Pelvis & Pelvic Floor Flashcards
What are the 2 regions of the pelvis separated by the pelvic rim?
1) False pelvis – above pelvic brim
- pelvic inlet continuous with abdominal cavity
- greater pelvis
2) True pelvis – below pelvic brim
- pelvic outlet closed off below by muscular pelvic floor
- lesser pelvis
What are the components of the pelvic girdle?
- 1 sacrum = 5 fused sacral vertebrae
- 2 os coxae = ilium, ischium & pubis
Explain Sexual Dimorphism of Pelvis.
- Oval pelvic brim in ♀ vs. heart-shaped in ♂
- shorter pubic symphysis in ♀
- much wider pubic arch in ♀
- more flared iliac wings (alae) in ♀
- ischial tuberosities farther apart in ♀
- sacrum shorter & less curved in ♀
*All for accommodation of childbirth
What are the specific features of the female pelvis?
♀
Oval to rounded pelvic inlet = superior pelvic aperture
- pubic arch is wider with a subpubic anlge >80
- obturator foramen is oval
- acetabulum is small
What are the specific features of the male pelvis?
♂
Males have thicker and heavier structure related to heavier build and larger muscles of men
- greater pelvis is deeper (no childbirth)
- lesser pelvis is narrow and deep
- pubic arch is naroow with a subpubic arch <70
- obturator foramen is round
- acetabulum is large
What are the ligaments of the pelvis?
- pubic symphysis - connects 2 pubic bones
- Ant. sacroiliac lig.
- Post. sacroiliac lig.
- sacrotuberous lig.
- sacrospinuos lig.
- obturator membrane - closes off obturator foramen(lower border of obturator canal
- interosseous lig.
Where is the sacrotuberous lig.?
- ischial tuberosity to sacrum/coccyx
- lower border of lesser sciatic foramen
Where is the sacrospinuos lig.?
- ischial spine to sacrum/coccyx (lower boundary of greater sciatic foramen)
What are the Muscles of Pelvic walls?
1) Piriformis m.
2) Obturator internus
What are the specifics of the Piriformis m.?
- anterior sacrum to greater trochanter
- passes behind greater sciatic notch
- closes off posterior/superior pelvic outlet
- arises in pelvis to act on hip joint
- passes thru greater sciatic foramen
- S1, S2
What are the specifics of the Obturator internus m.?
- obturator foramen to greater trochanter
- covered with thick fascia & attaches to levator ani as tendinous arch
- arises in pelvis to act on hip joint
- passes thru lesser sciatic foramen
- L5, S1
What separates the pelvic cavity from the perineum, formed by muscles and fascia?
The Pelvic Floor/Diaphragm
What muscles are the largest component of the pelvic diaphragm?
The 3 Levator Ani muscles:
- Iliococcygeus
- Pubococcygeus
- Puborectalis
What are the other muscles of the pelvic diaphragm?
Coccygeus mm.
Assisted by piriformis & obturator internus mm.
What is the perineum?
A diamond shaped region between thigh, made up of 2 Δs
What 2 Δs make up the perineum?
1) Urogenital Δ
- passage of urinary & genital systems
- deep trans. perineal mm. or UG diaphragm
2) Anal Δ
- passage of rectum & anus
- pelvic floor mm. or pelvic diaphragm
What are the specifics of the Deep Transverse Perineal mm. /UG Diaphragm?
- Anterior/inferior to pelvic diaphragm
- Composed of deep transervse perineal mm.
- Extends between 2 pubic arches
- Attaches posteriorly to perineal body
- Blends with sphincter mm. of urethra and vagina(♀)
What/where are the ureters?
- transport urine from kidneys to bladder
- cross ext. iliac vessels & descend into pelvis
- travel to posterolateral aspect of urinary bladder
- Female: uterine a. crosses ureter
- Male: ductus deferens crosses ureter
What the specifics of the urinary bladder?
- stores urine prior to expulsion thru urethra
- consists of smooth m. = detrusor urinae
- covered by peritoneum & supported by pelvic floor
What are the specifics of the female urethra?
- ~ 3.5 – 4 cm
- Pierces ant. portion of UG diaphragm between bladder and external urethral orifice
What are the specifics of the rectum?
- located in true pelvis superior to pelvic floor
- normally constricted by puborectal sling - U-shaped puborectalis m.
What are the specifics of the Anal Canal?
- emerges in anal Δ inferior to pelvic floor
- continuous with rectum at anorectal junction & produces curvature at anorectal junction (perineal flexure)
- relaxes to allow defecation
What are the Male Pelvic Viscera?
- Penis
- Testes -primary male reproductive organs, housed in scrotum
- Spermatic cord - fascial sheath derived from anterior abdominal wall, from inguinal canal into scrotum, surrounds ductus deferens, testicular vessels & nn.
- ductus (vas) deferens
- reproductive glands:
1) seminal vesicles - joins vas def, forms ejaculatory ducts, empty into prostatic urethra
2) prostate gland - walnut sized, btwn bladder & UG diaphragm
3) bulbourethral (Cowper’s) gland - 2 pea sized, within UG diaphragm, empty into penile urethra
What are the specs on the ovaries?
- primary female reproductive organs
- produces ova & female hormones - 1 ovum released per menstrual cycle
- encapsulated and housed in true pelvis
What are the specs on the uterine (fallopian) tubes?
- muscular tubes for transport of ovum to uterus
- open channels from peritoneal cavity to uterus- isthmus, ampulla infundibulum & fimbriae
What makes up the adnexa?
ovaries + uterine tubes + uterine ligaments
What are the specs on the uterus?
- ~7 cm long (may enlarge 20x during pregnancy)
- usually anteverted & at right angle to vaginal canal
- position changes with full bladder & pregnancy
What are the specs on the uterine cervix?
- inferior neck of uterus protruding into vaginal canal
- opens to vagina as external os & uterus as internal os
What are the specs on the vaginal fornix?
- circular gutter surrounding cervix
- deeper post. than ant.
What are the uterine ligaments?
1) Suspensory lig. - peritoneum covering ovarian vessels & nn.
2) Broad lig. - peritoneum covering uterus and adnexa
3) Ovarian lig. - anchors ovary to uterus
4) Round lig. of uterus - continuation of ovarian lig., passes thru inguinal canal to fuse with labia majora
