Gi Tract Part 2 Flashcards
Which 3 branches leave the aorta and supply gi tract and what lumbar level
Coeliac trunk (superior of L1)
Superior mesenteric artery (inferior of L1)
Inferior mesenteric artery (L3)
What does coeliac trunk supply
Oesophagus, stomach, liver, superior duodenum and pancreas
What are the main branches of coeliac trunk
Left gastric artery (which has oesophageal branches)
Common hepatic
Splenic artery
What supplies the stomach
The left and right gastric supply the lesser curvature
Left and right gastroepiploic supply greater curvature
What are the branches of the splenic artery
Short gastric branches for fundus supply
Splenic branches
Left gastroepiploic
What supplies the superior duodenum and pancreas and what does it stem from
The pancreaticoduodenal artery
The right one is a branch from the common hepatic artery
What else supplies the pancreas
The splenic artery
Where does the right gastric artery stem from
Also the common hepatic duct and supplies also the lesser curvature of stomach
Which other 3 branches of the common hepatic are there
Left branch, right branch and the cystic artery
What does the superior mesenteric supply
From inferior duodenum to the right colic flexure
Supplies all of the si from inferior duodenum
Suppplies large from vermiform appendix/caecum to right colic flexure and transverse colon
Also supplies the inferior pancreas/duodenum
What from the superior mesenteric supplies pancreas and inferior duodenum
Inferior pancreaticoduodenal artery
What are arcades
Large loops of branches which supply the jejunum and ileum
Where are the arcades
In the mesentery (peritoneum which attaches si to wall)
Which branch from superior mesenteric supplies the terminal ileum, vermiform appendix and inferior ascending colon
Ileocolic artery
Which artery supplies the superior ascending colon and the transverse colon
Right colic artery and middle colic artery for transverse
Which branch artery from the inferior mesenteric branch anastomoses with the middle colic artery from the superior mesenteric
The left colic artery
Which artery branch from inferior ma supplies the sigmoid colon
Sigmoidal
Which part of the rectum is supplied by the superior rectal artery branch of ima
The proximal rectum (distal not supplied by abdominal aorta)
What are the parts of the stomach
Fundus Body Antrum Pyloric sphincter Lesser curvature at top Greater curvature below
What do the fundus and body secrete and from whcih cells
Gastric acid from parietal cells
Pepsinogen from chief cells
What does the antrum release
Endocrine like histamine, gastrin and somatostatin
What do these endocrine do
Control secretions and gastric motility
What are the incisions which look like villi but aren’t called in stomach mucosa
Gastric pits
Where are the parietal usually
Top of the gastric pits/ mucosa and they’re surface epithelial
What is diff about the muscularis externa of the stomach
Has inner oblique muscles inner to even circular muscles
What are they for
Distension of stomach/ bloating
Which type of epithelium are in stomach
Columnar
Which 2 things in stomach help protect from pathogens and acid
Tight junction between epi cells
Alkaline secretions by mucous cells neutralise acid
Are there goblet cells in stomach
No just mucous cells
What is the peritoneum
Layer of connective tissue covering the abdominal organs
What peritoneum covers the stomach
Omentum
What covers the intestines
The mesentery
What is the space within the peritoneum between organs
Peritoneal cavity
What is the job of peritoneum
Anchors organs to posterior body wall and allows blood supply to them via vessels
What is the part where peritoneum is disrupted in the higher abdomen
The falciform ligament
What are the 4 parts of duodenum starting superior
Superior
Then descending to L3
Then horizontal
Then ascending to L2 (where it becomes jejunum)
Which part of small intestine receives digestive secretions
Descending
From where
The bile duct transporting secretions from liver and gb
And from pancreas via pancreatic duct
Where is superior
Superior and Posterior to L1
Where is descending and what does it cross over
At level of L3 and crosses over kidney
Where is and where does horizontal duodenum travel
At L3 and travels to left across the aorta
Where is the ascending and where does it become the jejunum
It is to the left of the aorta and at L2 becomes jejunum
Where are the primary sites of absorption
Jejunum and ileum
Which is longer
Ileum 3/5 metres
What is the mesentery an extension of
The serosa
What is the functional unit of absorption in intestines
The villi in the small intestine
What sort of epithelium are on the villi and crypts
Simple columnar
Which vessels does each villi contain and what do they transport
Capillary and a lymph vessel
Capillary transports absorbed aa and monosaccharides
Lymph vessel carries fats absorbed in the intestine
Where do they carry these absorbed materials to
Portal vein
What are the 4 types of cells in small intestine
Absorptive/enterocytes
Goblet
Granular
Apud cells
Which ascend up the villi and which stay in crypt
Granular and apud stay in crypt
Absorptive and goblet ascend up and then renewed
Which are most important for absorption and secrete digestive enzymes
Absorptive / enterocytes
What are granular cells for
Secrete enzymes and protect epithelium from bacteria
What are apud cells for in the crypt
Endocrine secretions which control motility and secretions of gi
Where is the liver
Right upper quadrant to the epigastric region
Under the diaphrsgm
Explain the structure of the liver
Large right lobe and left smaller lobe
Divided by the falciform ligament
