Perineum Flashcards
What are the boundaries of the perineum?
Roof = skin Floor = pelvic diaphragm Anterior = pubic symphysis Lateral = ischial tuberosities Posterior = coccyx
What is the urogenital triangle and what are its borders?
It is the anterior triangle of the perineum.
Anterior = Pubic symphysis
Posterolaterally = ischial tuberosities
Inferior = perineal membrane
Where is the anal triangle located and what are its borders?
It is the posterior triangle of the perineum.
Antero/Lateral = Ischial tuberosities, obturator internus muscle, sacrotuberous ligaments
Posterior = Coccyx
Roof = pelvic diaphragm
What is within the anal triangle?
Anal canal, ischioanal fossa, pudendal canal
Where is the neurovascular bundle of the internal pudendal artery, vein, and nerve located?
Pudendal canal.
Where is the perineal membrane located and what are the borders?
It fills the urogenital triangle.
Anterior and lateral = pubic arch
Posterior = no border! but attaches to perineal body
Where can one find the levator ani muscle and coccygeus muscle?
In the pelvic floor of the pelvic diaphragm.
Where is the superficial perineal pouch located? What does it contain, for males and for females?
It is located superior to the perineum membrane and below the perineal fascia.
Males: Root of penis (bulb and crura), ischiocavernosus, superficial transverse perineal, and bulbospongiosus muscles, and spongy urethra
Famales: clitoris, greater vestibular glands, bulbs of vestibule, ischiocavernosus, bulbospongiosus, and superficial transverse perineal muscles
Where is the deep perineal pouch located? What does it contain in both men and women?
It is located inferior to the perineal membrane and superior to the pelvic diaphragm.
Males: external urethral sphincter (sphincter urethrae membranacea), part of urethra, deep transverse perineal muscle, bulbo-urethral gland, nvb to dorsum of penis
Females: external sphincter of urethra (sphincter urethrovaginalis), urethra, smooth muscle, nvm to clitoris
Where is the anal canal located? What 3 structures does it contain?
It is within the anal triangle, between the rectum and anus. It contains the anal columns, anal valves, and anal sinuses.
What is the pectinate line?
The upper 2/3 (endoderm) of the canal is separated from the lower 1/3 (ectoderm) anal pit by the pectinate line.
What supplies the area above the pectinate line in the anal canal? What supples the area below the line? What are the innervations of this area?
Above: superior rectal artery and vein - from IMA and into IMV; autonomic inferior hypogastric plexus
Below: internal rectal artery and vein - from inferior pudendal artery and into internal pudendal vein; inferior anal and rectal nerves off of pudendal nerve
Where is the internal anal sphincter and is it voluntary or involuntary?
It is around the anal canal - upper 2/3 - and is involuntary.
Where is the external anal sphincter and is it voluntary or involuntary? What is its innervation?
It is found around the internal anal sphincter and is voluntary. It is innervated by the inferior rectal branch of the pudendal nerve.
Where are the superior rectal artery and vein located?
In the anal columns of the anal canal.
