Download renal plexus

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Anatomy Exam 2 Outline
Lecture 11 – Posterior Abdominal Viscera
1. Suprarenal (Adrenal) glands
a. Between superomedial aspects of kidneys and diaphragm
b. Surrounded by connective tissue containing perinephric fat
c. Enclosed by renal fascia attaching them to the crura of the diaphragm
i. Major attachment of the suprarenal glands is to the diaphragmatic crura rather than the
kidneys
d. Thoracoabdominal diaphragm
i. Right crus
1. Originates off L1-L3/4 bodies, IV discs
2. Larger than left crus
3. Forms esophageal hiatus
ii. Left crus
1. Origin  L1-L2/3, bodies, IV discs
e. The suprarenal glands are separated from the kidneys by a thin septum (part of renal fascia)
i. In chronic renal failure, kidney can be removed from donor without damaging suprarenal gland
because of the weak septum of renal fascia that separates the kidney from the gland
f. Each gland has a hilum where veins and lymphatic vessels exit the gland
g. Arteries and nerves enter the glands at multiple sites
h. On CT, they have a triangular shape, sitting on top of the kidneys
i. Shape and relationships of the glands differ between R and L
j. Crescent-shaped Left gland
i. Medial to superior half of the left kidney
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k.
l.
m.
n.
o.
ii. Near the spleen, stomach, pancreas, left crus of the diaphragm
Pyramidal right gland
i. More apical relative to L
ii. Lies anterolateral to the R crus of the diaphragm near the IVC and liver
Suprarenal arteries
i. Lots of blood supply necessary to support endocrine function
ii. 50-60 suprarenal a branches penetrate the capsule
iii. Suprarenal arteries arise from 3 sources
1. Superior suprarenal arteries  from inferior phrenic arteries
2. Middle suprarenal arteries  from abdominal aorta
3. Inferior suprarenal arteries  from renal arteries
Suprarenal veins
i. Venous drainage through large suprarenal veins
1. Short right suprarenal vein  IVC
2. Longer left suprarenal veins  joined by inferior phrenic vein  left renal vein
ii. Close proximity of the IVC to R suprarenal vein increases possibility of damage of IVC in R
adrenalectomy
Lymphatics
i. Suprarenal lymphatic vessels  from a plexus deep to the capsule of the gland and from plexus
in its medulla
1. Lymph passes to the lumbar lymph nodes
Suprarenal gland components
i. Capsule  tough fibroelastic covering of the adrenal gland
ii. Cortex  controls electrolyte and water distribution in the body, maintains proper
carbohydrate balance
1. Derives from mesoderm
2. Three zones with different cell arrangement
a. Zona glomerulosa: produces aldosterone
b. Zona fasciculate: produces cortisol
c. Zona reticularis: produces androgens
iii. Medulla  produces epinephrine and norepinephrine
1. Activates the body to fight/flight in response to trauma
2. Derives from neural crest cells associated with sympathetic nervous system
3. Chromaffin cells of the medullar are related to sympathetic ganglion (postsynaptic
neurons)
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p. Nerve supply of suprarenal glands
i. Supply of suprarenal glands is from celiac plexus and abdominopelvic (greater, lesser, least)
splanchnic nerves
ii. Vasomotor innervation only for cortex
iii. Sympathetic innervation to medulla
iv. Myelinated presynaptic sympathetic fibers derived from intermediolateral cell column, or lateral
horn, T10-L1
1. Travel through paravertebral and prevertebral ganglia without synapsing and distribute
to chromaffin cells in suprarenal medulla
q. Chromaffin cells secrete catecholamines (epi and norepi) into the bloodstream
i. Activate the body to fight-or-flight in response to acute stress
ii. Increase heart rate and blood pressure; dilate bronchioles
r. Adrenogenital syndrome
i. Congenital adrenal hyperplasia
ii. Excessive quantities of androgens cause intense masculinizing effects throughout the body
iii. Females
1. Growth of beard, deeper voice
2. Baldness, masculine distribution of hair
3. Growth of clitoris to resemble a penis
iv. Prepubertal male
1. Growth of beard, deeper voice, masculine distribution of hair
2. Rapid development of sex organs
v. Adult male
1. Difficult to make a diagnosis
s. HPA axis
i. Stress response components mediated by hypothalamic-pituitary-adrenal axis (HPA axis)
