Pelvis Flashcards
Components of bony pelvis
right and left pelvic bones, fusion of ilium, ischium, pubis, sacrum, coccyx
midline of pelvic inlet
sacral promontory
boundaries of pelvic outlet
pubis, ischial rami, sacrotuberous ligament, coccyx
pelvic inlet in females
wider, more circular
pelvic inlet in males
narrow, heart-shaped
sacrum in females
short, straight
sacrum in males
long, prominent
coccyx in females
straighter
coccyx in males
curves ventrally
sciatic notch in females
wide
sciatic notch in males
narrow
subpubic angle in females
broad, rounded, 80-85 degrees
subpubic angle in males
deep, acute, 50-60 degrees
pelvic wall muscles
piriformis, obturator internus
components of pelvic floor
pelvic diaphragm, urogenital diaphragm
purpose of pelvic diaphragm
thin sheets of muscle through which the urethra, vagina, and rectum pass
muscles of pelvic diaphragm
levator ani, coccygeus
components of levator ani
iliococcygeus, pubococcygeus
purpose of levator ani
contract when abdominal pressure rises to support pelvic organs
purpose of pubococcygeus
maintain urinary and fecal continence
medial fibers of pubococcygeus
puborectalis
action of puborectalis
forms a sling around the rectum to relax and contract the anorectal angle to control defecation, aids in voluntary control of micturition
which muscles are injured during childbirth
pubococcygeus and puborectalis
muscle injury during childbirth can result in
urinary and fecal incontinence
coccygeus location
deep to the sacrospinous ligament
coccygeus action
pulls the coccyx forward after defecation
4 regions of uterus
fundus, body, isthmus, cervix
area in which the uterine tubes connect to the uterus
fundus
normal position of uterus
anteverted/anteflexed
flexion
angle between uterine body and isthmus
version
angle between cervical canal and vagina
normal anatomical variation in position of uterus
retroverted/retroflexed
parts of broad ligament
mesovarium, mesosalpinx, mesometrium
ovarian vessels travel through this to reach ovary from abdominal aorta
suspensory ligament of ovary
vesicouterine pouch location
between bladder and uterus
rectouterine pouch of douglas location
between uterus and rectum
most inferior part of peritoneal cavity when supine
rectouterine pouch of douglas
male equivalent of rectouterine pouch
rectovesical pouch
retropubic space
subperitoneal space between the bladder filled with fatty areolar tissue
pubovesical ligaments travel from
travel from pubic bones to bladder
transverse cervical ligaments aka
cardinal ligaments
transverse cervical ligaments travel from
uterus to lateral pelvic wall
uterosacral ligaments travel from
uterus to sacrum
what causes bladder prolapse
damage to pubovesical ligaments
what causes uterine prolapse
damage to transverse cervical ligaments
what causes damage to the fascial ligaments
chronic cough, heavy lifting, multiparity, birth trauma, obesity
components of male reproductive tract
prostate, seminal vesicles, vas deferens, testes
which elements of male reproductive tract are subperitoneal
prostate, seminal vesicle
which elements of male reproductive tract are closely associated with the urethra
prostate, seminal vesicle
the testes are attached to the seminal vesicle via the
vas deferens
course of the vas deferens
ascends from the scrotum in the spermatic cord, passes through the inguinal canal, and joins the ejaculatory ducts of the seminal vesicles
ejaculatory ducts location
embedded in the prostate
external spermatic fascia is derived from
external oblique aponeurosis
cremasteric fascia and muscle are derived from
internal oblique muscle
internal spermatic fascia is derived from
transversalis fascia
tunica vaginalis
pouch of peritoneum surrounding the testis with a visceral and parietal layer
descent of testis forms the
inguinal canal and spermatic cord
contents of spermatic cord
ilioinguinal nerve, genitofemoral nerve, testicular artery, pampiniform plexus, lymphatics, vas deferens
deep inguinal ring is an opening in the
transversalis fascia
superficial inguinal ring is an opening in the
aponeurosis of external oblique
the urethra runs through the (male)
corpus spongiosum
muscle that provides propulsive force during ejaculation
bulbospongiosus
branches of internal iliac artery common to males and females
iliolumbar, lateral sacral, superior gluteal, inferior gluteal, internal pudendal (inferior rectal branch), umbilical, obturator, middle rectal
female branches of internal iliac artery
uterine, vaginal
male branches of internal iliac artery
vas deferens branch off umbilical artery
ovarian artery is a branch of
the aorta
ovarian artery anastomoses with the
uterine artery
major blood supply to perineum and external genitalia
internal pudendal artery
branches of internal pudendal artery
inferior rectal, perineal, posterior labial/scrotal, artery of the bulb, dorsal/deep arteries of the clitoris/penis
uterine artery crosses ___ to distal ureters
anterior
ductus deferens crosses ____ to ureters
anterior
lymphatic drainage from areas supplied by internal iliac artery
internal iliac nodes to common iliac nodes to lateral aortic (lumbar) nodes
lymphatic drainage from perineum and lower limb
superficial and deep inguinal nodes to external iliac nodes to common iliac nodes to lateral aortic nodes
lymphatic drainage from areas supplied directly by aorta
lateral aortic nodes to cisterna chylli to thoracic duct
innervation of skin and skeletal muscles of pelvis
ventral rami of lumbosacral (L2-L4) and coccygeal spinal nerves to lumbosacral and coccygeal plexuses
