Anatomy of the GIT Flashcards
name the 9 regions of the abdomen
R/L hypochondium, RL flank, RL inguinal, epigastric, umbilical and pubis
what is the mesentery made up of
joining of the right and left parietal peritoneum on the posterior side of the abdomen wall
what is the function of the mesentery
allow innervation of nerves and blood supply to the organs
what is the layer called that covers viscera
visceral peritoneum
what structures are retroperitoneal
ascending and descending colon
rectum
duodenum
what structures are intraperitoneal
stomach ileum caeceum jejunum transverse and sigmoid colon
describe the structure and role of the stomach
highly distensible heavily folded sac for mechanical and chemical breakdown of food producing chyme
what allows the stomach to be suspended in the peritoneum
greater and lesser omentum
what is the structure and function of the greater omentum
extends down the inferior border of the stomach and sits as an apron. responsible for fat deposition for protection, immune contribution and wound isolation
what is the structure of the lesser omentum
runs from the lesser curvature of the stomach to the liver and has a free edge on the right lateral surface
what runs in the free edge of the lesser omentum
portal vein
hepatic artery
hepatic bile ducts
hepatic plexus of nerves
what tube enters the stomach - what is at the exit of the stomach
oesophagus and the duodenum
what is the highest point of the stomach called?
fundus
what is the largest part of the stomach called
body
what is the first part of the stomach called from the oesophagus
cardia
what is the region called before the exit of the stomach and which part is closest to the duodenum
pyloric canal is closest to the duodenum and pyloric anthem is closest to the body
what three regions make up the small intestine
duodenum
jejunem
ileum
what is the function of the duodenum
primary site of nutrient absorption
what is the role of the mesentery in the small intestine
connect the jejuneum and ileum to the posterior abdomen wall
what sides of the body do the jejunum and the duodenum start within the sections of the abdomen
duodenum is right upper side (RH)
jejunum is middle left (LF)
describe the anatomy of the large intestine from right to left including flexures
caecum (appendix) - ascending colon - right colic flexure - transverse colon - splenic flexure (left colic) - descending colon - sigmoid colon - rectum - anal canal
what is the main function of the large intestine
water absorption and transmit of waste to the rectum
where does the pancreas sit
posterior to the stomach on the posterior abdomen wall, sits in the concave c aspect of the duodenum
what is the exocrine function of the pancreas
secrete pancreatic juice via ducts to the duodenum
what is the endocrine function of the pancreas
secrete insulin and glucagon into the blood
describe the route and joining ducts of pancreatic juice to the duodenum
main pancreatic duct joins with the bile duct from the liver forming the hepatic-pancreatic ampulla (sphincter of oddi), the ampulla opens up into the duodenum via the major duodenal papillae
where does the spleen sit
left lateral abdominal wall against the 9th 10th and 11th rib
what is the function of the spleen and why is it easy to damage
lymphatic organ and helps to filter out dead or damaged rbc
it is a superficial organ and can be penetrated by broken ribs
what separates the anterior and posterior part of the tongue
v shaped ridge - terminal sulcus
what are the four taste buds from anterior to posterior to posterior-lateral
fungiform (papillae)
filliform
vallate
foliate
what is the role of the tonsils
immune glands that fight infection
what are the five flavours on the tongue
umami bitter sweet satly sour
what three structures make up the pharynx
nasal cavity
oral cavity
larynx
what is the function of the epiglottis
seal of the windpipe when swallowing - also aids in phonation
what is peristalsis
descending contractions of circular smooth muscle
what division of the nervous system controls peristalsis
enteric nervous system
how long is the oesophagus
25cm
where does the oesophagus lie
posterior to the trachea
posterior to the aortic arch
posterior to the heart
how does the oesophagus enter the thorax
via the thoracic inlet
where does the blood supply to the go tract come from
abdominal aorta
what organs are supplied by the coeliac trunk
foregut: osephagus stomach proximal half of duodenum liver and gall bladder pancreas spleen
what organs are supplied by the superior mesenteric artery
distal half of duodenum jejunum ileum caecum ascending column proximal 2/3 of the transverse
what organs are supplied by the inferior mesenteric artery
distal 1/3 of the transverse
descending column
sigmoid column
rectum
at which vertebral level do the colic trunk, superior and inferior mesenteric artery leave the aorta
T12
L1
L3
what percentage and what source does the lover receive its blood supply
hepatic artery 20%
nutrient rich and high in oxygen
what is the role of the portal system
deliver blood from the gut to the liver allowing detoxification of absorbed substances from the gut - venous blood is returned to systemic circulation via the hepatic veins
what does cirrhosis causes and how does it resolve this
hypertension in the portal vein
utilise a series of redundant portal systemic anastomoses which allow blood to return to the heart
where within the abdominal regions does the liver lie
the RH, epigastric and part of the LH
what is main function of the liver
detoxify ingested substrates, protein synthesis, storage of glycogen and production of bile
what can you see on the anterior view of the liver
right lobe
left lobe
falciform ligament
what is the falciform ligament made up of and what is its role
peritoneum
attaches liver to anterior wall
what can you see from the posterior view of the liver
right lobe left lobe caudate and quadrate gall bladder inferior vena cava
the free margin of the falciform ligament is thickened, what ran here before development and what has it become
umbilical vein which is now the round ligament of the liver
which is the biggest lobe of the liver
right lobe
how many functional segments are in the liver and why is this good
8
if you need to remove a tumour from surgery you still have 7 other functioning lobes
is the liver retroperitoneal
no the liver is mostly intraperitoneal except for a small region on its superior posterior border
what is the blood supply of the liver
hepatic artery branches
portal veins
where does the gall bladder lie
between the right and quadrate lobes
what is the function of the gall bladder
STORAGE and concentration of bile
what ducts does bile exit the liver and travel to the duodenum
hepatic ducts leave the liver
form the common hepatic duct
joining of the cystic duct from the gall bladder forms the bile duct.
bile duct forms with the pancreatic duct and enters the second part of the duodenum
what part of the ANS must be active to allow bile into the duodenum - what happens during the opposite
parasympathetic must be stimulated
during sympathetic is causes contraction of the hepatopancreatic sphincter - bile therefore is pushed upwards into the gal bladder via the cystic duct
what three layers make up the stomach
mucosa (inner), submucosa and muscularis externa
what are the 6 cells of the stomach
D/G cells (enteroendocrine cells) surface mucus cells parietal (oxygenic) cells stem cells mucus neck cells chief cells
what are the differences in histology of the small intestine to the large intestine
small intestine has 4 layers
small intestine has microvilli in proximal 2/3
contains plicae ciricularea
small intestine has mucosa and submucosa
large intestine has more goblet cells to secrete mucus for faeces
why does the pain moves in appendicitis
goes from central to right lilac fossa due to referred pain
function of parietal cells
chief cells
g cells
d cells
secrete HCL
secrete pepsinogen and lipase
secrete gastrin - stimulate HCL and pepsinogen release
secrete somatostatin which inhibits gastrin
what causes peptic ulcer
high alcohol or aspirin abuse causing high acidity in the stomach
what are teanae coli
haustra
epiploic appendages
three brands of smooth muscles
bulges caused by contraction of smooth muscle
fat accumulations
what is diverticulosis what causes it and what can in lead to
outpockets of the mucosa that push through the outer muscular layers
caused by poor fibre in the diet
can lead to diverticulitis which is when one or more become inflamed and infected