx
parotid salivary gland
largest and thick secretion including amylase
what are the 3 salivary glands?
parotid, submandibular, sublingual
what are deciduous teethe?
primary/baby teeth
how many deciduous teeth are there? total and in categories!
20 total, 8 incisors, 4 canines, 8 molars
permanent/secondary dentition numbers
32 total teeth, all of the deciduous ones+3 additional molars on each side of upper and lower jaw
what are the layers of a tooth? (superficial to deep)
1) enamel
2) dentin
3) pulp cavity
4) root canal
enamel
calcium salts and protects the tooth from wear and tear
dentin
calcified connective tissue and makes up majority of the tooth
pulp cavity
contains pulp (CT containing nerves and blood vessels)
cementum
bone-like substance that attaches the root to the periodontal ligament
root canal
an extension of the pulp cavity that contains nerves and blood vessels
periodontal ligament
helps anchor the tooth to the underlying bone
apical foramen
an opening at the base of the root canal through which blood vessels, lymphatic vessels, and nerves enter a tooth
what are the three phases of swallowing?
buccal, pharyngeal, and esophageal
esophagus has no ____
serosa
what is special about the mucosa and submucosa of the esophagus?
have large folds to allow expansion
2 sphincters of the esophagus
1) upper esophageal
2) lower esophageal
the esophagus passes through the _____ in the _____ when moving to the abdomen
hiatus, diaphragm
regions of the stomach superior to inferior
cardia, fundus, body, pyloric antrum, pyloric canal, pylorus, pyloric sphincter
from where does the stomach receive blood from?
all three branches of the celiac trunk: 1) left gastric artery
2) splenic artery
3) common hepatic artery
what is a gastric pit?
invaginations of mucosa, opening into gastric glands
surface mucous cell secretes _____
mucus. no shocker there
mucous neck cell secretes ______
also mucus. surprise.
parietal cell secretes _____
HCl and intrinsic factor
intrinsic factor
involved in synthesizing B12, and formation of red blood cells
chief cells secrete_____
pesinogen and gastric lipase
G cells secrete _____
gastrin
what is the importance of the muscularis in the stomach?
churns the bolus to mix it with the enzymes, has oblique muscles that do this, makes chyme
oblique muscles of the stomach are only found in the
body
HCl
kills microbes in the food, denatures proteins, converts pepsinogen into pepsin
mucous is important for ____ and _____
protection, lubrication
gastrin
stimulates parietal cells to secrete HCl and chief cells to secrete pepsinogen; contracts lower esophageal sphincter, increases motility of the stomach and relaxes the pyloric sphincter
gastric lipase
splits triglycerides into fatty acids and monoglycerides
function of pyloric sphincter
opens to permit passage of chyme into the duodenum
which digestive organ has an endocrine and digestive function?
pancreas
exocrine pancreas releases___through a duct to the _____
digestive juices, duodenum
endocrine pancreas releases ____ into the _____
hormones, blood
pancreatic juice
clear, consisting of water, salts, sodium bicarbonate, and enzymes, alkaline
acinar cells of the pancreas secrete ____
digestive enzymes
duct cells of the pancreas secrete____
water and bicarbonate
accessory duct=____
duct of Santorini
Hepatopancreatic ampulla=______
ampulla of Vater
pancreatic duct=______
duct of Wirsung
pancreatic duct is a passageway for ____ into the ______
the acinar and duct cells byproducts, duodenum
common bile duct converges with the ____ to form the _____
pancreatic duct/duct of Wirsung, hepatopancreatic ampulla/ampulla of Vater
sphincter of the hepatopancreatic ampulla=_____
sphincter of Oddi
the pancreas receives blood from…
splenic artery. common hepatic artery, superior mesenteric artery
the liver produces_____
bile salts
the liver eliminates ____
bilirubin
the liver metabolizes_____ and _______
steroid hormones, drugs
the liver filters____ and removes____
blood, bacteria and particulate matter
the liver makes _____ and secretes it into the _____ _____ via the _____ _____ ______
bile, small intestine, common bile duct
excess bile is stored in the _______
gallbladder **bile also enters the small intestine through the common bile duct from the gallbladder when needed
lobes of the liver
left, right, caudate, quadrate
ligamentum teres
same as round ligament, free borders of the falciform ligament, remnant of umbilical vein of fetus
coronary ligament
extensions of parietal peritoneum that connect liver to the diaphragm
bile flow from the lover into duodenum
hepatocytes-bile canaliculi-small bile ducts-right and left hepatic ducts-common hepatic duct-common bile duct (or cystic duct for storage in gallbladder)-hepatopancreatic ampulla (ampulla of Vater)
hepatocytes arranged in _____
laminae
hepatic portal triad is made of ____, _____, and _____
bile duct, branch of hepatic artery, branch of hepatic portal vein
Kupffer cells are____ that _____
macrophages, phagocytize old blood cells, bacteria and foreign material
hepatocytes release…
ALT, AST, GGT, Bilirubin
hepatic blood flow
1) oxygenated blood from hepatic artery and nutrient-rich deoxygenated blood from hepatic portal vein converge in the hepatic sinusoids
2) central vein
3) hepatic vein
4) inferior vena cava
5) right atrium
hepatic portal vein contains _____ blood but also _____
deoxygenated blood, nutrients, drugs and possibly microbes and toxins from GI tract
gall bladder ____ bile and ____ to _____ bile into the _________
concentrates, secrete, cystic duct
bile from gallbladder to duodenum
cystic duct-common bile dutc-hepatopancreatic ampulla-duodenum
CCK is released by the _____ in response to _____ and _____ in chyme
small intestine, fatty acids, amino acids
CCK causes
the contraction of the gallbladder
small intestine divisions in order
duodenum, jejunum, ileum
what are circular folds of the intestines?
also calles plicae circulares, folds of the mucosa and submucosa, found in the duodenum and end about midway through the ileum
villi are ____ _____ of the _____
fingerlike projections, mucosa
microvilli are _____ formed by the folding of ______. form the ____
microscopic projections, each epithelial cell’s apical membrane, brush border
brush border enzymes
enzymes found on the plasma membrane of the microvilli
purpose of microvilli
absorptive cell (absorbs nutrients)
purpose of goblet cell
secretes mucus
enteroendocrine cell
secretes the hormones secretin, cholecytsokinin or GIP
small intestine: duodenum special features
plica, duodenal submucosal glands
small intestine: ileum special features
villi, aggregate lymphoid nodules (Peyer’s patches)
small intestine: jejunum special features
plica
large intestine has the _____ flexure and the _____ flexure
right colic/hepatic, left colic/splenic
haustra are…
those bubble things in the colon
teniae coli are…
smooth muscle that cause the haustra to segement feces
ileocecal sphincter/valve
sphincter between the cecum and ileum
the appendix is between the ___ and the ____
cecum, ileum
anus is guarded by the _____ and the _____
internal anal sphincter, external anal sphincter
___ of the rectal wall stimulates ____ _____ that activate the ______ _____
distention, stretch receptors, defecation reflex
external anal sphincter
skeletal muscle (voluntary),
internal anal sphincter
smooth muscle (involuntary)
intestinal glands=
crypts of Lieberkuhn
large intestine does not have ____ or ____ but the absorptive cells do have _____
plicae, villi, microvilli
haustral churning
moves contents from haustrum to haustrum by muscular contractions
mass peristalsis
forces contents into sigmoid colon and rectum
defecation reflex
eliminates feces by contraction in the sigmoid colon and rectum
