Sept5 M3-Pelvis_Anatomy_lecture_4 Flashcards
boundaries of the urogenital triangle
(will be formed by some boundaries of pelvic outlet)
- pubic symphysis
- ischiopubic rami
- imaginary line between the ischial tuberosities
IRL tilt of the UG triangle when pelvis properly tilted
horizontal. surface of triangle facing down.
3 parts of levator ani (extend into the UG triangle)
- iliococcygeus (most lat and post)
- pubococcygeus
- puborectalis (most medial and ant)
levator ani and coccygeus muscle relation to SS ligament
are deep to it in the body so are anterior to SS lig
iliococcygeus comes off what bone
ischial spine
perineal membrane def
thin sheet of tought CT (fascia) covering the UG triangle
- dividing point between UG and anal triangles so dividing point between rectum and vagina (**SAME BOUNDARIES AS UG TRIANGLE)
- urethral opening (hole in perineal membrane) for urethra
- vaginal opening (hole in perineal memb) post to urethral one
perineal body def
center point of the diamond formed by the UG and anal triangles.
-small mass of fibrous tissue between rectum and vagina and at midpoint between ischial tuberosities
perineal body relations
- anterior: vestibule (opening) of the vagina OR bulb of the penis
- posterior: anal canal
muscles attaching to the perineal body
- levator ani
- superficial and deep transverse perineal muscles
- bulbospongiosus muscle
perineal body clinical significance
can be damaged during difficult childbirth. consequence = possible prolapse of pelvic viscera
deep and superficial perineal pouch
pouches (spaces) deep and superficial to the perineal membrane
structures in deep perineal pouch in the male
- membranous urethra (part of urethra between prostatic and penile)
- bulbourethral (Cowper’s) glands on each side of membranous urethra, pierce through perineal membrane to enter penile urethra
- external urethral sphincter (muscle). voluntary control
- deep transverse perineal muscle (thin). O and I = right pubic rami to left pubic rami. same for superficial
- perineal nerves and vesseks (in back of perineal membrane)
origin of perineal nerve
pudendal n
origin of perineal vessels
internal pudendal a (takes same path as pudendal n). when it reaches the back of the UG triangle, it gives superficial and deep branches)
bulbourethral (Cowper’s) glands fct
- secrete pre-ejaculate to lubricate the urethra
- neutralize traces of acidic urine
structures in the deep perineal pouch in the female
- proximal urethra
- external urethral sphincter (muscle)
- vagina
- deep transverse perineal muscles
- perineal vessels and nerves
- no glands*
structures of superficial perineal pouch in the female (except muscles and neurovascular supply)
- vestibule (opening of vagina and urethra)
- greater vestibular glands (Bartholin’s) (give ducts opening on side of vagina)
- bulb of the vestibule (2 bulbs of erectile tissue lat to vestibule and extending anteriorly) (in men, becomes corpus spongiosum)
- fourchette (posterior portion of the vagina)
- urethral orifice
- vaginal orifice
- body of clitoris (containing corpora cavernosa)
- crura of the clitoris (lying against the ischiopubic rami). come together at midline to form body of clitoris
greater vestibular glands (Bartholin’s)
- secrete mucus to lubricate the vagina
- homologous to BU glands in male
external genitalia in the female
- mons pubis (over pubis symphysis)
- clitoris (ant)
- labia majora
- labia minora
- anus
muscles in the superficial perineal pouch in the female
- superficial transverse perineal m (along back border of perineal membrane)
- ischiocavernosus m (covering the crura of the clitoris)
- bulbospongiosus m (muscle surrounding the vestibule). in the male, the bulb of the penis is continus with corpus spongiosum so name remained)
neurovascular supply in superficial perineal pouch in female
- perineal nerves (from pudendal n splitting in superficial and deep)
- perineal vessels (front internal pudendal a and v)
path of pudendal n, a and v
- out of greater sciatic foramen with inferior gluteal
- reach gluteal region
- come back underneath in perineum (wraps around ischial spine)
- go below piriformis
- reach back of UG triangle
- give superficial and deep branches
superficial perineal pouch structures in the male except neurovascular
- crura of the penis (crus on each side along ischiopubic rami) continuous with the corpora cavernosa
- bulb of the penis
- ischiocavernosus m (covers the crura)
- bulbospongiosus m (covers the bulb of the penis)
- penile urethra
- superficial transverse perineal m.
- (root of the penis, basically whole base with crura, bulb and their muscles)
- (shaft of the penis with the corpora cavernosa and spongiosum)
neurovascular supply of superficial perineal pouch in the male
- perineal vessels
- perineal nerves
muscles in shaft (body) of penis
none
bottom vs top of penis
bottom = corpus spongiosum (from bulb) with penile urethra (which is therefore enclosed by bulb and corpus spongiosum)
top = 2 corpora cavernosa (from
crura)
*and glans at end of the penis, top and bottom
end of urethra name in male
external urethral meatus (orifice)
internal urethral orifice is where
bladder
start and end landmarks of the membranous urethra (male)
bottom of prostate to perineal membrane. surrounded by external urethral sphincter
(important) structure in middle of corpora cavernosa
deep artery (comes from internal pudendal a) *no venule, vein
veins and arteries (other than deep a) in the penis
- deep dorsal and superficial dorsal veins
- dorsal penile artery
Buck’s fascia is what
deep fascia surrounding the penis and separating the deep and superficial dorsal veins
Dartos fascia is where in the penis
fascia surrounding the penis and that is superficial to the superficial dorsal veins. skin comes right after it
Tunica albuginea is where in the penis
deep to the deep dorsal vein
order of structures surrounding the penis
- tunica albugenia
- deep dorsal vv AND DORSAL PENILE ARTERY
- Buck’s fascia
- superficial dorsal vv
- Dartos fascia
- skin
how erection is maintained
- penis filled with blood and this compresses on the thick non elastic Buck’s fascia (superficial to deep dorsal v).
- deep forsal v is compressed and blood can’t leave
structures surrounding the scrotum in the male (in to out)
- tunica vaginalis (from obliterated processus vaginalis = peritoneum coming in inguinal canal)
- internal spermatic fascia (from transversalis fascia)
- cremaster muscle (from internal oblique)
- external spermatic fascia (from external oblique)
- Dartos fascia (same as one in penis) (continuous with Scarpa’s fascia in abdomen) and muscle
- skin
Scarpa’s fascia is what
membranous layer of the superficial fascia in the abdomen (continuous with superficial fascia of the penis and scrotum = Dartos)
Colle’s fascia is what
piece of the Dartos fascia that extends in the pelvis to form the superficial perineal fascia
perforation of urethra without penetration of Buck’s fascia gives what
urine accumulates around the shaft (body) of the penis between Buck’s fascia and tunica albugenia
perforation of urethra with penetration of Buck’s fascia gives what
urine in scrotum and all the way up the abdominal wall
- between buck’s fascia and dartos fascia in the penis body region
- between buck’s fascia and Scarpa’s fascia in the dorsal penis shaft region
- between Buck’s fascia and Dartos fascia of scrotum and between Buck’s fascia and Colle’s fascia for region of ventral penis shaft
