Gastrointestinal Arteries and Nerves - Ashley Flashcards Preview

Gastrointestinal I > Gastrointestinal Arteries and Nerves - Ashley > Flashcards

Flashcards in Gastrointestinal Arteries and Nerves - Ashley Deck (30)
Loading flashcards...
1

Mneumonic for where structures enter the abdomen

I ate 10 eggs at 12
IVC - 8
Esophagus - 10
Aorta - 12

2

Abdominal aorta

Begins at T12
Retroperitoneal
Terminates at L4
-bifurcates into L and R common iliac arteries

3

Where does the thoracic duct drain?

Into the LEFT subclavian vein

4

AAA

Balloon like dilation of aorta when media (usually) weakens
Usually below renal arteries and above aortic bifurcation
Primarily due to atherosclerosis

5

Unpaired branches of aorta

Supply GI structures and branch anteriorly
-Celiac trunk, superior mesenteric, inferior mesenteric, median sacral a.

6

Paired branches of aorta

Supply non-GI structures and branch laterally
-inferior phrenic, testicular/ovarian, suprarenal, renal, common iliac

7

Innervation of abdominal viscera

Nerve plexi
Networks containing symp, parasymp, afferent nerve fibers and respective ganglia
Some interconnected
Named for nearest branch of aorta
-celiac, sup mes, inf mes

8

Where do presynaptic fibers aries from?

Gray matter of spinal cord at T5-L2, L3
Conveyed via abdominopelvic splanchnic nerves

9

What is the main source of presynaptic sympathetic fibers to abdominal viscera?

Greater splanchnic
T5-9

Others contribute - Lesser (T10-11) and Least (T12)

10

Pelvic splanchnic n.

Derive from anterior rami of S2-4
NOT associated with sympathetics
Innervation beyond left colic flexure

11

What provides innervation up to left colic flexure?

Ant and post vagal trunks
-convey presynaptic and visceral afferent reflex fibers to abdominal aortic plexuses and periarterial plexuses

12

2 Principle plexuses of enteric nervous system

1. Myenteric plexus - motility
2. Submucosal plexus - secretions, blood flow, absorption

13

Celiac trunk

3 branches - L gastric, splenic, common hepatic

14

Common hepatic a. branches into these two arteries?

1. Proper hepatic --> R gastric --> R and L hepatic
2. Gastroduodenal a. --> R gastro-omental and superior pancreaticoduodenal

15

2 branches of splenic artery?

Short gastric
L gastro-omental

16

What is contained within the hepatoduodenal ligament?

Portal triad
-bile duct, proper hepatic artery, portal vein

17

What forms the bile duct?

Common hepatic duct (liver)
Cystic duct (gallbladder)

18

Blood supply to liver?

Proper hepatic a. - oxygenated --> divides into L and R hepatic
Portal v. - deoxygenated, nutrient rich blood

19

Portal vein is formed by union of?

Splenic v and superior mesenteric v

20

What drains the liver?

Hepatic vv.

21

Blood supply to pancreas

Celiac a.

Superior mesenteric a. - gives off branches to 'free'small intestine
**Emerges from aorta posterior to the neck of the pancreas
-enters THE mesentery and runs between layers

22

Superior mesenteric artery branches

1. Inferior pancreaticoduodenal a.
2. Jejunal a. - long vasa recta, simple arcades
3. Ileal a. - short vasa recta, complex arcades

23

What makes ileum different?

Short vasa recta, complex arcades
Less vascularized
Fewer plicae circulares are shorter or absent

24

Superior mesenteric artery branches to large intestine

Middle colic a.
Right colic a
Marginal a.
Ileocolic a.

25

What joins to form the portal vein

Superior mesenteric vein
Splenic vein
--posterior to the neck of the pancreas

26

Inferior mesenteric artery

Supplies derivatives of the hind gut (distal 1/3 of transverse colon to upper portion of rectum)
Branches - L colic, Sigmoid a, superior rectal a, marginal a

27

Internal hemorrhoids

Prolapse and breakdown of muscularis mucosae
No pain

28

External hemorrhoids

Thromboses in veins of external rectal venous plexus from increased intra-abdominal pressure
Innervated by inferior anal nerves ---PAIN

29

Causes of ischemic bowel

1. Embolus - blood clot form heart or main vessels block an artery supplying the intestine
2. Arterial thrombosis - a. become narrowed due to atherosclerotic disease
3. Venous thrombosis - v. carrying blood away form intestines may become blocked by blood clots

30

Volvulus most often occurs where?

In the sigmoid portion of the large intestine