parasympathetic innervation of smooth muscle and glands of pelvic viscera
pelvic splanchnics (S2-S4)
sympathetic innervation of smooth muscle and glands of pelvic viscera
thoracic, lumbar, and sacral splanchnics (T10-T12, L1-L2)
afferent fibers of lower vagina and perineum
travel via the pudendal nerves to S2-S4
preganglionic sympathetic neurons for pelvic viscera and smooth muscle
T10-T12 (lesser and least splanchnics), L1-L2 (lumbar splanchnics)
postganglionic sympathetic neurons for pelvic viscera and smooth muscle
hypogastric plexus via the pelvic ganglia
Afferent fibers of intraperitoneal pelvic viscera travel (eg uterine contractions)
with lesser/least splanchnics and lumbar splanchnics
preganglionic parasympathetic neurons for pelvic viscera and smooth muscle
pelvic splanchnics
afferent fibers of subperitoneal pelvic viscera travel (eg cervical dilation)
with S2-S4 pelvic splanchnics
bulk of bladder wall is made up of
detrusor muscle
internal urethral sphincter consists of
smooth muscle cells extending from detrusor muscle
external urethral sphincter consists of
voluntary striated muscle fibers
external urethral sphincter location
level of pelvic floor
the _________nervous system predominates during bladder filling phase
sympathetic
preganglionic sympathetic nerves for micturition origin
L1-L2
preganglionic sympathetic nerves for micturition
lumbar and sacral splanchnics
where do preganglionic and postganglionic sympathetic nerves for micturition synapse
inferior hypogastric plexus
postganglionic sympathetic nerves for micturition
hypogastric nerves
action of hypogastric nerves
contraction of internal urethral sphincter and relaxation of detrusor muscle
what regulates the micturition reflex
sensory stretch fibers in bladder wall and parasympathetic fibers located in pelvic splanchnics
location of micturition reflex
sacral spinal cord
first sensation for urge to void bladder occurs at what amount of urine
150 ml
sensation of bladder fullness occurs at what amount of urine
400-500 ml
how is sensory information about bladder fullness conveyed
via visceral afferent fibers associated with pelvic splanchnic nerves (parasympathetic)
inhibition of micturition reflex
efferent impulses from the brain inhibit the preganglionic parasympathetic neurons in sacral spinal cord and continue to contract the external sphincter via the pudendal nerve
2 triangles of the perineum
urogenital triangle, anal triangle
pudendal nerve origin
S2-S4
pudendal nerve and artery supply
perineum
divisions of urogenital triangle
deep perineal pouch, superficial perineal pouch
what are the perineal pouches separated by
perineal membrane
what is the deep perineal pouch
a potential space between the pelvic diaphragm and the perineal membrane
what does the deep perineal pouch contain in males
part of urethra, external urethral sphincter, deep transverse perineal muscle, bulbourethral glands
what does the deep perineal pouch contain in females
part of urethra, external urethral sphincter, deep transverse perineal muscle, part of vagina, compressor urethrae, sphincter urethrovaginalis
perineal membrane function
provides support for external genitalia and pelvic organs
what is the superficial perineal pouch
a potential space between the perineal membrane and the perineal fascia
what does the superficial perineal pouch contain
the external genitalia
what is the perineal body
a central tendon into which pelvic floor and perineal muscles attach
perineal body location
midline of perineum
male sets of erectile tissue composing the penis
corpora cavernosa and corpus spongiosum
female sets of erectile tissue
vestibular bulbs, crura of clitoris
thin skeletal muscles that cover the roots of the external genitalia
bulbospongiosum, ischiocavernosum, superficial transverse perineal muscles
bulbospongiosum in males
covers proximal corpus spongiosum (bulb of penis)
bulbospongiosum in females
covers vestibular bulbs
ischiocavernosum in males
covers proximal ends of corpora cavernosa (crus of penis)
ischiocavernosum in females
covers crus of clitoris
superficial transfer perineal muscles course
run transversely across posterior border of urogenital triangle from ischial tuberosity to insert into perineal body
what muscles insert onto perineal body
bulbospongiosum, external anal sphincter, superficial transverse perineal
male sympathetic action in ejaculation
contraction of smooth muscle of epidydimal ducts, vas deferens, seminal vesicles, prostate
pudendal nerve origin
ventral rami of S2-S4
pudendal nerve action
sensory and motor to perineum
pudendal nerve course
exits greater sciatic foramen, passes over sacrospinous ligament, enters lesser sciatic foramen under sacrotuberous ligament to enter pudendal canal
pudendal canal aka
Alcock’s canal
nerve block in vaginal deliveries
pudendal
method of giving pudendal nerve block
transvaginally or transperineally
location of pudendal nerve block
1 cm anterior and medial to ischial spine
pathway for contraction of detrusor muscle
visceral afferents running with pelvic splanchnics stimulate preganglionic parasympathetic neurons in sacral spinal cord
pathway for conscious desire to urinate
visceral afferents running with pelvic splanchnic nerves stimulate ascending pathways to brain
pathway for conscious urination
descending pathways from brain inhibit sympathetic output via hypogastric plexus to allow for relaxation of internal urethral sphincter and stimulate parasympathetics to contract detrusor muscle
pathway for voluntary relaxation of external urethral sphincter
descending signals from brain inhibit pudendal nerve activity