8.1 Perineum Flashcards
What are the boundaries of the perineum?
Pubic symphosis, ishiopubic ramus, ischial tuberosity, sacrotuberous ligament, coccyx, anal triangle, urogenital triangle
What is the perineal membrane?
It is a strong supporting membrane that fills the urogenital triangle and has a deep perineal pouch
What are the components of the Eternal urethral sphincter?
External urethral sphincter, compressor urethrae and urethrovaginal sphincter which are all in the deep perineal pouch
What are the two perineal pouches?
Superficial perineal pouch and Deep perineal pouch
What is an example of a superficial urogenital muscle?
Bulbospongiosus is a sphincter skeletal muscle that contracts to expel the last drops of urine
What is the significance of the perineal body?
It provides common site of attachment for muscles of perineum
Describe the Ischio (rectal) anal fossa
Allows distension of rectum and anus during defection, contains fat and interior rectal nerve to external anal sphincter
What is the external anal sphincter?
Smooth muscle thickening with 3 parts of skeletal muscle
What are the 3 parts of the skeletal muscle external anal sphincter?
Deep, Superficial and Subcutaneous parts
What is the main nerve for the perineum?
Pudendal nerve
Where does the Pudendal nerve arise from?
S2-4
What does the nerve specifically supply?
Pelvic floor, peroneum, rectum, levator ani
Where does the nerve enter and exit the pelvic girdle and why?
It enters through the greater sciatic foramen and exits the lesser to avoid compression