ii. Stress induces nerve cells in the hypothalamus to produce and release corticotropin-releasing
factor
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iii. CRF transported to anterior pituitary gland; CRF stimulates production of prooplomelano-cortin
serving as a basis for other stress related hormones, including adrenocorticotropic hormone
iv. ACTH stimulates cells of adrenal glands to produce and release stress hormone cortisol
t. Adrenocorticoid hyperfunction (Cushing’s syndrome)
i. Suprarenal cortical hyperplasia
1. Moon shaped face, trunkal obesity, HTN
ii. Prolonged exposure to high levels of cortisol
1. Zona fasciculate
iii. Pituitary tumor produces large amounts of ACTH
1. Adrenal glands  more cortisol
iv. Other causes  adenoma or carcinoma of the cortex
u. Adrenal insufficiency (addison’s disease)
i. Adrenal glands produces too little cortisol and maybe
Too much aldosterone
1. Increased pigmentation
2. Muscular weakness
3. Hypotension
ii. Can be caused by TB or bilateral atrophy of adrenal cortices
1. Autoimmune in 80% cases
iii. Diagnosed through blood tests and imaging
iv. Treated through hormone replacement (hydrocortisone)
v. Disturbances of adrenal medulla
i. Pheochromocytoma  rare, usually benign tumor of adrenal medulla
ii. Too much epinephrine/norepinephrine
iii. Irritability, pallor, palpitations, tachycardia, HTN and BP spikes, HA, sweating, weight loss
2. Vessels and lymphatics of the posterior abdominal viscera and wall
a. Abdominal aorta
i. Most arteries supplying posterior abdominal wall come from abdominal aorta
ii. Begins at aortic hiatus (T12) and ends at L4  divides into right and left common iliac arteries
1. Common iliac arteries run inferolaterally, following the medial border of the psoas
muscles to the pelvic brim
2. Each divided into internal and external iliac arteries
b. Branches
i. Branches of abdominal aorta course 3 vascular planes
ii. Will be visceral or parietal, Paired or unpaired
iii. Visceral branches
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1. Paired
a. Middle suprarenal artery, renal artery, and gonadal artery (testicular/ovarian)
2. Unpaired
a. Celiac trunk, SMA, IMA
iv. Parietal
1. Paired
a. Inferior phrenic artery
b. Lumbar artery (many segmental)
2. Unpaired
a. Median sacral artery
c. Inferior Vena Cava
i. Begins anterior to L5 by union of common iliac veins
ii. Ascends along R. psoas major to right of aorta
iii. Leaves abdomen by passing through the caval
Opening (hiatus) in the diaphragm and enters the thorax at T8
iv. Tributaries
1. Paired visceral
a. Renal veins
b. Right gonadal vein
i. Left into L renal vein
c. Right suprarenal vein
i. Left into L renal vein
2. Paired parietal
a. Inferior phrenic veins
b. Lumbar veins (L3 and L4)
c. Common iliac vv
3. Hepatic veins
a. Right, middle, left
v. Veins of posterior abdominal wall are all tributaries of the IVC except left testicular or ovarian
vein; left suprarenal v enters the left renal vein instead of entering IVC
vi. IVC returns poorly oxygenated blood from lower limbs, most of back, abdominal walls, and
abdominopelvic viscera
vii. Blood from abdominal viscera passes through portal venous system and liver before entering
the IVC via hepatic veins
d. Lymphatic vessels and lymph nodes
i. Parallels arterial supply
ii. External and internal iliac lymph nodes
 common iliac lymph nodes 
R and L lumbar lymph nodes  lumbar
lymph trunk
iii. Cisterna chili  L1/L2, between aorta
and R crus
iv. Lymph from alimentary tract, liver, spleen,
and pancreas passes to the preaortic lymph nodes
(celiac, superior, and inferior mesenteric nodes)
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Lecture 13 – Urinary System
1. Kidneys
a. Retroperitoneal
b. T12-L3 (right kidney is slightly inferior)
i. Due to liver; prevents it from
rising
c. Rests primarily on quadratus luborum m
d. Supported by 4 layers of tissue
(superficial  deep)
i. Pararenal fat
ii. Renal fascia
iii. Perirenal fat
iv. Renal fibrous capsule
e. Relationship of kidneys
f. External anatomy
i. Hilum
1. Renal artery
2. Renal vein
3. Ureter
4. Nerves
5. Lymphatics
g. Internal anatomy (picture to right)
h. Cortex and medulla
i. Nephron is functional unit of
The kidney
ii. Bowman’s capsule and some of the
Collecting ducts are located in
The cortex
iii. The ducts of the nephron and the majority of the collecting ducts are located in the medulla
i. Vasculature
i. Arteries
