Male and Female Perineum Flashcards
Where does the perineum lie?
Lies inferior to pelvic diaphragm and is most inferior portion of the trunk
What bony landmarks create the boundary of the perineum?
Pubic symphysis
Ischiopubic rami
Coccyx
What are the 2 triangles which make up the perineum and what bony prominence separates them?
Urogenital and anal triangle
Ischial tuberosities
What is the fascia stretching between the right and left pubic arch?
Superficial perineal fascia
What is the main action of the external anal sphincter?
Voluntary muscle which surrounds lower 2/3rds of the anal canal
What is the innervation of the external anal sphincter?
Branches of the pudendal nerve - S2-4
What is the main action of the superficial and deep transverse perineal muscle?
Fixation of perineal body and supports the pelvic floor
What is the innervation of the superficial and deep transverse perineal muscle?
Branches of the pudendal nerve
What is the main action of the external urethral sphincter?
Compresses urethra to maintain urinary continence
Supplied by pudendal nerve
What is the main action of the bulbospongiosus muscle in males?
Facilitates urination, ejaculation and erection
Supplied by pudendal nerve
What is the main action of the bulbospongiosus muscle in females?
Erection of the clitoris and emptying the greater vestibular glands
What is the main action of the isciocavernosus muscle in males?
Maintains erection of the penis
Supplied by the pudendal nerve
What is the main action of the isciocavernosus muscle in females?
Maintains erection of clitoris
Which structures pierce through the pelvic diaphragm?
Urethra and anal canal
Vagina in females
What are the 3 parts of the male urethra?
Prostatic
Membranous
Penile
What is the widest part of the male urethra?
Prostatic
Widest and most dilatable
What is the narrowest and least dilatable part of the male urethra?
Membranous
As surrounded by the external urethral sphincter
What is the male external genitalia?
Testes, scrotum and penis
What is the terminal part of the penis?
Glans penis
Covered by the prepuce (foreskin)
What fascial layer covers the corpus cavernosa?
Tunica albuginea
What is the urethra transmitted through in males?
Corpus spongiosum
What is the majority of the erectile tissue in the penis?
Corpus cavernosum
What supplies the sensory innervation the penis?
Dorsal nerve of the penis - branch of the pudendal nerve
What is the green area?
Corpus cavernosum
What is the yellow area?
Corpus spongiosum
What are the contents of the vulva?
Mons pubis, labia majora, labia minora, vestibule, Bertholin’s glands and clitoris
What is the vulva supplied by?
Pudendal nerve
Internal pudendal artery
What is the vestibule?
Enclosed by the labia minora and contains the terminal aspect of the vagina and the urethra
What is the clitoris comprised of?
2 crura, which meet in the midline to form the body
Projects downwards to the prepuce and glans which lie in the anterior labial commissure
How long is the anus?
Approx. 4cm
What is the control under the internal and external sphincter?
Internal - autonomic
External - voluntary
What are the 2 fat containing fossa which lie inferior to the pelvic floor and lateral to the anal canal?
Ischio-anal fossa - allows the anal canal to expand during defaecation
What is A?
External anal sphincter
What is B?
Internal anal sphincter
What is C?
Ischio-anal fossa
What enters the ischio-anal fossa through the lesser sciatic foramen?
Neurovascular bundle - pudendal nerve, inferior rectal vein and inferior rectal artery
What does the neurovascular bundle in the ischio-anal fossa supply?
External urethral sphincter, external anal sphincter and levator ani
