Perineum Flashcards
What are the two triangles of the perineum?
urogenital triangle
anal triangle
Which two structures enclose the perineum
levator ani above, superficial fascia below
The perineal membrane splits the urogenital triangle into which two regions?
superficial and deep perineal pouch
What is the thickened midline structure of the perineum?
perineal body
Which two transverse muscles reinforce the perineal body
superficial and deep transverse perineal muscles
What is the name of the fat filled space in the anal triangle?
ischial-rectal fossa
Which muscle can be found on the side wall of the perineum
obturator internus
Which vessels are found in the pudendal canal
internal pudendal vessel and pudendal nerve
What does the pectinate line of the anal canal demarcate
the internal 2/3, lined by mucus and the external 1/3, lined by skin
What is the vascular supply for the
1) upper 2/3
2) lower 1/3 of the anal canal
1) superior rectal artery and portal venous system
2) inferior rectal artery and systemic venous system
T/F the entire anal canal receives autonomic nervous supply
False, only the upper 2/3. The lower 1/3 gets pudendal, somatic supply
What is the internal anal sphincter innervated by
ANS
What are the three parts of the external anal sphincter
deep, superficial and subcutaneous
Which muscle does the deep external sphincter fuse with
the pubo-rectal sling, part of the pubococcygeus
What are the anterior and posterior anchors of the superficial external anal sphincter
anteriorly to the perineal body, and posteriorly to the coccyx
T/F subcutaneous external anal sphincter blends with the subcutaneous fat
True
T/F All of the sphincters are in the superficial perineal pouch
False, they are all in the deep perineal pouch, anchored to the perineal body
What are the five parts of the male urethra
Pre-prostatic, where internal urethral sphincter is
prostatic, with openings of ejaculatory duct
membranous, in deep perineal pouch
spongy, then penile part
What are the names of the male erectile tissue
corpus cavernosum x2, above the corpus spongeosum
Which erectile tissue surrounds the urethra
corpus spongeosum
What are the muscles covering male erectile tissue
ischial caverosus for CC
bulbospongeosus for CS
Which spinal segments give rise to the pudendal nerve
S2-S4
Describe the course of the pudendal nerve
Starts in the pelvis, then exists via GSF with piriformis, winds back into perineum via LSF, into the anal triangle
What is the first branch of the pudendal nerve
inferior rectal nerve
What is the terminal branch of pudendal nerve
dorsal nerve of the clitoris or penis
the perineal nerve gives which two divisions
motor (deep) division and cutaneous (superficial) division
