6: Abdominal Midgut And Hindgut

Question 1

Are jejunum and ileum retro or intraperitoneal?

Answer 1

Intraperitoneal

Question 2

How much of the SI is jejunum vs ileum

Answer 2

Jejunum: proximal 2/5ths
Ileum: distal 3/5ths

Question 3

Blood supply to jejunum and ileum

Answer 3

Jejunum: long vasa recta off SMA
Ileum: short vasa recta off SMA

Question 4

Colon length

Answer 4

1.5 meters

Question 5

What are the fatty appendages on haustra called?

Answer 5

Appendices epiploicae

Question 6

Where are ileal papilla?

Answer 6

Cecum

Question 7

Ileocecal valve

Answer 7

Regulates passage into cecum

Question 8

What does the appendix contain

Answer 8

Several lymphoid nodules

Question 9

Where is the appendix?

Answer 9

Attached to posteromedial cecum, supported by mesoappendix

Question 10

What two parts of the colon are secondarily retroperitoneal

Answer 10

Ascending and descending colon

Question 11

At what level does the sigmoid colon join rectum?

Answer 11

S3

Question 12

What suspends the transverse and sigmoid colons?

Answer 12

Transverse: transverse mesocolon mesentery
Sigmoid: sigmoid mesocolon

Question 13

Rectum is both retroperitoneal and what?

Answer 13

Sub-peritoneal

Question 14

Three transverse rectal folds

Answer 14

Superior, middle, and inferior folds in rectum

Question 15

Pectinate line location

Answer 15

At inferior ends of anal valves

Question 16

Of the many anastomoses between SMA and IMA, name one

Answer 16

Marginal artery (of Drummond)

Question 17

Three arteries to the rectum and what they branch from

Answer 17

1. Superior rectal: IMA
2. middle rectal: internal iliac A
3. Inferior rectal: internal pudendal

Question 18

Three plexuses where the portal venous system has anastomoses with the systemic system

Answer 18

Gastroesophageal plexus, umbilicus, rectal venous plexus

Question 19

What is notable at the plexuses where portal and systemic blood can mix?

Answer 19

Varices can occur here due to decreased blood flow through liver

Question 20

What artery’s branches do the sacral splanchnics run with on the way to the pelvic viscera

Answer 20

Internal iliac A

Question 21

Four parts of the preaortic plexus

Answer 21

Celiac ganglia, SMA ganglia, IMA ganglia, aorticorenal ganglia

Question 22

Somatic vs visceral afferent pathways

Answer 22

Somatic: pain from irritation of peritoneum
Visceral: pain from organ itself

Question 23

How does the somatic afferent pathway work?

Answer 23

Brain interprets pain as though irritation occurred in skin of region supplied by same sensory ganglia and SC segments

Question 24

How does the visceral afferent pathway work?

Answer 24

Pain is transmitted via splanchnic nerves to spinal cord, but is poorly localized so it radiates to same dermatome level receiving visceral afferents