Neurovascular supply of abdomen

Question 1

What are the 3 unpaired arteries that supply the abdomen?

Answer 1

Celiac trunk (T12)

• gives off left gastric a, splenic a, and common hepatic a
• supplies foregut (oesophagus, stomach, duodenum, liver, gallbladder, pancreas, spleen)

Superior mesenteric artery (L1)
- supplies midgut (pancreas, duodenum, ileum and jujenum, cecum, appendix, ascending and transverse colon)

Inferior mesenteric artery (L3)
- supplies hindgut (descending colon, sigmoid, rectum)

Question 2

What are the 3 branches of the celiac artery, and what do they supply?

Answer 2

Left gastric:
- stomach and adjacent oeseophagus

Splenic
- stomach, spleen and pancreas

Common hepatic
- stomach, duodenum, liver, gallbladder, pancreas

Question 3

What are the 3 branches of the inferior mesenteric artery, and what do they supply?

Answer 3

Left colic
- descending colon

Sigmoid
- sigmoid colon

Superior rectal
- rectum

Question 4

What are the 6 branches of the superior mesenteric artery, and what do they supply?

Answer 4

Middle colic:
- transverse colon

Right colic:
- ascending colon

Ileocolic:
- terminal ileum and caecum

Appendicular:
- appendix

Intestinal aa
- small intestines

Anterior and posterior inferior pancreaticoduodenal aa:
- pancreas and duodenum

Question 5

What are the 5 paired arteries that supply the abdomen?

Answer 5

Inferior phrenic (T12)
- diaphragm, inferior oesophagus

Adrenal (L1)
- adrenal glands

Renal (L2)
- kidneys

Gonadal (L2)
- testes or ovaries

Lumbar (L4)
- vertebrae, spinal cord, abdominal wall, lumbar region

Question 6

What are the 5 major veins that drain blood from the abdomen?

Answer 6

Inferior Mesenteric Vein:
- drains blood from hindgut into splenic v

Splenic Vein:

• drains blood from foregut
• unites with SMV to form hepatic portal vein

Superior Mesenteric Vein:

• drains blood from midgut
• unites with splenic v to form hepatic portal vein

Hepatic Portal Vein:

• drains blood from foregut, midgut and hindgut to the liver via portal circulation
• blood enters lobules via hepatic portal vein in portal triad
• blood filters through lobules and enters central vein
• central veins drain into hepatic vein, which drains into inferior vena cava

Inferior Vena Cava:
- drains blood from hepatic veins into the right atrium

Question 7

Which veins unite to form the hepatic portal vein?

Answer 7

the superior mesenteric vein and the splenic vein (unite behind the head of the pancreas)

Question 8

Where does the inferior mesenteric vein drain into?

Answer 8

The splenic vein (which then unites with the superior mesenteric vein to form the hepatic portal vein)

Question 9

Which arteries and branches supply the small intestine?

Answer 9

From the Celiac trunk:
- common hepatic (duodenum)

From the Superior Mesenteric Artery:

• intestinal arteries (15-18 branches supply small intestines)
• anterior and posterior inferior pancreaticoduodenal aa (duodenum)
• ileocolic (terminal ileum)

Question 10

Which arteries and branches supply the large intestine?

Answer 10

From Superior Mesenteric Artery:

• ileocolic (cecum)
• right colic a (ascending)
• middle colic a (transverse)

From Inferior Mesenteric Artery:

• left colic (descending)
• sigmoid a (sigmoid colon)
• superior rectal a (rectum)

Question 11

What are the three SNS ganglia that supply abdominopelvic viscera?

Answer 11

• celiac
• superior mesenteric
• inferior mesenteric

Question 12

What is the difference between abdominopelvic splanchnic nerves and pelvic splanchnic nerves?

Answer 12

Abdominopelvic splanchnic nerves are SNS, consist of:

• greater splanchnic (T5-9/10)
• lesser splanchnic (T9-10/11)
• least splanchnic (T12)
• lumbar splanchnic (L1-3)

Pelvic splanchnic nerves are PNS, from S2-4

Question 13

What are the 4 types of abdominopelvic splanchnic nerves?

Answer 13

Greater splanchnic (T5-10)
Lesser splanchnic (T9-11)
Least splanchnic (T12)
Lumbar splanchnic (L1-3)

Question 14

What are the three nervous systems that innervate the abdominopelvic viscera?

Answer 14

PNS (parasympathetic nervous system)

• CNX Vagus via doral motor nucleus of vagus in medulla: abdominopelvic viscera to left colic / splenic flexure
• S2-4: abdominopelvic viscera below left colic / splenic flexure

SNS (sympathetic nervous system)

• via abdominopelvic splanchnic nerves, synapsing at the celiac, superior mesenteric and inferior mesenteric plexi
• greater splanchnic (T5-10)
• lesser splanchnic (T9-11)
• least splanchnic (T12)
• lumbar splanchnic (L1-3)

ENS (enteric nervous system)

• intrinsic nervous system of GIT
• a division of the ANS
• can operate independently of central nervous system
• neurons in myenteric and submucosal plexi
• myenteric plexi: between layers of muscularis
• submucosal plexi: in submucosal layer

Question 15

What are the ENS plexi and where are they located?

Answer 15

Myenteric: between layers of muscularis in GIT wall
Submucosal: in submucosal layer in GIT wall

Question 16

Which 4 nerves innervate the anterolateral abdominal wall?

Answer 16

Thoracoabdominal nerves (T7-11)
- branches of intercostal nerves 7-11

Subcostal nerve (T12)

Iliohypogastric nerve (L1 via lumbar plexus)

Ilioinguinal nerve (L1)