1. Renal a  divisions (ant/pos) aa  segmental aa (superior, inferior, anterior superior,
anterior inferior, posterior )  interlobar aa  arcuate aa  cortical radiate aa
ii. Veins
1. Glomerulus  renal portal system  veins (same as arteries)  IVC
j. Regions supplied by segmental arteries
i. Each section/segment of the kidney is supplied by a segmental artery
ii. Segmental arteries are end arteries; they don’t anastomose
k. Autonomic innervation
i. Innervated by the renal plexus (symp. and parasymp)
ii. Fibers travel along the renal aa
iii. SNS (PrG fibers from greatersplanchnic n) synapse in the
Celiac ganglion
iv. PoG fibers contribute to renal plexus, causes vasoconstriction,
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Reducing renal blood flow
v. Function of the parasympathetic nervous system (PrG fibers within vagus n) is minimal; it may
cause vasodilation
renal
plexus
l.
Sensory innervation
i. Sensory fibers travel within the vagus nerve and splanchnic nn (lesser and least) to the brain and
spinal cord levels T10-L1
ii. Referred pain, maybe due to a kidney disorder, is often perceived in the corresponding
dermatomes
m. Lymphatics
i. Renal lymphatics follow renal vv and drain into lumbar trunks and nodes, then to cisterna chyli
thoracic duct
n. *Clinical connection
i. Renal cancer
1. Renal cell carcinoma is most common type of kidney cancer (80%)
2. Originates in the lining of the proximal convoluted tubule
3. Often asymptomatic until it is at an advanced stage
4. Common symptoms  hematuria, pain between hip and ribs, abdominal mass
5. Lifestyle is greatest risk factor; 50% of cases are due to smoking, obesity, and HTN
6. Survival rate greatly depends on stage at which the cancer is discovered
ii. Polycystic kidney disease
1. Genetic disorder, most common form being autosomal dominant PKD (ADPKD)
2. A more common life-threatening genetic disorder in the world
3. Characterized by large fluid filled cysts that enlarge the kidneys
4. 1:500 births
iii. Kidney stones
1. Form when urine contains more crystal forming substances than the urine can dilute;
calcium, oxalate, and uric acid
2. Most common form composed of calcium
3. Urine may lack substances that keep crystals from sticking together
4. Risk factors include family history, adult male, diet (high in protein, salt, sugar),
dehydration, and obesity
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o. Urine flow in kidney
i. Nephron  collecting tubule  renal papilla  minor calyx  major calyx  renal pelvis 
ureter
ii. Urine flow occurs via peristalsis of smooth muscle in walls of calyces
2. Ureters
a. Retroperitoneal
b. Tubes of smooth muscles
c. 25-30 cm in length
d. “water under the bridge”
e. Constrictions
i. Diameter of the ureter is not uniform throughout its length; there are short sections where
diameter is reduced, creating a site where obstruction can occur
ii. 3 sites where the ureters are constricted
1. Ureteropelvic junction
2. Pelvic brim
3. Within bladder wall (ureteric ostia)
f. Vasculature
i. Ureteric aa  small and delicate
1. Derived from renal aa and vesical aa (via internal iliac artery, men) and uterine a (via
internal ilia artery, women)
2. Braches can arise from gonadal aa, abdominal aorta, and common iliac aa
3. Weak anastomosis forms between these branches
ii. Ureteric vv drain into veins traveling with the arteries
g. Innervation
i. Ureters have intrinsic pacemaker cells that control peristalsis
ii. Ureters receive autonomic and sensory fibers
iii. Autonomic fibers derive from renal, and superior hypogastric, and inferior hypogastric
plexuses
iv. Most parasympathetic fibers that contribute to these plexuses derive from S2-S4 pelvic
splanchnics
v. Mucosal irritation and luminal distension stimulate nociceptors with afferent fibers that travel
with sympathetic nerves and confer visceral-type referred pain
3. Urinary Bladder
a. Thick-walled, muscular, distensible, hollow organ that serves as a storage site of urine
b. Position and shape depend on volume of urine inside and the content of viscera around it
c. Retropubic space  small space that separates
the bladder from the pubic bone anteriorly
d. Peritoneum lies on superior surface only
e. Ligaments
i. Lateral ligaments of the bladder
ii. Puboprostatic ligament (male)
iii. Pubovesical ligament (women)
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f.
