Alimentary tour Flashcards
6 salivary glands (2x)
parotid
sublingual
submandibular
four distinctive layer in oesophagus?
mucosa
submucosa
muscularis externa
serosa/adventitia
what is the nervous system in the gut called?
enteric nervous system
what controls motility in the gut? located?
myenteric plexus
located between circular and longitudinal muscle
what epithelium in mouth, oesophagus and anal canal?
stratified squamous
what epithelium in stomach, small & large intestine?
simple columnar
how many layers in muscular external and what do they do?
2 layers
inner layer = circular muscle which constricts lumen
outer layer = longitudinal muscle which shortens tube
parasympathetic control?
action?
vagus never everything below head and neck
stimulatory, increasing secretion and motility
sympathetic?
action?
splanchnic nerve?
decreases secretion and motility
What does celiac trunk supply? (4)
stomach/small intestine/ pancreas/ liver
what does the superior mesenteric artery supply? (5)
small intestine
caecum
ascending colon
transverse colon
what does the inferior mesenteric artery supply? (3)
descending colon
sigmoid colon
rectum
what controls the status of iron?
what transfers iron over brush border membrane?
ferritin
DMT1
control of salivary production?
Parasympathetic and sympathetic are both stimulatory
Parasympathetic by cranial nerves (facial & glossopharyngeal) resulting in profuse watery secretions
Sympathetic results in a small volume of viscous salivary secretion with high mucus content
reflex control by presence of food in the mouth
where is the swallowing centre?
medulla
what is vagus nerves’ effect on the stomach?
relaxation
Function of the stomachs:
fundus
body
antrum
fundus is for storage
body stores alongs mucus, HCI, pepsinogen and intrinsic factor
antrum is for mixing/grinding with G cells releasing gastrin
what does gastrin do?
stimulates HCI
increases contraction
peristaltic wave contraction in stomach?
body to Antrum
body has think muscle therefor weak with no contracting, antrum has thick muscle and therefor powerful contracting
what is chime?
a small amount of gastric content that enters the duodenum
peristaltic rhythm
(~3/min) generated by pacemakers cells in slow waves
what inhibits motility in duodenum? (4)
fat/AA/acid/hypertonicity
what neutralises acid in duodenum?
bicarbonate secretion from Brunners gland duct cells
Parts of pancreas? (4)
endocrine portion/exocrine portion/accessory pancreatic duct and sphincter of odd
Exocrine pancreas
responsible for digestive function of pancreas
functions to secrete bicarbonate by duct cells and secretion of digestive enzymes by acinar cells
digestive enzyme storage?
acinar cells contain digestive enzymes stores as inactive zymogen granules (prevents auto digestion)
how does zymogens get active?
enterokinase (brush border) converts trypsinogen to trypsin which converts all zymogens to active form
Liver has 2 major and 2 minor lobes?
right and left
caudate and quadrate
entry and exit of blood vessels happens where?
Porta on inferior surface
portal triad?
hepatic portal vein
hepatic portal artery
hepatic duct
function of liver in an alimentary role?
production and secretion of bile
six components of bile?
bile acid bile pigments bicarbonate cholesterol lecithin toxic metals
Bile pigments?
breakdown products of haemoglobin
Sphincter of Oddi?
controls the release of bile and pancreatic juices, when contracted bile is forced back into the gallbladder where it is is CONCENTRATED and when fat is present in duodenum releases CCK which relaxes sphincter of Oddi and gallbladder contracts
Defecation reflex?
parasympathetic control via pelvic splanchnic nerves
