where is the psoas major muscle
alongside the lumbar vertebra (L1-L4, usually not L5), originates in transverse processes intervertebral discs and bodies of associated vertebra
where is the psoas minor muscle
in less than 50% of pop; lies on anterior surface of psoas major and inserts into the iliopubic eminence
what two muscles join to form the iliopsoas muscle and where do they join?
psoas major muscle and iliacus muscle; join under the inguinal ligament, in front of the hip joint
wehre does iliopsoas muscle attach?
to the lesser trochanter of the femur
where is the quadratus lumborum?
just posterolateral or psoas major; occupies medial half of gap between 12th rib, iliac crest and tips of the lumbar transverse processes
where does the iliolumbar ligament attach and run?
attaches to transverse process of lumbar (not sacral) vertebra to the iliac crest and runs along superior margin of iliac crest corresponding to the attachment of hte quadrates lumborum; usually only located on L4 and L5
what is the purpost of iliolumbar ligament?
add stability to attachment of bony pelvis to spine and is most notable in laterally bendign torso
what are the attachments of the diaphragm?
posterior: fascia of psoas major and quadratus lumborum, and posterior wall via the right and left crurae (this leaves a gap called aortic hiatus)
where does left crus of diaphragm attach?
L1-L2 or L3
where does right crus of diaphragm attach?
L1-L3 or L4
right crus fibers wrap around waht structure to form what?
wraps around esophagus forming the esophageal hiatus
three fascial-like thickenings of the diaphragmatic attachments to posterior abdominal wall
the arcuate ligaments: mediaN arcuate ligament (hiatus for aorta and thoracic duct), mediaL arcuate ligament (@L1 and passes over psoas major muscle), lateral arcuate ligament (arches over quadratus lumborum and runs from transverse process of L1 to the 12th rib.
area above lateral arcuate line
lumbocostal trigone (or Bochdalek's triangle)
aorta bifurcates at what level?
lower L4 or upper L5
four paired "glandular" branches of the aorta?
inferior phrenic, middle suprerenal, renal, gonadal arteries (inferior phrenic and middle suprarenal arteries supply superior and middle aspects of the suprarenal glands respectively)
three unpairs visceral branches of aorta
celiac trunk, superior and inferior mesenteric arteries
four paired dorsal branches of aorta?
the lumbar arteries (supply L1-L4)
Where do L1-L3 lumbar arteries pass?
pass posterior to both psoas major and quadratus lumborum ms
Where does the L4 Lumbar artery run?
parallels the iliolumbar ligamen, passes posterior to the psoas major but anterior to the quadratus lumborum and goes along superior edge of the iliac crest
Where do the L5 lumbar arteries originate?
they are lateral segmental branches off the middle sacral artery (which is hte continuation of the aorta after aortic bifurcation)
where does iliolumbar artery run?
runs parallel to L4 lumbar artery but along inferior edge of iliac crest to eventually anastomose with the deep circumflex iliac artery
at what level is the IVC formed?
~L5 by union of left and right common iliac veins which occurs just posterior to the right common iliac artery
where does the middle sacral vein drain?
into the left common iliac vein
where do hepatic veins enter the IVC and what do they drain?
enter it anteriorly just below the diaphragm and drain teh digestive tract via the portal system
veins on left drain into what structure before going into the IVC?
the left renal vein
what drains into the left renal vein?
left kidney, left gonadal, left suprarenal, let inferior phrenic veins
how do the lumbar veins drain?
many of the lumbar veins anastomose to form the ascending lumbar vein (which lies deep b/n psoas muscle and vertebral bodies and runs parallel to the IVC)
the dilated distal end of the thoracic duct located b/n the aorta and the right crus of the diaphragm at about L1
what forms the cisterna chyli?
union of common lumbar lymph trunk and intesetinal lymph trunk
lumbar lymph nodes drain what?
posterior body wall, kidneys, suprarenals, ureters, left colon and gonads
external and common iliac nodes drain what?
the inguinal nodes (lower limb, perineum and butt) and the internal iliac nodes (pelvic brin and lowest rectum)
all rami below what vertebral level are grey?
lumbar splanchnic nerves contribute to what?
contribute to aortic plexus and are generally considered to be preganglionic myelinated fibers
where does the lumbar plexus originate?
from the ventral rami of L1-L4 and a portion of L5
the lumbar plexus is split into two divisions
anterior and posterior
what are the four named nerves of the anterior division and where do they originate?