Regions of the bladder (picture)
g. Bladder layers
i. Detrusor muscle  comprised of smooth muscle
ii. When bladder is empty, rugae form
iii. Detrusor remains relaxed to allow bladder to store urine
iv. Detrusor contracts during urination
h. Orifices
i. Ureteric orifices, Internal urethral orifice
ii. Trigone  smooth triangular region delineated by ureteric orifices and internal urethral orifice
i. Vasculature
i. Supplied by branches of internal iliac aa  superior vesical aa, and inferior vesical aa
ii. Veins travel with the arteries and return blood to internal iliac veins
j. Autonomic innervation
i. Sympathetics
1. PrG cell bodies located in lateral horn of spinal cord T12-L2; fibers travel through
splanchnic nerves; synapse in inferior mesenteric ganglion
2. PoG fibers descend and contribute to inferior hypogastric plexus traveling to bladder
3. Sympathetic nervous system constricts the internal urethral sphincter
ii. Parasympathetics
1. PrG cell bodies are located in lateral horn of spinal cord segments S2-S4
2. PoG fibers travel through pelvic splanchnic nerves, contributing to inferior hypogastric
plexus
a. Synapse on PoG cell bodies in wall of bladder
3. Parasympathetic nervous system contracts the detrusor muscle and relaxes the
internal urethral sphincter
k. Sensory innervation
i. Visceral afferents from pelvic organs travel through sympathetic nerves or parasympathetic
nerves, depending on part of the organ or if it is above or below the pelvic pain line
1. Pelvic pain line corresponds to inferior edge of peritoneum
ii. Part of organ above the pelvic pain line if it is in contact with peritoneum
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iii. Visceral afferents of parts of the organ above pelvic pain line return via sympathetic nerves
iv. Afferents below pelvic pain line return via parasympathetic nerves
l.
Lymphatics
i. Lymph from superior part of the bladder passes to the external iliac lymph nodes
ii. Lymph from inferior part of the bladder passes to internal iliac lymph nodes
iii. Lymph flows to the cisterna chyli from both sets of nodes
m. Control of urination
i. When empty, detrusor muscle
is relaxed by sympathetic
division (hypogastric n) and
internal urethral
sphincter is contracted
ii. When full, detrusor muscle
contracts, internal urethral
sphincter relaxes (parasympathetic
divison via pelvic splanchnics)
iii. External urethral sphincter
Under voluntary control;
innervated by pudendal n
(from axons emerging
from S2-S4 ventral rami)
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Lecture 14 – Posterior Abdominal Wall
1. Thoracoabdominal Diaphragm
a. Mainly composed of …
i. 5 lumbar vertebrae and assoc. IV discs
ii. Post. Abdominal wall muscles
iii. Diaphragm, which contributes to superior part
of wall
iv. Fascia, including thoracolumbar fascia
v. Fat, nerves, vessels (aorta, IVC), lymph nodes
b. Between thoracic and abdominal cavities
i. Thin, voluntary muscle
ii. Dome shaped
c. Origin
i. Sternal, costal, costal vertebral
d. Insertion
i. Central tendon
e. Innervation
i. Phrenic nerves  motor (C3-5)
ii. Intercostals (T6-T11, subcostal)  sensory to periphery
f. Central tendon
i. vena caval hiatus: T8
g. Right crus
i. Originates off L1-L3 bodies, IV discs
ii. Larger than left crus
iii. Primarily forms esophageal hiatus: T10
h. Left crus
i. Origin  L1-L2/3, IV discs
i. Aortic hiatus: T12
i. Left and right crus form this together
ii. Azygos vv, thoracic duct also through here
j. Arcuate ligaments
i. Median  unpaired, between crura, over aortic hiatus
ii. Medial  over psoas major
iii. Lateral  over quadratus lumborum
2. Muscles of posterior abdominal wall
a. Psoas major
i. “tenderloin”
ii. Lumbar plexus of nerves embedded in posterior part of psoas; anterior to lumbar transverse
