Lecture 7; Anatomy of the gut, ANS and blood supply

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Describe what orientation arteries come off the aorta;

Answer 12

Anterior aspect only

Question 13

Describe the three major arteries that come off the aorta in regards to the abdomen;

Answer 13

T12; Celiac trunk

L1; Superior mesenteric artery

L3; Inferior mesenteric artery

Question 14

Describe the neurovascular supply of the foregut;

Answer 14

Arterial; Branches of the coelic axis (T12)

Venous drainage; Portal vein (NO CELIAC VEIN)

Nerve plexus; Coeliac PLexus (T12)

Lymphatics; Pre-aortic nodes (T12)

Question 15

What are some important notes on the foregut;

Answer 15

• Digestive system starts in oral cavity
• Spleen is NOT foregut
• Pain is referred to the EPIGASTRIC region

Question 16

Whats some notable surface anatomy relations to the stomach;

Answer 16

Generally; Epigastric, to left of midline

Oesophagus = Costal cartilage 7/8

Fundus = Ribs 5/6

Pylorus ~L1

Question 17

What does the inner lining of the stomach contain?

Answer 17

Rugae to increase SA and motility

Question 18

Describe the blood supply to the various stomach regions;

Answer 18

Lesser curviture = Left gastric (celiac trunk) and right gastric (common hepatic) anastomose

Greater curviture = Left gastro-omental (splenic) and right gastro-omental (Gastro-duodenal (from common hepatic)) anastomose

Fundus = Short gastric (Splenic)

Question 19

Where does the omentum hang off?

Question 20

Describe the passage of the duodenum in relation to other structures;

Question 21

Describe which parts of the duodenum are peritoneal and the change in neurovascular supply;

Answer 21

1st part = intraperitoneal

2,3,4 = Reteroperitoneal

Halfway aong duodenum it transitions to midgut origin therefore blood, nerves, lymphatics change.

Question 22

Describe the neurovacular supply of the duodenum;

Answer 22

Art;

Sup. half; Superior pancreaticoduodenal branches from duodenal art. -> Celiac trunk

Inf. half; Inferior pancreaticoduodenal branches from SMA

Nerve;

Sup; Celiac plexus @ T12

Inf; SMA @ L1

Venous;

Sup; Direct to portal vein

Inf; Superior mesenteric vein

Lymp;

Sup; Pre-aortic celiac nodes @ T12

Inf; Pre-aortic Sup. Mesenteroc nodes @ L1

Question 23

Whats the neurovascular supply of the midgut;

Answer 23

Art. = SMA @L1

Venous; SMV

Nerve; SMP @L1

Lymph; Pre aortic nodes @L1 (SMN)

Question 24

Where is pain from the midgut referred to?

Answer 24

Umbillical region

Question 25

Write some notes on the midgut SI;

Question 26

How can you use the arterial pattern to identify the Jejunum and ilium;

Answer 26

Jejunum; 1 or 2 aracades with long branches Ilium; More arcades with many small branches

Question 27

Describe the neurovascular supply to the jejunum and ilium;

Question 28

Where does the midgut to hindgut transition occur?

Question 29

Whats the function of the large intestine?

Question 30

What are some gross features of the large intestine;

Question 31

Describe the surface anatomy in relation to LI;

Question 32

Describe the arterial supply of the large intestine;

Answer 32

Midgut/ SMA @ L1 - Ceacal and appendicular art, from ilioceacal - Ascending colon = Right colic a. - Proximal 2/3 trans colon = middle and marginal a. Hindgut/IMA @ L3 = - Distal 1/3 trans colon = Marginal and left colic. a - Descending colon = Left colic a. - Sigmoid colon = Sigmoid art. marginal art = anastamotic point b/w sup and inf mesenteric art.

Question 33

Describe the neurovascular supply of the hindgut;

Answer 33

Art. = IMA @L3 Venous; IMV Nerve; IMP @L3 Lymph; Pre aortic nodes @L3 (IMN)

Question 34

Where does the rectum start?

Question 35

Describe the transition to the anal canal from the rectum;

Answer 35

Pierces pelvic diaphragm at tip of coccyx to become anal canal

Question 36

Describe the peritoneal nature of the anal canal;

Answer 36

- Sup. 1/3 = Viscera; peritoneum on Ant. and Post. - Middle 1/3 = Peritoneum on ant. only - Inf 1/3 = Infraperitoneal

Question 37

Describe the art. supply of the anus;

Answer 37

Sup. rectal = IMA @ L3 (majority) Middle = Branch of internal iliac Inferior rectal = Branch of pudendal

Question 38

Describe the portal system anastomoses that occurs from the rectal veins;

Question 39

Describe the ANS of the gut;

Question 40

Whats an important note about the PSNS to the gut?

Question 41

Describe the sympathetic supply to the gut regions;

Answer 41

Foregut -\> Celiac plexus -\> Greater splanchnic (T5-9) Midgut-\>SMP-\>Lesser splanchnic (T10-11) Hindgut-\>IMN & Sup. hypogastric-\> Lumbar/sacral splachnic (L1-2)

Question 42

Describe how the pain of an appendicitis varies;

Answer 42

- Inflammed appendix - Afferent sympathetics refer back to T10-11 dermatome (Broad pain around the umbilical region) - Appendix inflammes and englarges touching the parietal peritoneum on the body wall (Somatic sensory supply) - Pain now felt as acute and localised to R. inguanal