Chapter 32 Digestive System Part 2

rectum

between the sigmoid colon and the anus, forming anal canal

anal verge

boundary between the external and internal environment at the anus

pectinate/denate line

boundary between the internal mucosa and the external epithelium

Anus

The sphincteric muscle is located at the end of the anal canal, function in the retention of feces

Arterial supply to the anus and rectum includes

superior, middle, and inferior rectal artery

inferior phrenic arteries supply

diaphragm

celiac trunk supplies

foregut

superior mesenteric artery supplies

midgut

suprarenal arteries supplies

suprarenal glands

renal arteries supply

kidneys

gonadal arteries supply

gonads

inferior mesenteric arteries supplies

hindgut

common iliac arteries supply

peliv and lower limbs

celiac trunk

arises from the aorta below the aortic opening of the diaphragm

left gastric artery

• small branch that courses toward the left, then along the lesser curvature of the stomach

• gives off several esophageal branches

splenic artery

large branch of trunk that courses along upper margin of the pancreas then to the spleen

where the splenic artery gives off branches

• body and tail of the pancreas

• short gastric arteries to the fundus of the stomach

• left gastroepiploic artery to the greater curvature of the stomach

• the sleen before it ends

common hepatic artery

courses toward the right and divides into the hepatic proper and the gastroduodenal artery

Hepatic artery

• ascends in the lesser omentum towards the liver

• gives off the right gastric artery to the lesser curvature

• then divides into the right and left hepatic artery

right hepatic

gives off the cystic artery to the gall bladder

gastroduodenal artery

descends behind the duodenum and gives off 2 terminal vessels

right gastroepiploic artery

courses to the greater curvature

common stem of the 2 pancreaticoduodenal arteries

course to and supply the head of the pancreas and the duodenum

superior mesenteric artery

• arises from the aorta just below the celiac trunk

• lies posterior to the pancreas

• descends in front of the lower part of the duodenum- enters the mesentery- supplies the small intestine

most proximal branch

small pancreaticduodenal artery

what branches does the superior mesenteric artery give off

• small intestine: jejunal and ileal branches

• large intestine: ileocolic, right colic and middle colic arteries

ileocolic artery gives off branches to

the terminal ileum

inferior mesenteric artery

• arises from the aorta a few cm above its bifurcation

• courses toward the distal portion of the large intestine

• branches into the left colic, sigmoid, and superior rectal arteries

marginal artery of drummond

• formed by extensive anastomosis of ascending and descending branches of various arteries that supply the large intestine

• lies proxminty to inner margin of the colon

portal vein

contains nutrient-rich blood from the digestive system organs

2 tributaries that form the portal vein

1. splenic vein

2. superior mesenteric vein

inferior mesenteric vein drains into

the splenic vein

portal vein drains directly into

the liver

channel of lymph

organs then along the vessels towards the celiac nodes

liver

• largest gland in the body

• exocrine gland that produces bile

• bile is conveyed via ducts to the duodenum

2 surfaces of the liver

1. diaphragmatic (superior)

2. visceral (inferior)

diaphragmatic surface

related to the right dome of the diaphragm

viseral surface

• adjacent to the abdominal visera

• presents 4 lobes

lobes of the viseral surface of the liver

1. right

2. left

3. quadrate

4. caudate

Porta hepatis

junction of the 4 lobes

Structures that enter or exit the liver at the porta hepatis include

• right and left hepatic arteries

• right and left hepatic ducts

• portal vein

gall bladder

• located on the visceral surface of the liver between the right and quadrate lobes

• bile stored and concentrated here

• supplied by cystic artery

bile stored in gall bladder is drained by

the cystic duct

pancreas

both endocrine and exocrine glands

• endocrine: makes digestive enzymes that pass via duct to the duodenum

• exocrine: males the hormone insulin

head of pancreas

located in the con-cavity of the duodenum

body of pancreas

courses from the head toward the left across the vertebrae

tail of pancreas

left end of the gland, approximates the spleen

main portion of the pancreas drain juices via

main pancreatic duct into the major duodenal papilla

small upper part of the pancreas drain jucies via

accessory duct into the minor duodenal papilla

splenic artery supplies

body and tail of the pancreas

cystic duct joins the common hepatic duct to make

the bile duct

spleen

• acts as a large lymph node with additional functions

• located in the left upper quadrant of the abdomen

• lies left of the pancreatic tail and under the diaphragm