processes
iii. Origin
1. Transverse processes of L1-L5
2. Vertebral bodies and IV discs of T12-L5
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iv. Insertion
1. Lesser trochanter
v. Innervation
1. Ventral rami of L1-L3
vi. Main action
1. Acts inferiorly with iliacus; flexes thigh
2. Superiorly, it flexes vertebral column laterally
3. Used to balance the trunk (lateral flex trunk)
4. Acts inferiorly with iliacus to flex trunk when sitting
b. Psoas minor
i. Will see sitting on top of psoas major, with long tendon
ii. Origin
1. Vertebral bodies T12-L1
iii. Insertion
1. Iliopubic eminence
iv. Action
1. Weak flexor of trunk
v. Innervation
1. Ventral ramus L1
c. Iliacus
i. Large triangular muscle lying along lateral aspect of inferior part of psoas major
ii. Psoas and iliacus form iliopsoas, the chief flexor of thigh
iii. Stabilizer of the hip joint
iv. Psoas and iliacus share in thigh flexion, but only psoas can produce movement of lumbar
vertebral column;
v. Origin
1. Superior 2/3 iliac fossa
2. Ala of sacrum
3. Anterior sacroiliac ligaments
vi. Insertion
1. Lesser trochanter, psoas major tendon
vii. Innervation
1. Femoral nerve (L2-L4)
viii. Main action
1. Flexes thigh
2. Stabilizes hip joint
d. Quadratus lumborum
i. Forms thick muscular sheet in posterior abdominal wall; posterior to kidney
ii. Branches of lumbar plexus fun inferiorly along anterior surface of this muscle
iii. Muscle fibers run say direction as psoas major; it will be just lateral to that muscle
iv. Posterior to kidney
v. Origin
1. Medial half of inferior border of 12th ribs
2. Tips of lumbar transverse processes (L1-L4)
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vi. Insertion
1. Iliolumbar ligament and internal lip of iliac crest
vii. Innervation
1. Ventral rami of subcostal n (T12) and L1-L4
viii. Main action
1. Extends and laterally flexes vertebral column
2. Fixes 12th rib during inspiration
3. Fascia of Posterior abdominal wall (picture top right)
a. Psoas fascia covers psoas major muscle
i. Attached medially to lumbar vertebrae and pelvic brim
ii. Psoas fascia thickened superiorly to form the medial arcuate ligament
iii. Inferior to iliac crest, the psoas fascia is continuous with the part of iliac fascia, covering the
iliacus
b. Psoas fascia fuses laterally with the thoracolumbar fascias
c. Transversalis fascia anterior to transversus abdominis
4. Nerves of Posterior abdominal wall
a. Subcostal nerves (ventral rami of T12)
i. Technically not part of lumbar plexus
ii. Arise in thorax, pass posterior to lateral arcuate ligaments into abdomen, and run
inferolaterally on anterior surface of quadratus lumburum; see it passing under 12th rib
iii. Pass through transversus abdominus and internal oblique muscles to supply external oblique
and skin of anterolateral abdominal wall
b. Lumbar plexus of nerves
i. Formed anterior to lumbar transverse processes, within proximal attachment of psoas major
ii. Ventral rami of L1-L4 nerves
iii. Branches of lumbar plexus
1. Ilioinguinal and iliohypogastric nerves (L1)
a. Supplies abdominal muscles and skin of inguinal and pubic regions
2. Genitofemoral nerve (L1-L2)
a. Pierces psoas major and runs inferiorly on its anterior surface, deep to psoas
fascia
b. Divides lateral to common and external iliac arteries into femoral and genital
branches
3. Lateral femoral cutaneous nerve of thick (L2-L3)
a. Supplies skin on anterolateral surface of the thigh
4. Femoral nerve and obturator nerve (L2-L4)
a. (femoral) Emerges from lateral border of psoas major, innervates iliacus and
passes deep to inguinal ligament tract to anterior thigh, supplying flexors of
hip and extensors of the knee
b. (obturator) emerges from medial border of psoas major and passes into lesser
