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Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
Page 1 of 6
Renal Gross Anatomy Lecture 1
I. Bony Parts of the Post. Abdominal Wall
1. median plane - bodies, intervertebral discs, and transverse processes of the 5 lumbar
vertebrae
2. laterally - from the twelfth pair of ribs above to the pelvic brim below; divided into
upper and lower parts by the iliac crests. The region of the abdomen between the iliac
crests and pelvic brim is the pelvis major.
II. Muscles
1. Psoas major
a. arises from the sides of vertebral bodies, transverse processes, and intervertebral
discs of TV12 and all the lumbar vertebrae
b. fibers run downward and laterally to enter the thigh behind the inguinal ligament and
insert into lesser trochanter of femur
c. enclosed in a fibrous sheath derived from the lumbar fascia which is thickened above
to form the medial arcuate ligament of the diaphragm
d. flexes the thigh at the hip joint on the trunk; if the thigh is fixed, it flexes the trunk on
the thigh, as in sitting up from lying position
e. nerve supply: lumbar plexus
2. Psoas minor
a. either absent (40-50%) or insignificant [ the other 3 that are sometimes absent are:
upper limb – palmaris longis; lower limb – plantaris; anterior abd. wall
pyramidalis]
b. when present, its narrow tendon may be mistaken for the genitofemoral nerve on
the surface of the psoas major; the belly is small and the tendon is very long
3. Quadratus lumborum
a. quadrate but not rectangular, for its lateral border is oblique, a landmark when
exposing the kidney from behind
b. lies alongside the vertebral column; lateral to the psoas major
c. origin - lower lumbar vert. ; insertion - iliac crest
d. fibers run upward and medially and insert into the lower border of 12th rib and
transverse processes of upper 4 lumbar vertebrae
e. anterior surface covered by the lumbar fascia which is thickened to form lateral
arcuate ligament above and iliolumbar ligament below
Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
Page 2 of 6
f. fixes the 2th rib during inspiration; depresses the 12th rib during forced expiration;
laterally flexes vertebral column (trunk) on same side
g. nerve supply: lumbar plexus
4. Transversus abdominis
a.
b.
c.
d.
becomes aponeurotic at lateral border of quadratus lumborum
helps form a sheath for the deep back muscles
action: compresses abdominal contents
nerve supply: lower 6 thoracic nerves; iliohypogastric nerve (L1); ilioinguinal nerve
(L1)
5. Iliacus
a. occupies the iliac fossa
b. joins lateral side of psoas major tendon to be inserted into lesser trochanter of femur;
combined muscles referred to as iliopsoas
c. action: together with the psoas, most powerful flexor of the thigh
d. flexes the thigh on the trunk; if the thigh is fixed, it flexes the trunk to the thigh, as in
sitting up from lying position
e. nerve supply: femoral nerve
6. Diaphragm – forms the upper portion of the posterior abd. wall
III. Fascial Lining [N236]
- one continuous layer of connective tissue that lies between the parietal peritoneum and
the muscles; continuous below with a similar fascial layer lining the pelvic walls; named
according to the structure it overlies: diaphragmatic fascia, transversalis fascia, psoas
fascia, quadratus lumborum fascia, fascia iliaca
[-abdominal blood and lymph vessels lie within this fascial lining, whereas the principal
nerves lie outside the fascia. This fact is important in the understanding of the femoral
sheath which is simply a downward prolongation of the fascial lining around the femoral
vessels and lymphatics, for about 4 cm into the thigh, behind the inguinal ligament. Since
the femoral nerve lies outside the fascial lining, it has no sheath.]
IV. Great Vessels of the abdomen
1. Abdominal aorta (runs from TV12 – LV4)
Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
Page 3 of 6
a. enters the abdomen in the median plane at the disc between TV12 and LV1
b. branches to:
1. GIT and 3 unpaired glands (liver, pancreas, spleen)
a. celiac trunk- arises at level of disc TV12-LV1
b. sup. mesenteric a.-prevents ascent of left renal vein
c. inf. mesenteric a.-arrests ascent of horseshoe kidney
2. 3 paired glands (kidneys, suprarenal glands, gonads)
a. suprarenal aa. (hard to find)
b. renal aa.
c. testicular (ovarian) aa.
3. roof and walls of the abdomen
a. inf. phrenic aa. -the most superior of these, supplies under surface of diaphragm
b. lumbar aa. – 4 pairs but 5 LV (the 5th pair comes from the internal iliac a.)
c. median sacral a. – unpaired, was once large during development; the tiny
"continuation" of the aorta.
c. termination - in front of LV4 by bifurcating into the right and left common iliac aa;
each common iliac a.-bifurcates into an internal and an external iliac a.; external iliac a.
(main trunk to the thigh) runs on the psoas to the midinguinal point where its changes its
name to femoral a.; 2 branches arise from the external iliac a. just before it passes behind
the inguinal ligament - the inf. epigastric and deep circumflex iliac aa. (anastomose with
iliolumbar aa. from int. iliac aa. on iliac crest)
2. Inferior vena cava (runs from LV5 – TV8)
a. largest vein in the body, found on right side of abd. aorta; formed by the right and
left common iliac veins
b. begins in front of LV5 below the aortic bifurcation & behind the right common iliac
a.
c. pierces the central tendon of the diaphragm at the level of TV8 to join the right
atrium of the heart
d. extends across 8 vertebrae and is about twice the length of the abdominal aorta.
e. Tributaries draining
1. blood from the GIT, after circulating in the liver leaves it via the right and left hepatic
veins (most superior tributaries) to enter the last part of the IVC
2. 3 paired glands - the right suprarenal, right renal, and right testicular (ovarian) veins
enter the IVC; the left renal vein drains all three organs on the left side.
Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
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3. veins of body wall- 4 lumbar vv. irregularly linked together on each side by an
ascending lumbar v.(joins with the subcostal vein which is found in the neurovascular
bundle inferior to the 12th rib), which lies in front of the lumbar transverse processes;
ascending lumbar vein becomes the azygos v. on the right and the hemiazygos v. on the
left in the thorax; median sacral v. - ends in the left common iliac v.
4. pregnant women are asked to lay on their left side to relieve the pressure on the IVC
and increase the venous return to the heart.
V. Lymphatics
1. preaortic nodes (anterior surface of the aorta) lie around origin of celiac, SMA, and
IMA --> drain the GIT from lower 3rd of esophagus to upper half of anal canal, spleen,
pancreas, gall bladder, liver; efferent vessels form the intestinal trunk
2. right and left paraaortic nodes (on the side of the aorta) drain the kidneys, suprarenals,
testes, ovaries, uterine tubes, and uterine fundus; efferent vessels form the right and left
lumbar trunks; and lumbar trunks drain into the cisterna chyli (enlarged 1st portion of the
thoracic duct; not always present) - located in front of LV 1&2 to the right of the aorta
3. intestinal lymph trunk and lumbar lymph trunk form the thoracic duct which drains
into the left subclavian and left internal jugular vv. Junction
4. on the right: the junction of the right subclavian and right internal jugular forms the
right lymphatic duct which drains the right side of head and neck and right upper limb
VI. Lumbar Plexus
1. formed by the ventral rami of L1, L2, L3, and upper half of L4.
2. first ramus is joined by a branch of T12.
3. lower half of L4 joins L5 near the anterior border of the ala of the sacrum to form the
lumbosacral trunk which is the nerve supply to the lower limbs
4. branches:
a. iliohypogastric n. (L1) – supplies the hypogastric area
b. ilioinguinal n. (L1) – located on the surface of the spermatic cord
c. genitofemoral n. (L1, L2)
1. femoral branch – (sensory) pierces the fascia lata and supplies the skin of the
femoral triangle
2. genital branch (motor) supplies the cremaster muscle and traverses the
inguinal canal to end in the skin of scrotum
Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
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a. (cremasteric reflex – stroke the inner surface of thigh causes cremaster muscle to
contract which causes the scrotum on that side to rise)
d. lateral (femoral) cutaneous n. (L2, L3) – supplies the skin on lateral aspect of thigh
e. femoral n. (post. division of L2, L3, L4) – supplies the anterior muscles of the thigh
which flex the thigh and extend the knee
f. obturator n. (ant. division of L2,L3, L4) – supplies the medial muscles of the thigh
which are the adductors
To identify the nerves, use the psoas major as a landmark and where they exit
lateral aspect – iliohypogastric, ilioinguinal, lat cutaneous, femoral
anterior aspect – genitofemoral
medial aspect – obtuator which exits the obturator foramen
VII. Abdominal autonomics
1. Sympathetic trunk
a. enters from the thorax behind the medial arcuate ligament and follows faithfully the
medial border of the psoas
b. passes into the pelvis behind the common iliac vessels.
c. right trunk is concealed by IVC and crossed by the right renal a.
d. left trunk is crossed by the left renal vessels, left testicular a., & inferior mesenteric a.
e. each trunk receives a white ramus from each of the upper 2 (or 3) lumbar nerves (L1,
2, [3]) and sends one or more gray rami to each of the 5 lumbar nerves to be
distributed with nerves to somatic structures
f. 4 postganglionic lumbar splanchnic nerves (visceral branches) run medially to the
intermesenteric and superior hypogastric plexuses to be distributed largely with
blood vessels to viscera.
2. Prevertebral plexuses
a. Celiac plexus (solar plexus)
1. connects celiac ganglia; encircle the celiac trunk; branches radiate like the
rays of the sun
2. each celiac ganglion lies behind the peritoneum, between the celiac trunk and
the suprarenal gland and, therefore, on the crus of the diaphragm; IVC largely
conceals the right celiac ganglion, while the pancreas and splenic artery
largely conceal the left one; joined by the greater splanchnic n. at its upper
part and by the lesser splanchnic n. at its lower part
b. Intermesenteric and superior hypogastric plexuses
1. celiac plexus reinforced by the lumbar splanchnics
c. Renal plexus
1. an offshoot of the celiac plexus
2. joined by the lowest splanchnic nerve
3. Parasympathetic nerves
Renal #4
Mon, 03/17/03, 1pm
Dr. Rosales
Brian Anderson
Page 6 of 6
a. fibers of both vagus nn., via a large branch of the posterior vagal trunk, pass
through the celiac plexus to be distributed with arteries (celiac, superior
mesenteric, and renal) to the abdominal viscera; control the gut as far as the left
colic flexure
b. fibers of pelvic splanchnic nerves (S2-4) ascend from the pelvis in the
hypogastric plexus to be distributed with the inferior mesenteric a. to the gut;
innervate the descending colon, sigmoid colon, rectum, and internal anal
sphincter