Perineum Flashcards
Structures that form the pelvic diaphragm
- Levator ani muscles
- Small coccyges
- covering fasciae
Perineum is bonded laterally by________, posteriorly by ________ and anteriorly by __________?
Laterally - ischial tuberosity
Posteriorly - coccyx
Anteriorly - pubis symphysis
Nerve supply skin around the anus
Hemorrhoidal nerve/ inferior rectal nerve
Bounded behind by the tip of the coccyx on each side by the ischial tuberosity and sacrotuberous ligament, overlapped by the border of gluteus maximus
Anal triangle
Fibrous tissue lying between the anal canal and the coccyx
Anococcygeal body
Fascia that closes the urogenital triangle
Perineal membrane
Mucous membrane of the upper half of the anal canal is derived from?
Hindgut
Lymphatic drainage of superior rectal artery
Pararectal nodes and eventually to inferior mesenteric nodes
Mucous membrane of the lower half of the anal canal
Ectorderm of the proctodeum
Nerve supply of external voluntary sphincter, mucous membrane of the lower half and perineal skin
Inferior rectal nerve branch of pudendal nerve
Wedge-shaped space located on each side of anal canal
Ischiorectal fossa
A branch of sacral plexus and leaves the main pelvic cavity through the greater sciatic foramen
Pudendal nerve
Supplies the urogenital triangle and the skin on the surface of scrotum or labia majora
Perineal nerve
A branch of internal iliac artery and passes from the pelvis through the greater sciatic foramen and enters the perineum through the lesser sciatic foramen
Internal pudendal artery
Bounded in front by the pubic arch and laterally by the ischial tuberosities
Urogenital triangle
Varicosities of the superior rectal (hemorrhoidal) vein and are covered by mucous membrane
Internal hemorrhoids/ piles
Varicosities of the tributaries of the inferior rectal vein as they run laterally from the anal margin
External hemorrhoids
Indicates the level where the upper half of the anal canal joins the lower half
Pectinate line
Formed from a thickening of the smooth muscle of the circular coat at the upper end of the anal canal
Internal sphincter
At the junction if rectum and anal canal is the anorectal ring. What muscles are involved in this ring?
- internal sphincter
- deep part of the external sphincter
- puborectalis
Corresponds to the penis of male
Clitoris
Situated at the apex of the vestibule anteriorly
Clitoris
What are the roof of clitoris which are the three muscles of erectile tissue?
- bulb of the vestibule
- right and left crura of the clitoris
It is attached to the undersurface of the urogenital diaphragm and is covered by the bulbospongiosus muscle
Bulb of the vestibule
Consist of two corpora cavernosa covered by their ischiocavernous musvle
Body of the clitoris
A small mass of erectile tissue that caps the body of the clitoris
Glans of the clitoris
Surrounds the orifice of the vagina and covers the vestibular bulbs
Bulbospongiosus muscle
Contraction of this muscle assists in causing the erection of the clitoris
Ischiocavernous muscle
Wedge-shaped mass of fibrous tissue situated between the lower end of the vagina and the anal canal
Perineal body
Corresponds to prostate in male
Paraurethral glands
Pair of small mucus secreting glands that lie under cover of the posterior parts of the bulb of vestibule and labia majora
Greater vestibular glands
Blood supply of vagina
Vaginal artery
Nerve supply of anterior part of vulva
Ilioinguinal nerves and genitofemoral nerves
Nerve supply of posterior part of vulva
Perineal nerves and posterior cutaneous nerves
Venous drainage of vaginal veins
Internal Iliac veins