pelvis, passing through obturator foramen to medial thigh, supplying adductor
muscles
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i. *obturator nerve is vulnerable to injury during surgery; injury causes
painful spasms of adductor muscles of the thigh, also sensory deficits
of medial thigh
5. Accessory obturator nerve (L3-L4)
6. Lumbosacral trunk (L4-L5)
a. Passes over ala of sacrum and descends into elvis to participate in formation of
sacral plexus with ventral rami of S1-S4
c. Sacral plexus
i. Located on posterolateral wall of lesser pelvis
1. Sciatic and pudendal nerves  lie external to parietal pelvic fascia
ii. Most branches of sacral plexus leave pelvis through greater sciatic foramen
iii. During childbirth, fetal head may compress nerves of mother’s sacral plexus, producing lower
limb pain
iv. Sciatic nerve
1. Largest nerve in body
2. Formed as large ventral rami of L4-S3 converge on anterior surface of the piriformis
3. Passes through greater sciatic foramen
4. Supplies posterior thigh, entire leg and foot
5. Muscular branches to flexors of knee in thigh and all musucles in leg and foot
6. Two major division  tibial nerve and common fibular nerve bound in tissue sheath;
usually separate in distal thigh
v. Pudendal nerve
1. Main nerve of perineum, chief nerve of external genitalia
2. Leaves pelvis through greater sciatic foramen between piriformis and coccygeus muscles
3. S2-S4 origin
4. Distribution  structures of perineum; sensory to genitalia; muscular branches to
perineal muscles, external urethral sphincter, and external anal sphincter
vi. Superior and inferior gluteal nerves
1. Superior gluteal nerve  leaves pelvis through greater sciatic foramen
a. Origin  L4-S1
b. Distribution  gludeus medius and gluteus minimus muscles
2. Inferior gluteal nerve  leaves through greater sciatic foramen, superficial to sciatic
nerve, accompanying inferior gluteal artery
a. Origin  L5-S1, S2
b. Distribution  gluteus maximus
Nerve
Sciatic
Origin
L4, L5, S1,
S2, S3
Distribution
Articular branches to hip joint and muscular branches to flexors of knee in
thigh and all muscles in leg and foot
Superior gluteal
L4, L5, S1
Nerve to quadratus femoris
(and inferior gemellus)
L4, L5, S1
Gluteus medius and gluteus minimus muscles
Inferior gluteal
Gluteus maximus
L5, S1, S2
Quadratus femoris and inferior gemellus muscles
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Nerve to obturator internus
(and superior gemellus)
L5, S1, S2
Obturator internus and superior gemellus muscles
Nerve to piriformis
S1, S2
Posterior cutaneous nerve
of thigh
S2, S3
Piriformis muscle
Cutaneous branches to buttock and uppermost medial and posterior
surfaces of thigh
Perforating cutaneous
S2, S3
Pudendal
S2, S3, S4
Cutaneous branches to medial part of buttock
Structures in perineum: sensory to genitalia, muscular branches to perineal
muscles, external urethral sphincter, and external anal sphincter
Pelvic splanchnic
Nerves to levator ani and
coccygeus
S2, S3, S4
Pelvic viscera via inferior hypogastric and pelvic plexuses
S3, S4
Levator ani and coccygeus muscles
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5. Effects of lesions on nerves
Nerve
Levels
Motor Effects
Sensory Effects
Hip flexion, knee extension. Innervated
muscles: Iliopsoas, pectineus, sartorius, Area covered by anterior cutaneous branch and the
Femoral
L2-L4 quadriceps femoris
Obturator
L2-L4 Thigh adduction
Cutaneous branch: sensation to medial thigh
Articular branches to hip joint, muscular
branches to flexors of knee in thigh, and
L4-S3 all muscles in leg and foot
Sciatic
saphenous n.
Common
fibular
L4-S2 Ankle dorsiflexion (extension)
Lateral calf
Superficial
fibular
L4-S2 Foot eversion
Top of foot and middle toes. Sensory branches:
medial dorsal & intermediate dorsal cutaneous n.n.
