Pelvic Muscles Flashcards
Perineal Body?
fibromuscular mass that serves as an attachment point for muscles coming from all directions towards the central location.
What are the superficial perineal muscles? (3).. where are they located?
what are they innervated with?
superficial to the perineal membrane
Superficial Transverse Perineal M. –> they’re only like strips of fiber coming from the lateral edges going to the perineal body. It keeps the perineal body midline!
Bulbospongiosus M.
Ischiocavernosus M.
all three innervated by deep perineal nerves.
Bulbospongiosus and Ischiocavernosus M. on the male?
thin layers of skeletal muscle on the erectile tissue.
these make them seem like they’re huge, beefy muscles. they’re not.
what is erectile tissue?
in males and females, there are 3 pieces of erectile tissue
in the male, it makes up the penis. female it’s the clitoris and paired bulbs of the vestibule.
erectile tissue is like a dense sponge. when you force blood into this and you don’t let the blood back out, that sponge becomes erect. that’s erectile tissue.
What are the 3 parts of erectile tissue in the male? anatomically where are they?
what are they called in different regions?
2 paired dorsal cylinders. dorsal = top of the penis
- proximally they’re called “crura”
- heading distally, they’re called the corpus cavernosum (Plural is corpora cavernosum)
1 unpaired ventral cylinder = bottom of the penis
- proximally it’s the bulb of the penis
- middle it’s the corpus spongiosum
- distal its called the Glans Penis
What are the 3 erectile tissue for females?
1 unpaired clitoris –> 3 parts (glans clitoris, body, and then the crura of the clitoris)
2 bulbs of the vestibule (either side of the vaginal vestibule).
bulbospongiosus in females?
bulbs of the vestibule –> made of erectile tissue.. they have a thin layer of muscle on them called “bulbospongiosus m”
action of Bulbospongiosus in males?
females?
what about both?
compressing venous drainage, expel drops of urine, semen in the urethra out of the urethra.
they can compress vaginal vestibule and vagina (because they’re on the outside of the vestibule).
hold the perineal body in place from the anterior direction
ischiocavernosus on the male?
female?
male or female, which is smaller?
thin layer of muscle!
goes from the ischium to the corpus cavernosum (or on the crura of the penis then to the corpus cavernosum).
similar –> but instead of crura of the penis, they’re on the crura on the clitoris. smaller on the female because the crura of the clitoris is smaller than the crura of the penis
action of Ischiocavernosus?
compressing venous drainage.
What are the urogenital diaphragm muscles? (3)
where are these just deep to?
External Urethral Sphincter M.
Deep Transverse Perineal M. (in the female, this is smooth muscle, in the male it’s skeletal muscle)
compressor Urethrae M. (extends from the wall to hold the urethral sphincter)
urethrovaginal sphincter m. (in females, encircle the vagina)
these are both just deep to the perineal membrane
good to know about the deep transverse perineal m?
in the female, this is smooth muscle, in the male it’s skeletal muscle
What innervates the external urethral sphincter m?
male = dorsal nerve of the penis female = dorsal nerve of the clitoris
NOT DEEP PERINEAL NERVES
What are the anal muscles? innervated by?
what is the external innervated by?
External Anal Sphincter M. (skeletal) –> holds the perineal body in place (we can control this)
innervated by inferior rectal N.
Internal Anal Sphincter M. (smooth) (can’t control this) –> pelvic splanchnic nerves
Pelvic Diaphragm does what?
separates the pelvis from the perineum.
