Structure of abdomen

Question 1

four diaphragm primordia and what they form

Answer 1

septum transversum: most of central tendon. Mesentery of esophagus: muscular crura and middle central tendon. Pleuroperitoneal membranes: part of central tendon. Body wall: muscle

Question 2

structures perforating diaphragm and at what levels

Answer 2

T8: vena cava, T10: esophagus, T12: aortic hiatus (aorta, thoracic duct, azygos vein)

Question 3

three types of diaphragmatic hernia

Answer 3

congenital: failure of pleuropeitoneal membranes to fuse (posterolataral defect with abdominal organs in thorax). Sliding hiatal: is most common. GE
junction is displaced ^; “hourglass stomach.”. Paraesophageal hernia—GE junction is normal.
Fundus protrudes into the thorax.

Question 4

omphalocele vs gastroschisis

Answer 4

midgut fails to return from umbilical cord (covered by peritoneum). Failure of left and right somatopleure to fuse, abdominal contents extrude thru folds (not covered by peritoneum)

Question 5

nine regions of abdomen

Answer 5

Epigastric, umbilical, suprapubic flanked by L and R hypochondriac, lumbar, inguinal

Question 6

what primordial tissue do the organs develop from

Answer 6

splanchnopleure. Parenchyma (epithelium of GI tract) from endoderm and stroma (SM, CT, vasculature, visceral peritoneum) from lateral plate mesoderm

Question 7

3 branches of celiac trunk

Answer 7

splenic, L gastric, common hepatic (then divides into hepatic proper and gastroduodenal). All give blood supply to foregut.

Question 8

Branches of S Mesenteric

Answer 8

ileocolic, R colic, Middle colic, intestinal branches All give blood supply to midgut.

Question 9

branches of I mesenteric

Answer 9

L colic, sigmoid branches, S rectal. All give blood supply to hindgut

Question 10

define: arcade, vasa recta, marginal artery

Answer 10

looping anastomoses. Go straight to intestine from arcades. Follow contour of colon

Question 11

parasympathetic path to gut

Answer 11

foregut and midgut: vagus. Hindgut: pelvic splanchnic nerves (S2,3,4). Presynaptics synapse in Myenteric (auerbach’s) plexus for SM and submucosal (meissner’s) plexus for glandular secretion and muscularis mucosase

Question 12

path of sympathetics

Answer 12

thoracic (abdominal) and lumbar (pelvic) splanchnics synapse on collateral (prevertebral) ganglia and innervate arteries and adrenal glands

Question 13

spinal cord segments for visceral sensory of: heart, stomach, appendix, left colic flexure to sigmoid colon

Answer 13

T1, T7-T9, T10, L1-L5

Question 14

somatic pain, visceral pain, referred pain.

Answer 14

intense sensation carried by general sensory neurons in body wall. Mostly dull sensation carried by visceral sensory neurons in organs (except: stones, appendicitis, spasm, ulcers). Originates in one location and felt in another supplied by same spinal segment (peritonitis under diaphragm felt in C3,4,5 dermatomes of shoulder)

Question 15

four lobes of liver

Answer 15

left, right, caudate, quadrate

Question 16

portal triad

Answer 16

in the “cross bar” of the H on underside of liver. Consists of Bile duct, hepatic artery, portal vein

Question 17

portal-caval anastomoses and associated signs of portal HTN

Answer 17

Left gastric veins (esophageal varices), para umbilical veins (caput medussa), superior rectal veins (hemorrhoids)

Question 18

describe formation of pancreas

Answer 18

ventral bud swings around to form head and uncinate process with main duct. dorsal bud becomes body and tail and isthmus and accessory duct

Question 19

two abnormal pancreas formation conditions

Answer 19

annular pancreas, pancreas divisum