Deep
fibular
Area between big and 2nd toes. Lateral cutaneous n.
of big toe, medial cutaneous nerve of 2nd toe
L4-S2 Toe extension
Medial and lateral plantar nerves;
Adductors and flexors – ankle plantar
Tibial
Superior
gluteal
L4-S3 flexors
Back of calf, bottom of foot
Gluteus medius, gluteus minimus,
L4-S1 tensor fasciae latae
Inferior
gluteal
L5-S2 Gluteus maximus
6. Testing nerve integrity
a. Femoral  assess hip flexion, knee/leg extension
b. Obturator  assess thigh adduction
c. Sciatic  assess knee flexion
i. Common fibular: assess ankle dorsiflexion
ii. Tibial: assess ankle plantar flexion
d. Inferior gluteal  high/thigh extension, lateral rotation
i. Injury to this nerve leads to gluteus maximus lurch
ii. When gluteus maximus is injured, trunk extends (lean back) on heel-strike on weakened side
iii. Compensates for weakness of hip extension
e. Superior gluteal nerve
i. Abducts/stabilizes thigh; keeps pelvis level during gait
ii. When there’s a lesion of superior gluteal nerve, patient should be asked to stand on one leg
iii. The pelvis on the unsupported side descends indicating that the gluteus medius and minimus
on the supported side are weak or non-functional
1. Sign referred to as positive trendelenburg test
2. Sign could also be caused by fracture of the greater trochanter and dislocation of the hip
joint
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Lecture 15 – Development of the Urinary System
1. Kidney Development
a. We form 3 sets of kidneys and only one of them becomes functional
b. The pronephros is the most immature form of the kidney; represents the first stage of kidney
development in most species, but became only functional in ancient fush (hagfish) or during larval stage
of amphibians
c. Mesonephros represents second stage of kidney development in most animal species; have to expel
these because they occupy the space where intestines form
d. Metanephros is last stage of kidney development after degeneration of pronephros and mesenephros in
reptiles, birds and mammals, and persists as definitive adult kidney
e. Pronephros
i. Kidney is derived from intermediate mesoderm
ii. Cells of the IM begin to cluster in cervical region at 4th week
iii. The clusters (nephrotomes) and this entire vestigial kidney is the pronephros
iv. Pronephros is non-functional and degenerates by the end of the 4th week
f. Mesonephros
i. Begins to form later in the 4th week from thoracic and upper lumber intermediate mesoderm
(nephrotomes)
ii. Many units from which are similar to mature nephrons, but all of these will degenerate
iii. Mesonephros produces urine from 6th-10th weeks
iv. Wolffian (mesonephric) duct forms in males in response to testosterone and connects the
mesonephros to the cloaca; this duct develops into some male reproductive structures (vas
deferens) and the trigone of the bladder in males and females
v. Remnants of this duct remain in females sometimes
g. Metanephros
i. Permanent kidney
ii. Begins to form during 5th week
iii. Close to entrance of mesonephric duct into the cloaca, the ureteric bud sprouts and penetrates
the metanephric blastema (intermediate mesoderm in sacral region that differentiates into
nephrons)
iv. The ureteric bud gives rise to…
1. Ureter
2. Renal pelvis
3. Major calyces
4. Minor calyces
5. Collecting tubules (1-3 million!)
v. SO…basically the ureteric bud unites with
the metanephric blastema to form the developing
kidney in 6th week; The ureter develops a separate
opening into the bladder and the kidney
ascends in weeks 6-7
2. Nephron formation
a. Metanephric blastema gives rise to nephric vesicles which differentiate into nephrons
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b. Nephrons continue to form until birth
c. Derivatives  metanephric blastema (forms the cortex) , ureteric bud (forms medulla)
3. Ascension of the kidneys
a. Growth of the embryo in length causes kidneys to move up; so basically, the kidneys don’t ascend due to
active migration…they move down because of the differing growths of sacral and lumbar regions (this
leads to lengthened caudal end of the embryonic body)
b. Rather than drag their blood supply with them as they move, the kidneys send out new and more
superior branches, then then induces the regression of the more caudal branches
c. *Clinical connection
i. Pelvic kidney
1. Kidney fails to ascend
2. Person might go through entire life not
Knowing they have this condition
ii. Horseshoe kidney
1. Developing kidneys fuse ventrally into a large
Horseshoe-shaped kidney
2. Ascent is impeded by IMA
3. Asymptomatic usually; person may feel
Nausea or discomfort; develop kidney stones