Below and on the posterior view is the gall bladder linking to the common bile duct
Which vessels seen on liver
Hepatic artery and portal vein (from intestines)
Also inferior vena cava linked to hepatic veins
What does portal vein contain which needs filtered in liver and explain path from capillaries to liver
Monosach, aa , fats from the capillaries and lymph vessels of si
Capillaries go into mesenteric veins then into the portal vein then enter (deox blood)
Other than intestines what does portal vein receive blood from
Spleen and stomach
What epi cells in liver form a 3d lattice shaped like a hexagon
Hepatocytes
What runs between hepatocytes and allows them to be in contact with the portal blood
Sinusoids
What 3 vessels are in liver lobules (hexagon shape)
Portal vein, bile duct and hepatic artery (supplies ox blood)
How do products of hepatocytes drain to left/right bile duct
Canaliculi channels
Where does bile drain from liver
The right and left hepatic bile ducts which join to form the common hepatic duct which then joins the cystic duct from bile to for common bile duct
Where does bile from common hepatic duct go
Either gall bladder for storage or straight to descending duodenum
What triggers bile to drain from gb down cystic down cbd to duodenum
Food in the duodenum
What do all ducts combine to form
Biliary duct
How does liver have glucose functions
Stores it as glycogen in glycogenesis in insulin presence then releases it via glycogenolysis
Which 3 things other than bile does liver synthesise
Cholesterol, lipoproteins and proteins
Which protein is a transporter and most abundantly made in liver
Albumin
What does it do
Transporter but also helps maintain fluid reabsorption in tissues from blood
What would happen without albumin
Oedema
Which other proteins are made in liver
Clotting factors
What are cholesterols used for
Cell membranes or sex hormones or excreted if waste in bile
What are bile salts for
Emulsifying lipids so they increase sa for better absorption
Which vitamins does liver fat store
Aedk
What happens to drugs and their metabolite byproducts in liver
Either excreted in bile or released to blood to excrete form kidney
What does ammonia get converted to in liver for kidney release
Urea
What from spleen is modified by liver to be excreted in bile
Bilirubin from old rbc
Where is bile made
Hepatocytes
What in bile increases ph and why
HCO to reduce gastric acidity and prevent intestinal damage
Where is the pancreas
Superior umbilical region crossing to left lumbar. Deep and inferior to stomach. Horizontal across posterior body wall
What is the exocrine gland called of pancreas which releases enzymes for digestion from the acinus
Tubuloacinar gland
Where does the pancreatic juice from acinus get modified
In the ducts
What does pancreatic juice in pancreatic duct join to form the ampulla of vater
The common bile duct
What controls the engerance of juices from pancreas to descending duodenum
The sphincter of oddi
Which 2 elements does pancreatic juice have
Alkaline HCO to neutralise the gastric acid
Pre enzyme secretions whcih get activated in the gut for digestion
What innervates pancreatic juice secretions
Ans where sns refuces vs PNS increases
Also other endocrine influence it
What are the prepeptidases (pre enzymes) released from pancreas called
Zymogens
Which zymogen is converted to active first
Trypsinogen to trypsin
What does the trypsin then allow
Activation of procarboxypeptidase to carboxypeptidase and also chymotrypsinogen to trypsinogen
What sort of epi cells are in colon LI
Simple columnar
Give the differences in the cells from si
Not villous, only have crypts
Also have absorptive, goblet and apud but apud are more sparse
Have more goblet cells than si
Where does the caecum first section of li start
The ileocaecal junction (right inferior quadrant)
What does caecum contain
The vermiform appendix
How is the longitudinal muscle in the colon (except for appendix anal and rectum) different
Is incomplete and forms 3 bands called taenia coli
What are they for
Peristalsis aiding
Where does rectum begin
S3
What are the wiggly lines where rectum meets anis
Zone of epithelium called the anal columnw
What is below the anal column
Anal canal and the internal/external anal sphincters
What is the pubic muscle called around the Anus and rectum
Puborectalis
What is the main function of the large intestine
Absorb water and ions through absorptive cells
Where in the colon are some nutrients also absorbed
Proximal colon
What is the mnemonic to learn the abdmonial aorta branches
In (inferior phrenic nerve to diaphragm) Case (coeliac) My (middle suprarenal) Students (superior mesenteric) Really (renal) Love (lumbar multiples) Games (gonadal) I’m (inferior mesenteric) Monopoly
What are the branches from splenic
Short gastric for fundus
Splenic branches to spleen
Left gastroepiploic for greater curvature
What are the common hepatic branches
Right and left hepatic
Cystic artery
Gastroduodenal
Right gastric to right lesser curvature
What does gastroduodenal branch to
Anterior and posterior pancreatico duodenal branch
And right gastroepiploic for right greater curvature
Which branch from superior mesenteric anastomses with a branch from coeliac
The inferior pancreaticodudenum which supplies inferior duodenum and pancreas. Anastomses with the hepatic branch of superior pancreaticoduodenum from gastro duodenal branch
Explain the levels of duodenum
Superior is at L1 from the stomach
Descending travels across kidney at L3
Horizontal travels across aorta at L3
Ascending goes to L2 on left of heart where it starts jejunum
What are sinusoids
Channels running from the hepatic vein to the triad/portal vein+hepatic artery+ bile duct
