wk 4 8 - anatomy - faecal continence - distal GI Flashcards
number of lateral folds in rectum
3
what can be palpated in a female rectal exam
cervix
likely area for ascites to collect in females/males
rectouterine pouch (pouch of douglas) rectovesical in males
3 parts of hip bone
pubic
iisheum
ileum
muscle which forms most of pelvic diaphragm (with fascial coverings), name 3 parts
levator ani
puborectalis (most important) (surrounds pubic)
pubococcygeus
iliococcygeus
importance of levator ani muscle
prevents organs being pushed inferiorly and fall out (during cough,sneezing)
2 nerves supply the levator ani
Pudenal S2,3,4 (keeps guts off floor)
nerve levator ani (s3,4) (branch of sacral plexus)
contraction of puborectalis has what effect on rectum
relaxes the anorectal angel, acting as a sphincter and allowing foecal continence
internal anal sphincter
thickening of 3 muscle layers of colon
external anal sphincter
solid disc of muscle
t/f internal anal sphincter is smooth muscle
true
external - skeletal
where is internal anal sphincter located in anal canal
superior 2/3
t/f contraction of internal inhibits parasympa
true
internal - contracted all the time, relaxes in response to distension of rectal ampulla
what stimulates contraction of external anal sphincter
pudendal nerve
what controls the structures found in perineum? in pelvis? what separates the 2
perineum - somatic motor and sensory (body wall)
pelvis - sympa,para,visceral afferent (body cavity)
lavter ani - above = pelvis, below = perineum
where are parasympa fibres for rectum from
S2-4 (visceral afferents also in S2-4) (hindgut)
t/f sympa fibres from T12-L2
true
somatic motor from
S2,3,4 (pudenal nerve - keeps guts off the floor)
outline parthay of pudendal nerve to external anal sphincter
branch of sacral plexus -S2,3,4 nterior rami
exits pelvis via greater sciatic foramen
enters perineum via lesser sciatic foramen
supplies structures of perineum
during labour which muscle is likely to tear
puborectalis
pudendal nerve may also be damaged
pectinate line
marks junction between part of embryo which formed GI tract
above = endoderm
below = ectoderm (outer lining of embryo)
t/f lesions above pectinate line will be more painful than below
false - feel less localised
nerves supplying above pectinate line
autonomic
below = somatic, pudendal
t/f lymphatics follow the veins in body
false
follows arteries
difference in rectal varices and haemorrhoids
varices - portal hypertension, dilation of veins
haemorrhoids - prolapses of rectl venous plexuses (rapid pressure - constipation, straining, pregnancy)
check blood pressure to differentiate
internal or external haemorrhoid - which one would be more painful
external (requires anaesthetic)