iliohypogastric (L1), ilioinguinal (L1), genitofemoral (L1 and L2) and obturator (L2-L4)
where is the genitofemoral nerve?
anterior to the iliohypogastric and ilioinguinal and lies on the surface of the psoas major m. innervates cremaster muscle
where does the obturator nerve lie?
runs through obturator foramen and canal, distributed to medial thigh muscles and some overlying skin
what are the posterior division nerves of the femoral plexus called and where do they originate?
lateral femoral cutaneous nerve (L2, L3), femoral nerve (L2-L4)
what does the lateral femoral cutaneous nerve innervate?
lateral aspect of the skin of the thigh
where does the femoral nerve run and what does it supply?
passes under inguinal ligament with the iliopsoas muscle to innervae muscles and skin of anterior thigh
the combination of descending rami of L4 and ventral rami of L5 combine to form what what does it do?
the lumbosacral trunk; participates in sacral plexus distribution; this connection gives it hte name lumbosacral plexus
where is the lumbar plexus?
in the psoas major muscle
where does the femoral nerve run?
in the groove between psoas major and iliacus muscle
where does the obturator nerve lie?
between the psoas muscle (lateral) and teh lumbar vertebral bodies (medial) and posterior to the internal iliac vessels
name the border of the pelvis
pelvic girdle (lesser and greater pelvis)
where is the pelvic cavity
the space between the pelvic inlet and the pelvic diaphragm and is continuous with the abdominal cavity
name the parts of the pelvic brim
pubic crest, pecten pubis, arcuate line of the ilium, and sacral promontory
what composes the linea terminalis?
the pectin pubis and the arcuate line of the ilium
what forms the floor of the pelvis?
the pelvic diaphragm
what muscles make up the pelvic diaphragm?
levator ani muscle (anterior) and coccygeus muscle (posterior)
from the sacral promontory to inferior margin of pubic symphysis
transverse (or interspinous) diameter
diameter measured just behind ischial spines
from sacroiliac joint to iliopubic eminence
superior pelvic aperture
sloped plane; plane of pelvic inlet; posterior edge is S1 level (sacral promontory), anterior edge (pubis, which is about same level as coccyx)
do the anterior superior iliac spine and the pubic symphysis lie in approximately same coronal plane?
the functions of the pelvis
transmits weight from torso to the lower extremities; houses and supports teh organs in perineum and pelvic area; provides skeletal framework for muscle attachment
the three bones in pelvic region and their locations
sacrum (posterior), hip bones (aka coxal bones), coccyx
the three parts of the coxal bone
ilium (largest + most superior)
ischium (posterior and inferior)
pubis (anterior inferior part)
ilium has two parts
body and a wing (aka Ala)
ischium has two parts
body and a ramus
pubis has two parts
superior ramus (cncts with the ischium and ilium forming acetabulum)
inferior ramus (with ischial ramus forms ischiopubic ramus)
the ligaments that attaches the sacrum to the ischium
sacrotuberous ligament (sacrum to ischial tuberosity)
sacrospinous ligament (sacrum to ischial spine)
the sacrospinous ligament splits what foramen into what subforamina?
the sciatic foramen into greater and lesser sciatic foramen
most blood vessels and nerves leave the pelvis through what foramen?
greater sciatic foramen
the pudendal nerve and teh internal pudendal artery leave the pelvis how and enter teh perineum how?
leave via greater foramen, hook around ischial spine and sacrospinous ligament and enter perineum through lesser sciatic foramen
two muscles of lower limb that help form pelvic wall
obturator internus and piriformis muscle
where is the obturator internus?
largely covers the obturator foramen and has its tendon passing through the lesser sciatic foramen; tendon attaches to femur
wehre is the piriformis muscle?
arises from anterior aspect of sacrum, then passes through and largely fills the greater sciatic foramen, tendon attaches to femur
what are the coccygeus muscle attachements?
ischial spines to the sides of the sacrum and coccyx
levator ani has attachments where?
pubis anteriorly and along the fascia which lies on the obturator internus
levator ani has three subdivisions
pubococcygeus muscle (attached to pubis), iliococcygeus (arises from tendinous arch on obturator fascia), puborectalis muscle (arises from pubis anteriorly and joins with anal canal) pl 340
desc. the perineum
a diamond-shaped compartment that is bounded by pubic symphysis anteriorly, ischiopubic rami anterolaterally, ischial tuberosities laterally, sacrotuberous ligaments posterolaterally and inferior part of sacrum and coccyx posteriorly
the urogenital triangle is divided by what into what?
divided by perineal membrane into a superficial perineal pouch inferiorly and a deep perineal pouch superiorly, two spaces on each side of the membrane
what does the perineal membrane cover?
the anterior part of the pelvic outlet, extending from the inferior portion of the pubic symphysis to the ischial tuberosities
what levels does the pudendal nerve come from and what route does it take to supplying its ends?
