Anatomy Flashcards
Perineum
Diamond shaped space between external genetelia and anus
Perineum separated from pelvic cavity by
Pelvic floor
Function of perineum
Urogenital and GIT system;micturition,defecation,SI,childbirth
Anatomical borders of perineum
Ant:pubic symphysis
Post:tip of coccyx
Lat:ischiopubic rami,Ischias tuberosity,sacrotuberous ligament
Roof:pelvic floor/pelvic diaphragm
Base:skin and fascia
Perineum divided into urogenital and anal triangle by imaginary line between
Ischial tuberosity
Surface borders of perineum
Ant;mons pubis females,base of penis males
Lat:medial surface of thigh
Post:superior end of intergliuteal cleft
Anal triangle boundaries
Post:coccyx
Ant:ischial tuberosity transverse line
Lat:sacrotuberous ligament
Contents
Anal aperture – the opening of the anus.
External anal sphincter muscle – voluntary muscle responsible for opening and closing the anus.
Ischioanal fossae (x2) – spaces located laterally to the anus.
Pudendal nerve(somatic fibers to perineum)
Function of ischioanal fossae
Fat,CT allow for expansion of anal canal during defecation
Contents of fossae
Pudendal nerve(pudendal/Alcock canal ——obturator inter US fascia split also has internal pudendal vessels)
Inferior rectal vessels,internal pudendal vessels,perineal branches of post femoral cutaneous nerve
Occasionally Abscess in fossae extend by
Anoccocygeal fossae
Muscle of analtriangle
Obturator internes,external anal sphincter,lavator ani,coccygeus
Water tight seal of anal canal formed by
Corrugator Curtis muscle
Urogenital triangle boundaries
Ant:pubic symphysis
Post:ischial tuberosity
Lat:ischiopubic rami
Functions:urogenital system
Layers of urogenital triangle
Deep perineal pouch(external urethral sphincter,urethra,vagina,males:bulbourethral glands,Deep transverse perineal muscles)
Perineal membrane (urethra,vagina,attaches muscles of external genitalia)
Superficial perineal pouch (erteile tissue that form penis,clitoris,ischiocavernosus,bublospongiosus,superficial transverse perineal muscles,Bartholon glands)
Perineal fascia(deep fascia-xx covers perineal muscles and penis,clitoris,superficial fascai -xxx superficial layer,Cole’s fascia)
Skin(urethral ,vaginal orifices)
Anal triangle has all layers except
Perineal membrane
Perineal body
Fibromuscular mass at junction between urogenital and anal triangle attaches Levator ani,bublospongiosus,superficial deep transverse perineal muscles,external anal and urethral sphincter,acts as tear resistant body in females by supporting posterior vaginal wall against prolapse. Support pelvic floor.
Neurovascular supply to triangles
Pudendal nerve(S2 to S4),Internal pudendal artery(Alcock canal)
Bartholinitis
Infected and inflamed bartholin glands(fluid filled cysts when duct blocked) caused by bacteria staphylococcus spp,es Cheri his coil.
Contents of greater sciatic foramen
Suprapiriformis:Superior gluteal vessels Infpiriformis:Nerve to obturator internus and Quadrat us femoris,inferior gluteal vessels,post femoral cutaneous nerve,sciatic and pudendal nerve
Contents of lesser sciatic foramen
Internal pudendal A,V,pudendal nerve,obturator internus tendon,nerve to obturator internus
Pelvic floor is formed by
Levator ani,coccygeus,fascia covering of muscle
Levator ani muscles
Pubicoccygeus,illiococcocygeus,publrectalis
Pelvic floor nervous supply
Ant s4,pudendal nerve perineal branch S2 to #
S4
Pelvic floor hiatus
Urogenital(urethra,vagina)
Rectal(anal canal)
Function of pelvic floor
Support of a domino pelvic viscera(tonic contraction),resistance to increase in intraabdominal pressure,urinary and fecal continence(relaxation)
Ureteric calculus
Kidney stone
Constrictions of uretr
Ureteropelvic junction,pelvic brim,bladder ureter junction
Damage to ureter can be seen in
Oophorectomy. (Post to ovaries),hyperectomy(ant to uterine artery),post to vas deferens
Neurovasculature of ureter
A:aorta,renal,gonadal
(Pelvic:superior inferior vesical)
N:testicular/ovarian,renal hypo gastric plexus
Sensory supply dermatome of ureter
T11 to L2 ureteric pain