Exam 3: pelvis & perineum Flashcards
contents of pelvis major
lumbar nerve plexus sympathetic trunk lower ilium cecum appendix sigmoid colon upper rectum common iliac vessels ureter psoas major/minor mm iliacus mm
pelvic diaphragm
- located in pelvis minor
- closes floor of inferior bony pelvis
- supports pelvic viscera
- consists of:
- levator ani
- iliococcygeus
- pubococcygeus (medial fibers attach to rectum, vagina, prostate)
- puborectalis
- pubovaginalis
- levator prostate
- levator ani
- coccygeus (ischiococcygeus)
contents of pelvis minor
urinary bladder reproductive organs rectum, anus lumbar plexus sacral plexus sacral sympathetic trunk external, internal iliac vessels obturator internus piriformis pelvic diaphragm
5 functions of pelvic diaphragm
- support viscera
- sphincteric control
- sexual function
- stabilize
- helps pump lymphatic system
pelvic diaphragm innervation
coccygeus: S4,5
iliococcygeus: nerve to pelvic diaphragm S3,4
pubococcygeus: nerve to pelvic diaphragm S3,4
sacral plexus
lumbosacral trunk: ventral rami L4,5 of lumbar plexus
ventral rami S1-4
6 nerves from lumbar plexus that enter pelvic region
*iliohypogastric N not in pelvis
- ilioinguinal: L1
- genitofemoral N: L1,3
- lateral femoral cutaneous N: L2,3
- femoral N: L2,3,4
- obturator N: L2,3,4
- lumbosacral trunk: L4,5
8 nerves from sacral plexus that enter pelvic region
- sciatic N: L4,5 S1,2,3
- superior gluteal N: L4,5 S1
- inferior gluteal N: L5,S1,2
- Nerve to quadratus femoris: L4,5 S1
- Nerve to obturator internus: L5 S1,2
- pudendal N: S2,3,4
- S = ext genitalia
- M = muscles of perineum, ext anal sphincter
- N to piriformis:S1,2
- N to pelvic diaphragm: S3,4 (levator ani, coccygeus)
autonomic nerves to pelvic viscera
sympathetic: via lumbar & sacral splanchnic nerves
parasympathetic: via pelvic splanchnic nerves
pelvic urinary structures
- distal part of ureter
- urinary bladder:
- females: inf & ant to uterus, ant to vagina
- males: superior to prostate, ant to seminal vesicles, ampulla of vas deferens and rectum
- urethra
- females: passes through UG diaphragm to vestibule of vagina
- males: passes through prostate (prostatic urethra) then UG diaphragm (membranous urethra) before entering penis (spongy urethra)
structures of male reproductive system that lie in pelvic cavity
vas deferens
seminal vesicles
prostate gland
testis and epididymis
Develop in abdomen, descend into scrotum
- scrotum: outer skin, inner fascia and dartos mm (smooth mm) –> contracts skin
- cremaster mm: elevates testis toward pelvis to maintain testicular temp
- seminiferous tubules: sperm development
- epididymis: outer surface of testis
- head,body, tail –> vas deferens
continual of abdominal layers to scrotum
- external oblique aponeurosis: external spermatic fascia
- internal oblique aponeurosis: cremaster mm
- transverse abdom: nothing
- transversalis fascia: internal spermatic fascia
3 cylinders of erectile tissue
ventral (1): corpus spongiosum *bulb of penis (prox part of corpus spongiosum) *glans (distal part) dorsal (2): corpus cavernosum *crus of penis (@ pubic ramus) *deep A
female reproductive system
1.clitoris
within pelvic cavity: post to urinary bladder, ant to rectum
- vagina
- uterus
- uterine tubes
- ovaries
ovaries
- lateral to uterus, inferior to fibriae of uterine tubes
- ovarian lig: connects each ovary to uterus
- suspensory lig:
- connects each ovary to pelvic brim
- ovarian vessels, lymphatics, nerves
referred pain: LB, inguinal region and thigh
*ovarian cysts, uterine fibroid, pelvic inflammatory disease, endometriosis, uterovaginal prolapse
perineum boundaries
ant: pubic symphysis
post: tip of coccyx
lateral: pubic arch, ischial tuberosities, sacrotuberous lig
sup: pelvic diaphragm
- line connecting ischial tuberosity
- urogenital triangle (anteriorly)
- anal triangle (posteriorly)
median part of anal triangle (perineum)
- anal canal/opening
* terminal part of large intestine: extends from rectum–>anus
* internal anal sphincter: smooth mm, pelvic parasympath N
* external anal sphincter: skeletal mm, inf rectal N from pudendal N - perineal body: small fibrous mass
* females: between anus, vagina
* males: between anus, bulb of penis
* muscle attachments:- superficial/deep transversus perinei
- bulbospongiosus
- external anal sphincter
3.anococcygeal lig
ischioanal fossa of anal triangle
borders:
- medial: anal canal, sphincters, anus
- laterally by: obturator internus mm & fascia
- pudendal canal: pudendal N, internal pudendal A & V
- pudendal N –> inf rectal N –>ext anal sphincter, skin around anus
- anterior: urogenital triangle
- posterior: sacrotuberous triangle
urogenital triangle spaces
superficial & deep perineal space divided by perineal membrane
superficial perineal space of UG triangle
ischiocavernosus mm
bulbospongiosus mm
superficial transversus perineal mm
deep perineal space of UG diaphragm
sphincter & compressor urethrae mm
deep transversus perineal mm (ischial rami to perineal body)
urethra passes through UG diaphragm
urogenital nerves
- perineal N:
* branches to superficial and deep mms of UG triangle
* post scrotal or labial N in superficial space- cutaneous to post scrotum or labia majora
- dorsal N of penis or clitoris
* enters deep perineal space
* innervates dorsum and glans of penis or clitoris
**perineal N and dorsal N are divisions of pudendal N
male anal triangle and superficial space of UG triangle
- ischiocavernosus mm
- bulbospongiosus mm
- superficial transversus perineal mm
- anococcygeal lig
- perineal body
female anal triangle and superficial space of UG triangle
- ischiocavernosus mm
- bulbospongiosus mm
- superficial transversus perineal mm
- anococcygeal lig
- external anal sphincter
- anus
male anal triangle and deep space of UG triangle
- perineal body
- external anal sphincter
- deep transverse perineal mm
- sphincter urethrae mm