S2-S4, exits the pelvis via greater sciatic foramen and comes back around through lesser sciatic foramen to enter pudendal canal and innervate external genitalia and structures of superficial perineal pouch
what are the terminal branches of the pudendal nerve?
inferior rectal nerve (innerves external anal sphincter and muscles surrounding); perineal nerve (innerve muscles of perineum; has three branches); dorsal nerve (dorsal aspect of the penis; carries only sensory information)
what are the branches of the perineal nerve and what do they innervate
deep perineal nerve and superficial perineal nerve (which branches into posterior scrotal/labial nerves)
what branches does the internal pudendal artery give off?
inferior rectal artery, perineal artery, artery to the bulb, dorsal artery of the penis (clitoris), deep artery of the penis (clitoris) and urethral artery (males only)
how does the deep dorsal vein return to the pelvis?
it does not branch and goes in between transverse perineal ligament and the arcuate pubic ligament
where are the majority of the blood vessels and nerves of the perineum located?
in the urogenital triangle
how does the posterior femoral cutaneous nerve exit the pelvis, does it have any branches and if so what does it supply?
through the lacunar region; yes the perineal branch of the posterior femoral cutaneous nerve and it innervates large portion of perineum
where does the middle rectal artery originate?
usually from internal pudendal artery or inferior vesical artery
what branch of internal iliac supplies inferior aspect of bladder and also the prostate gland/
inferior vesical artery
in males, what are the four visceral branches of the internal iliac artery
superior vesicular artery, middle rectal artery, artery of the ductus deferns, inferior vesical artery
what does the superior vesical artery supply?
the superior aspect of the bladder
in females what are the branches off the internal iliac artery?
superior vesical, middle rectal, uterine (sides of uterus), vaginal artery (upper region of vagina)
the ureter passes how to the uterine artery?
ureter passes inferiorly and posteriorly to uterine artery ( water under the bridge)
where does the obturator artery run?
it parallels the obturator nerve and disappears into obturator canal
where does the internal pudendal artery run?
lies behind coccygeun muscle, passes through greater sciatic foramen, then goes into pudendal canal
wehre do the superior gluteal and inferior gluteal arteries run?
between large sacral nerves with the superior gluteal passing b/n the lumbosacral trunk and S1 and the inferior gluteal b/n S2 and S3
where does the lateral sacral pass and where does its branches go?
passes medially and inferiorly and gives off branches into the sacral foramina
where does the iliolumbar artery run?
goes from pelvis back into the abdomen and gives off two branches
waht are the branches of the iliolumbar artery?
iliac branch - goes to iliac fossa
lumbar branch - supplies structures lying close to the lumbar vertebrae (roughly parallels lumbosacral trunk)
what are the parietal branches of the internal iliac artery?
obturator, internal pudendal, superior and inferior gluteal, lateral sacral, and iliolumbar arteries
what is the anterior division of the internal iliac arteries in males?
umbilical, superior vescile, obturator, internal pudendal, middle rectal, inferior gluteal, inferior vesicle, artery to ductus deferens (from superior or inferior vesicle artery) and prostatic arterial branches (from inferior vesicle artery)
what is the anterior division of the internal iliac arteries in females?
umbilical, superior vescile, obturator, internal pudendal, middle rectal, inferior gluteal, uterine artery (from internal iliac or umbilical artery) and vaginal artery (from internal iliac or uterine artery)
what is the posterior division of the internal iliac arteries in both sexes?
superior gluteal, lateral sacral and iliolumbar arteries
what does the inferior rectal artery supply?
what does the perineal artery supply?
superficial transverse perineal muscle and posterior scrotum/labium majorus
what does the artery to penis/clitoris supply?
has two branches; trick question
what does the deep artery supply?
erectile tissue of penis or clitoris
waht does the dorsal artery supply?
nonerectile tissues of penis or clitoris (skin, fascia, prepuce and glans)