53. GI anatomy part 3

Question 1

What is the most common position of the appendix?

Answer 1

Pelvic (5 o’clock)- google

retrocecal (11 o’clock)- teach me anatomy

Question 2

How is the appendix supplied?

How is the appendix lymphatically drained?

Answer 2

Appendicular artery

Ileoceacal nodes

Question 3

What is the function of the cecum?

Answer 3

Reservoir for chyme

Question 4

How is the cecum supplied?

Answer 4

The ileocolic artery

Question 5

What is the hepatic flexure?

Answer 5

Marks the end of the ascending and beginning of transverse colon.

Question 6

What is the splenic flexure?

Answer 6

Where the transverse colon stops and the descending colon begins. Attached to the diaphragm by the phrenicocolic ligament

Question 7

What distinctive features differentiate the large colon from the rest of the GI tract?

Answer 7

Omental appendices- small pouches of perinternum filled with fat

Teniae coli- three strips of muscle that shorten the wall of the bowel

Haustra- segmented structures formed when the haustra contract

Question 8

How is the ascending colon supplied by arteries?

Answer 8

Supplied by the superior mesenteric artery:

ileocolic and right colic arteries

Question 9

How is the transverse colon supplied arterially?

Answer 9

Right colic artery (superior mesenteric artery)
Middle colic artery (superior mesenteric artery)
Left colic artery (inferior mesenteric artery)

Question 10

How is the descending colon supplied?

Answer 10

Left colic artery (branch of superior mesenteric artery)

Question 11

Why is the marginal artery of drummond important?

Answer 11

Provides collateral supply to the colon incase of occlusion or stenosis.

Question 12

How is the rectum supplied/drained?

Answer 12

Superior rectal artery/vein
Middle rectal artery/vein
Inferior rectal artery/vein

Question 13

What structure of the anus relaxes to promote feacal loading?

Answer 13

The ampulla

Question 14

Discuss the histology of the anal canal?

Answer 14

Contains a pectinate line where the anus is divided in tow

Upper part is keratinised squamous epithelium

Lower part is non keratinised stratified squamous epithelium

Question 15

What is the function of the liver?

Answer 15

Glycogen storage
Detoxification
production of clotting factors
Bile synthesis

Question 16

What are the major ligaments of the liver (4)

Answer 16

Falciform Ligament- divides liver into left and right

Coronary ligament (anterior and posterior fold)- demarcates bare area of liver. Liver to diaphragm

Triangular ligament (left and right)- edges of liver to diaphragm

Lesser Omentum- combination of hepatoduodenal ligament and hepogastric ligament

Question 17

Where is peritoneal fluid most likely to collect in a supine patient

Answer 17

Morison’s pouch

potential space between the visceral surface of the liver and the right kidney

deepest part of peritoneal cavity

Question 18

Describe the four lobes of the liver?

Answer 18

Right and left lobe separated by the falciform ligament

Caudate lobe- lies on the superior aspecty of the visceral surface (underside) beside the IVC.

Caudate- Lies on inferior aspect of visceral surface,lies between the gallbladder and ligamentum teres

Question 19

What separates the caudate and quadate lobe?

Answer 19

known as the porta hepatis. It transmits all the vessels, nerves and ducts entering or leaving the liver with the exception of the hepatic veins

Question 20

Describe the arrangement of the liver microscopically

Answer 20

hexagonal arrangement of hepatocytes with a central vein in the middle. At the periphery of the hexagon are the portal triad (arteriole, venule and bile duct)

Sinusoids act as fenestrated capillaries to allow for filtration

Question 21

Explain the blood supply to the liver?

Answer 21

hepatic artery (25%)

Hepatic portal vein (75%)- contains nutrients and partially deoxygenated blood

Question 22

What are the indications for a liver biopsy

Answer 22

Abnormal LFT’s
Liver Malignancy
Hep C
Following liver trasnplant

Question 23

What are the two types of liver biopsy?

Answer 23

Subcostal approach

Transvenous biopsy (clotting disorder)