Posterior Abdominal Wall

Question 1

Which of these vessels are directly associated with the abdominal autonomic plexuses?

Answer 1

Celiac trunk, superior and inferior mesenteric aa.

Question 2

From which vertebral levels does the sympathetic input to these plexuses arise?

Answer 2

T5 through L4.

Question 3

What specific structures deliver the sympathetic input into these plexuses?

Answer 3

Thoracic and lumbar splanchnic nn.

Question 4

By what structure(s) does the parasympathetic input to these plexuses arrive?

Answer 4

The vagus (for celiac and superior mesenteric plexuses) and the pelvic splanchnic nn. For the inferior mesenteric plexus.

Question 5

How far does parasympathetic input from the vagus extend along the G.I.T.?

Answer 5

To the mid transverse colon.

Question 6

Where does parasympathetic input for pelvic organs arise?

Answer 6

S2 through S4.

Question 7

How many lobes are there in each kidney?

Answer 7

5 lobes (segments) per kidney

Question 8

How many segmental branches are there from each renal artery?

Answer 8

Five segmental aa. (one per kidney lobe/segment).

Question 9

Name the 3 sites where kidney stones are likely to become impaled and cause pain
along the length of the ureter.

Answer 9

1. Where pelvis narrows to ureter proper; 2. where ureter bends over common iliac into pelvis; 3. where ureter pierces the bladder wall.

Question 10

At what point does the ureter cross into the pelvis?

Answer 10

At the pelvic brim (entrance into true pelvis).

Question 11

Name a specific anatomical relationship the ureter has with the common iliac a.

Answer 11

At the bifurcation of the common iliac into the external and internal iliac aa.

Question 12

Where are the suprarenal glands located?

Answer 12

On the superior pole of each kidney (retorperitoneal).

Question 13

How can they be identified on the basis of shape?

Answer 13

The left is semilunar in shape while the right is more pyramidal.

Question 14

Why are the suprarenal glands so richly vascularized?

Answer 14

They are endocrine glands

Question 15

What is unusual about the sympathetic innervation of these organs?

Answer 15

The preganglionic sympathetic fibers extend into the organ and synapse in the medulla (central core). Generally preganglionic sympathetic fibers synapse in a distant (paravertebral/prevertebral) ganglion.

Question 16

List the muscles that comprise the posterior abdominal wall.

Answer 16

Quadratus lumorum, iliacus and psoas major.

Question 17

What is the innervation of each muscle?

Answer 17

Psoas and quadratus lumborum = ventral rami of L1-3; iliacis = femoral n.

Question 18

What is the function of each muscle?

Answer 18

Quadratus lumborum: stabilizes R12 during inspiration as well as laterally flexing the trunk; the combined iliopsoas: flexes the hip on the trunk.

Question 19

Which two ligaments of the diaphragm are formed by thickenings of the fascia over the
musculature of the posterior abdominal wall.

Answer 19

The medial and lateral arcuate ligaments.

Question 20

Identify the muscles involved in each ligament.

Answer 20

Fascia over the psoas major thickens to form the medial arcuate ligament; facsia of the quadratus lumborum thickens to form the lateral arcuate ligament.

Question 21

Which part of the 3 parts of the diaphragm arise from these ligaments?

Answer 21

The lumbar portions of the diaphragm.

Question 22

What are the other two components comprising the diaphragm.

Answer 22

The sternal and costal portions.

Question 23

Identify two triangles formed by muscle deficiency in the diaphragm.

Answer 23

The sternocostal and lumbocostal triangles.

Question 24

Which triangle allows a structure to traverse it?

Answer 24

The sternocostal - the superior epigastric a. passes through it.

Question 25

Which of the two diaphragmatic crura is longest?

Answer 25

The right crus.

Question 26

To which vertebral levels does each diaphragmatic crus extend inferiorly?

Answer 26

The left drus extends to L1/2; the right crus extends to L3/4

Question 27

Which crus of the diaphragm forms a sling around the esophagus?

Answer 27

The right crus.

Question 28

List the various openings in the diaphragm, their vertebral level, and what traverses them.

Answer 28

Caval: T8 - iunferior vena cava; esophageal: T10 - esophagus & vagus nn.; and aortic: T12 - aorta.

Question 29

Which ventral rami contribute to the lumbar plexus?

Answer 29

L1 through L4.

Question 30

What nerves are formed by the lumbar plexus?

Answer 30

Iliohypogastic, ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, obturator, lumbosacral trunk.

Question 31

What is the function of each nerve formed by the plexus?

Answer 31

Iliohypogastic, ilioinguinal, genitofemoral, lateral femoral cutaneous: sensory to cutneous regions named; femoral: motor to the muscles of the anterior compartment of the thigh; obturator: motor to the muscles of the medial compartment of the thigh; lumbosacral trunk: takes innervation from lumbar plexus down into the sacral plexus.

Question 32

Be able to correctly orient the various branches of the lumbar plexus with its landmark- the psoas major muscle.

Answer 32

Lateral to the psoas major: iliohypogastic, ilioinguinal, lateral femoral cutaneous and femoral on surface of the psoas: genitofemoral; medial to the psoas: obturator, and lumbosacral trunk.

Question 33

Know the 9 regions of the abdomen and those which contain specific clinically
relevant organs.

Answer 33

Right hypochondriac: liver; epigastric: stomach; left hypochondriac: spleen; right lateral: asecnding colon; umbilical; left lateral: descending colon; right iliac (inguinal): appendix; hypogastric; left iliac (inguinal): sigmoid colon.