Pelvis and Perineum 4 Flashcards
Where does the perineum lie?
Inferior to the pelvic diaphragm
What is the most inferior portion of the trunk?
Perineum
What can the perineum be divided into?
Two triangle areas
Which bony landmarks create the boundaries of the perineum?
Pubic symphysis
Ischial tuberosity
Coccyx
What are the names of the 2 triangles?
Urogenital triangle
Anal triangle
What bony prominence separates the 2 triangles?
Ischial tuberosity
What stretches between the right and left side of the pubic arch?
A thin sheet of deep fascia
What is the name of the thin sheet of deep fascia that stretches between the right and left side of the pubic arch?
Perineal fascia
What is the main action of the external anal sphincter?
Voluntary control of defaecation
What is the external anal sphincter innervated by?
Branches of the pudendal nerve (S2-S4)
What is the main action of the superficial transverse perineal?
Constricts vagina and urethra
Maintains urinary continence
What is the superficial transverse perineal innervated by?
Pudendal nerve (S2-S4)
What is the main action of the Deep transverse perineal?
Fixation of the perineal body
Support the pelvic floor
What is the innervation of the deep transverse perineal?
Pudendal nerve (S2-S4)
What is the main action of the external urethral sphincter?
Compress urethra to maintain urinary continence
What is the innervation of the external urethral sphincter?
Branches of the Pudendal nerve (S2-S4)
What is the main action of the bulbospongiosus (Male)?
Expel remaining urine from the urethra after the bladder has been completely emptied
What is the bulbospongiosus innervated by?
Branches of the pudendal nerve (S2-S4)
What is the main action of the Bulbospongiosus (female)?
Clitoral erection and the contractions of orgasm
Closes the vagina
What is the main function of the Ischiocavernosus in Males?
Maintains penile erection
What is the main function of the Ischiocavernosus in females?
Maintains clitoral erection
What are 2 important muscle attachments in the perineum?
Perineal body
Anococcygeal body
What are the names of the 2 layers of fascia that are important for providing support for the pelvic organs?
Superior fascia
Pre-spetal
Which 2 structures pierce up through the pelvic diaphragm?
Levator ani
Coccygeus muscle
Is the urethra longer in males or females?
Males
What are the 3 parts of the male urethra?
Prostatic Urethra
Membranous urethra
Spongy urethra
What is the widest part of the male urethra?
Prostatic urethra
What is the narrowest part of the male urethra?
External urethral meatus
Why is he prostatic urethra the widest?
Because it is at risk of being narrowed by enlargement of the prostate