And UTIs
iii. Renal agenesis
1. Caused by ureteric bud failing to penetrate metanephric blastema, or the ureteric bud
fails to form
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4. Urinary Bladder Development
a. During weeks 4-7, cloaca divides into urogenital sinus and anal canal via urorectal septation
b. Most of the urogenital sinus becomes urinary bladder
c. Urinary bladder communicates with mother via allantois (called urachus when it closes)
d. Caudal portions of mesonephric ducts are incorporated into the urinary bladder
e. Ureters shift cranially separating from mesonephric ducts
f. Mesonephric ducts become vas deferens
g. *Clinical connection
i. Extrosophy of the bladder
1. Urinary bladder is opened and on surface of anterior body wall
2. Probably due to incomplete closure during lateral body folding
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Lecture 17 – Radiology of the urinary system
1. Plain films of abdomen
a. Rarely used for kidney and urinary systems
b. Used for radiopaque stones (calcium, struvite, cysteine)
c. Low sensitivity and specificity in patients with sx but no hx of stones
d. There is minimal radiation compared to CT
e. In plain film, can see points of narrowing, where stones may be noted
2. Renal Ultrasound
a. Evaluation of cystic kidney disease
b. Diagnosis of hydronephrosis
c. Measure kidney size and echogenicity as part of evaluation of chronic kidney disease
d. Detection of renal artery occlusive disease via Doppler images
e. No exposure to radiation or contrast, so good for pregnant people and good for kids
f. Limitations
i. Interpretation operator dependent
ii. Harder in overweight people
g. Can see Doppler flow studies; can evaluate patients for vascular occlusive disease this way
i. Showing you blood flow
3. IV pyelography
a. Indications
i. Delineation of gross anatomy of renal and urinary tract
ii. Evaluation of medullary sponge kidney and papillary necrosis
iii. Because contrast gets into kidney, you can see it very well
b. Limitations
i. Radiation, contrast dye allergies, can worsen impaired renal function (because dye will get into
glomerulus and may not filter right)
c. Use of contrast is helpful to see function and anatomy of renal system
4. Voiding cystourethrogram
a. Used to evaluate vesicoureteral reflux most common from posterior ureteral valves (the insertion of
ureter into bladder issue)
b. Uses fluoroscopy or multiphase imaging; does involve radiation
c. Usually done in conjunction with ultrasound; usually done in kids?
d. Pictures showing different grades of reflux
e. Grade 1. Just a little trickle backwards
f. Grade 2. Goes up into kidney but no dilatation
g. Grade 3. Start seeing dilatation, and expansion; lower system starting to dilate due to backup
h. Grade 4. Dilation of whole system, including ureter
i. Grade 5. Almost get blackout of kidney, lose cauliflower look
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5. Computed tomography
a. Standard for diagnosing nephrolithiasis (kidney stone)
b. Evaluating kidney masses and staging renal tumors
c. Evaluating polycystic kidney disease
d. Can be done multiphase to follow contrast through urinary system
e. Should have some idea of what diagnosis is before doing a CT
f. Limitations
i. Radiation, contrast (can be done without contrast as for renal stone evaluation)
g. Should be able to tell which is right from left and that left disappears a little sooner (because right is
lower due to kidney…look for the liver!)
6. MRI
a. Assessment of kidney anatomy; noninvasive assessment for kidney function and estimation of GFR
b. Assessment of congenital anomalies of kidney, bladder, and urinary tract
c. Limitations
i. Image quality with undistended urinary system
ii. Not sensitive for calculi
iii. Patient cooperation needed (longer imaging required)
7. Radionuclide scanning
a. Evaluate renal perfusion (thrombosis, stenosis)
b. Evaluate for renal scarring
c. Vesicoureteral reflux in children  more sensitive than voiding cystourethrogram but more complex of
a study (VCUG may be negative, but this could be a better detection)
d. Technique
i. Inject 99mTc DMSA
ii. Radionuclear scanning done but it takes time
e. Areas with less DMSA uptake consistent with scarring in a patient with vesicoureteral reflux
8. Renal angiography
a. Imaging of choice for direct visualization of renal vasculature
b. Evaluation for renal artery stenosis, renal vein thrombosis; if patient comes in and they have
uncontrolled HTN even if on medications
c. Limitations
i. Requires arterial access, contrast
ii. Usually done through common iliac
d. Can see narrowing of renal arteries