21: pelvis and perineum Flashcards
Where would the urethra be torn in order to have fluid accumulation in lower abdomen and around penis and scrotum?
The urethra would have been torn as it passed the perineum membrane.
What fascial continuities allowed urine to accumulate in the spaces of the lower abdomen and penis and scrotum?
Scarpas fascia (anterior abdominal wall) Membranous layer of superficial penis fascia Dartos fascia (scrotum) Colle’s fascia (perineum)
Why does urine not go into thigh?
Colle’s fascia (membranous superficial fascia of perineum) attaches to ischiopubic rami and to the perineal membrane
Why does urine not go into the anal triangle?
Scarpa’s fascia attaches to fascia lata of the thigh
What neurovascualr structures could be damaged by an abscess in the iscioanal fossa?
pudendal nerve and internal pudendal vessels; inferior rectal nerves and vessels
two anatomical landmarks for local pudendal nerve block?
ischial spine ischial tuberosity
how does a perineal abscess start?
infection within anal sinus
What are the major features of the anal canal?
anal column pectinate line anal valves anal sinus
Epithelium above pectinate line
simple columnar
Epithelium below pectinate line
Stratified squamous
Innervation above pectinate line
VA
Innervation below pectinate line
SA
Why are external hemorrhoids more painful?
They occur below pectinate line, meaning they have SA innervation.
Lymphatic drainage above pectinate line
to iliac nodes
Lymphatic drainage below pectinate line
Inguinal nodes