Anatomy

Question 1

a) the embryo undergoes which two folds to form the gut
b) at 4 weeks the cranial and caudal end are still enclosed by which two membranes

Answer 1

a) cranial-caudal, lateral
b) bucco-pharyngeal, cloacal

Question 2

what does the foregut, midgut and hindgut contain

Answer 2

a) foregut: oesophagus, stomach, liver, pancreas, proximal half duodenum
b) midgut: distal half duodenum, jejunum, ileum, cecum, ascending colon, 3/4 transverse colon
c) hindgut: 1/4 transverse colon, descending colon, sigmoid colon, rectum

Question 3

which mesentery doesn’t degenerate during development

Answer 3

ventral mesentery in foregut

Question 4

dorsal vs ventral mesentery

Answer 4

dorsal: attaches gut organs to posterior abdominal wall (back)

gives rise to: gastrosplenic ligament, lienorenal ligament, greater omentum, mesentery of small and large intestine

ventral: at foregut region only, gives rise to:

ligaments around liver, falciform ligament, lesser omentum

lesser omentum attaches lesser curvature of stomach to back of liver, and has a free edge

Question 5

what are the 4 muscles of anterior abdominal wall

what is function, blood supply and innervation for each

Answer 5

external oblique: work with internal oblique for torsional movement of trunk

internal oblique: flex and rotate trunk, compress viscera

transversus abdominis: compress and support viscera

rectus abdominis: flexes trunk; compresses viscera

blood supply: arteries: sup and inf epigastric, intercostal and circumflex iliac

veins: thoracoepigastric
innervation: thoracoabdominal nerves, thoracic and subcostal nerves for rectus abdominus

Question 6

how does the lesser and greater sac of peritoneal cavity communicate

Answer 6

epiploic foramen of winslow

Question 7

the inguinal canal serves as a passageway for what in:

a) males
b) females

and why are males more likely to develop a hernia in the inguinal canal?

Answer 7

a) spermatic cord to reach scrotum in males
b) round ligament of the uterus to reach labia majora in females

males inguinal canals are considerably larger, therefore more likely to develop a hernia

Question 8

the spermatic cord passes through abdominal wall taking a covering from 3 layers

what are the 3 layers it takes from and what do these become in around the spermatic cord

Answer 8

1. transversalis fascia contributes to internal spermatic fascia
2. internal oblique contributes to middle cremasteric fascia
3. external oblique contributes to external spermatic fascia

Question 9

which 3 layers comprise the whole alimentary system (oesophagus, stomach, colon etc), and their functions

Answer 9

1) serous layer: outer membrane encloses body cavities, secretes lubricating fluid from outer epithelial layer, inner layer is connective tissue with vessels
2) muscular layer: longitudinal or circular, responsible for movement of lumen contents
3) mucosal layer: inner layer, lines internal organs and cavities, exposed to external environment, secretes mucus, involved in absorption

Question 10

name the two orifices which link stomach to

a) oesophagus
b) small intestine

Answer 10

a) cardial orifice
b) pyloric orifice

Question 11

branches of superior mesenteric artery?

branches of inferior mesenteric artery?

include what body parts each supplies

Answer 11

superior mesenteric: supplies distal part duodenum to proximal 2/3 transverse colon

has jejunal, ileal, middle colic, right colic and ileocaecal branches

inferior mesenteric: supplies distal 1/3 transverse colon to half way down anal canal

has left colic, sigmoid and superior rectal branches