Branching of Abdominal Aorta & Origins of Vena Cava & Azygous Veins

Question 1

where does the abdominal aorta run

Answer 1

follows roof of abdomen with caudal vena cava to the right

Question 2

what are the categories of branches of the abdominal aorta

Answer 2

visceral (unpaired and paired) and parietal branches

Question 3

where does the abdominal aorta terminate and how does it continue

Answer 3

below last lumbar vertebrae

continues as median sacral artery (tail) 4

Question 4

what are the visceral branches of the abdominal aorta

Answer 4

1. celiac artery: stomach, pancreas, spleen (foregut)
2. cranial mesenteric artery: jejenum, ascending colon (midgut)
3. renal arteries
4. testicular or ovarian arteries (kidneys)
5. caudal mesenteric artery (descending colon, hindgut)

Question 5

what are the parietal branches of the abdominal aorta

Answer 5

1. phrenico-abdominal trunk –> caudal phrenic aa and cranial abdominal aa
2. 7 paired lumbar aa
3. deep circumflex iliac aa
4. external iliac aa
5. internal iliac aa

Question 6

identify the branches of the abdominal aorta and whether they are parietal or visceral and what they supply

Answer 6

Question 7

what does the external iliac aa give rise to

Answer 7

femoral aa (hindlimbs)

deep femoral aa (adductor muscles of thigh)

pudendoepigastric trunk (ventral lateral abdominal wall and groin)

Question 8

what does the internal iliac aa give rise to

Answer 8

caudal gluteal aa (muscles assocaited lumbosacral region)

internal pudendal aa (pelvic viscera)

Question 9

what does the deep circumflex iliac aa supply

Answer 9

caudal abdominal, flank and cranial thigh

Question 10

how does the cranial vena cava form in dogs, cat, pig

Answer 10

just before the thoracic inlet (cranial boundary of thoracic cavity)

Question 11

how does the cranial vena cava form in ruminants and horses

Answer 11

Question 12

how do the external jugular veins form

Answer 12

the maxillary vein and the lingofacial vein unite at the angle of the jaw to form the external jugular veins

Question 13

what is the venous drainage of the forelimb, neck and shoulders (cranial aspect)

Answer 13

Question 14

what are other veins of that drain to the external jugular and subclavian veins

Answer 14

Question 15

how is the azygous vein formed

Answer 15

union of the first few lumbar veins

Question 16

where does the azygous vein pass through the diaphragm

Answer 16

aortic hiatus

Question 17

what does the azygous vein drain

Answer 17

intercostal veins (except most cranial) and venous plexus within vertebral canal

Question 18

what does the azygous vein unite with

Answer 18

cranial vena cava in the dog

or empties independently into right atrium in horse

Question 19

what occurs if the left azygous vein persists

Answer 19

in the fetus the left azygous vein drops out and in dogs, horses only the right persists

if it persists it empties into right atrium via coronary sinus in the pig and ruminant

Question 20

how does the left azygous vein drain in the bovine

Answer 20

travelling on left side

joining coronary groove –> right atrium via coronary sinus

Question 21

how does the caudal vena cava originate

Answer 21

internal iliac vein, external iliac vein, deep circumflex iliac vein, ovarian/testicular vein, renal vein

Question 22

name the veins that contribute to venous return of caudal vena cava

Answer 22

r. external iliac vein
r. internal iliac vein
r. deep circumflex iliac vein
r. ovarian/testicular vein
r. renal vein

hepatic vein

hepatic portal vein

r. azygous vein
r. internal thoracic vein