GI tract Flashcards
what is the primary function of the GI system
bring nutrients into the internal environment so that they can be used
Motility - movement of things through at appropriate rate
Secretion -
Digestion - breaking things down into smaller parts
Absorption -
what is the GI tract closed off at both ends with
sphincters - they are a circular region of muscle that can contract and relax; controlling the movement from one area to another
what is the GI tract lined with
epithelium - as technically the outside world
what are the major organs in order
oral cavity (mouth), pharynx, oesophagus, stomach, small intestine, large intestine, anus
What are the accessory organs
liver, pancreas, gall bladder, salivary glands, tongue and teeth
what kind of epithelia is found in the mouth and esophagus and why
stratified squamous - layers for protection
what kind of epithelia line the stomach and the intestines and why
simple columnar - for secretion and absorption as can fit cells in more easily
what cells line the anus and why
stratified squamous for protection
What is the peritoneum
serous membrane to protect the organs that move
What does the mesentary of the peritoneum do
Body wall to organ
What does the omenta of the peritoneum do
Link organ to organ
how is mucuc released in the oesophagus
Has glands with ducts to the surface to release them
What is the sphincter between the oesophagus and stomach
lower oesophageal sphincter
What is the order of the stomach parts from the oesophagus to the SI
Cardia, fundus, body, pylorus
Which part of the stomach does storage
Fundus and body
Which part of the stomach does Mechanical digestion
Antrum - which is the pylorus where there’s the most amount of muscle
What controls delivery of ffod from the stomach to SI
The pyloric sphincter
What are the muscularis layers of the stomach from inside to outside
oblique, circular, longitudinal
What are the folds of the stomach called and what is their purpose
Rugae - important for expansion of the stomach
What omenta connects the stomach to transverse colon
Greater omentum
what omenta connects stomach to liver
lesser omentum
What are the three regions of the SI in order
Duodenum, jejunum, ilium “don’t jump in”
Is the small intestine in the peritoneum
the duodenum is retroperitoneal but rest is intraperitoneal
What increases the surface area of the small intestine
Length
Plicae circularies - large folds, sub mucosa and mucosa
Villi - mucosa
Microvilli - just epithelial cells
What slows food in Small intestine
Plicae circularis
What connects the SI to the LI
the ileocecal valve
What are the regions of the large intestine
The cucum, Colon; Ascending, transverse, descending, sigmoid. Rectum
Which part of the lARGE Intestine is retroperitoneal
the ascending and descending colon
What muscles are found on the outside of the Large intestine
Teniae coli - longitudinal muscles
What are a series of pouches on a Large intestine called
Haustra
What does the LI absorb
water and salts
What is the name of the duct connecting the bile and pancreatic duct
The hepatopancreatic ampulla
Where does the blood from the SI travel
nutrient rich deoxygenated blood travels through mesenteric veins > hepatic portal veins > liver > heart
What cells in the liver produce Bile
Hepatocytes
What do G cells produce
Gastrin/ hormones in general
What do Chief cells produce
pepsinogen - the inactive form of pepsin
What do parietal cells produce
HCl
What do goblet cells produce
Mucus
Where are enzymes secreted from in the mouth and pancreas
Acinar cells
What cells produce Bicarbonate in mouth and pancreas
Duct cells
What are the monosaccharides
Glucose, fructose and Galactose
What are the disaccharides
Maltose, Lactose and sucrose
What is a transcellular pathway
through the cells
What is a paracellular pathway
between the cells
What is the mucosa of the gut made up of
Epithelium ^basement membrane between, lamina propria ^contains BV and lymph, muscularis mucosa
What is the submucosa of the gut made up of
Glands, BV, connective tissues
What is the muscularis made up of
smooth muscle - inner circular, outer longitudinal
what is Adventitia made of
FCT
