Posterior Abdominal Wall Flashcards
Which of these vessels are directly associated with the abdominal autonomic plexuses?
Celiac trunk, superior and inferior mesenteric aa.
From which vertebral levels does the sympathetic input to these plexuses arise?
T5 through L4.
What specific structures deliver the sympathetic input into these plexuses?
Thoracic and lumbar splanchnic nn.
By what structure(s) does the parasympathetic input to these plexuses arrive?
The vagus (for celiac and superior mesenteric plexuses) and the pelvic splanchnic nn. For the inferior mesenteric plexus.
How far does parasympathetic input from the vagus extend along the G.I.T.?
To the mid transverse colon.
Where does parasympathetic input for pelvic organs arise?
S2 through S4.
How many lobes are there in each kidney?
5 lobes (segments) per kidney
How many segmental branches are there from each renal artery?
Five segmental aa. (one per kidney lobe/segment).
Name the 3 sites where kidney stones are likely to become impaled and cause pain
along the length of the ureter.
- Where pelvis narrows to ureter proper; 2. where ureter bends over common iliac into pelvis; 3. where ureter pierces the bladder wall.
At what point does the ureter cross into the pelvis?
At the pelvic brim (entrance into true pelvis).
Name a specific anatomical relationship the ureter has with the common iliac a.
At the bifurcation of the common iliac into the external and internal iliac aa.
Where are the suprarenal glands located?
On the superior pole of each kidney (retorperitoneal).
How can they be identified on the basis of shape?
The left is semilunar in shape while the right is more pyramidal.
Why are the suprarenal glands so richly vascularized?
They are endocrine glands
What is unusual about the sympathetic innervation of these organs?
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.
List the muscles that comprise the posterior abdominal wall.
Quadratus lumorum, iliacus and psoas major.
What is the innervation of each muscle?
Psoas and quadratus lumborum = ventral rami of L1-3; iliacis = femoral n.
What is the function of each muscle?
Quadratus lumborum: stabilizes R12 during inspiration as well as laterally flexing the trunk; the combined iliopsoas: flexes the hip on the trunk.
Which two ligaments of the diaphragm are formed by thickenings of the fascia over the
musculature of the posterior abdominal wall.
The medial and lateral arcuate ligaments.
Identify the muscles involved in each ligament.
Fascia over the psoas major thickens to form the medial arcuate ligament; facsia of the quadratus lumborum thickens to form the lateral arcuate ligament.
Which part of the 3 parts of the diaphragm arise from these ligaments?
The lumbar portions of the diaphragm.
What are the other two components comprising the diaphragm.
The sternal and costal portions.
Identify two triangles formed by muscle deficiency in the diaphragm.
The sternocostal and lumbocostal triangles.
Which triangle allows a structure to traverse it?
The sternocostal - the superior epigastric a. passes through it.
Which of the two diaphragmatic crura is longest?
The right crus.
To which vertebral levels does each diaphragmatic crus extend inferiorly?
The left drus extends to L1/2; the right crus extends to L3/4
Which crus of the diaphragm forms a sling around the esophagus?
The right crus.
List the various openings in the diaphragm, their vertebral level, and what traverses them.
Caval: T8 - iunferior vena cava; esophageal: T10 - esophagus & vagus nn.; and aortic: T12 - aorta.
Which ventral rami contribute to the lumbar plexus?
L1 through L4.
What nerves are formed by the lumbar plexus?
Iliohypogastic, ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, obturator, lumbosacral trunk.
What is the function of each nerve formed by the plexus?
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.
Be able to correctly orient the various branches of the lumbar plexus with its landmark- the psoas major muscle.
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.
Know the 9 regions of the abdomen and those which contain specific clinically
relevant organs.
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.
