Clinical Anatomy of Faecal Continence

Question 1

distal GI tract

Answer 1

colon
rectum
anal canal
anus

function is to excrete stool

Question 2

control of the excretion of faeces

Answer 2

holding area - rectum

normal visceral afferent nerve fibres to sense fullness

functioning muscle sphincters around distal end
appropriate contraction to avoid defection and to relax

normal cerebral function to control the appropriate time to defecate

affected by neurological pathology

Question 3

factors which affect faecal continenece

Answer 3

medications
natural age-related degeneration of nerve innervation
consistency of stool

Question 4

pelvic cavity

Answer 4

continuous with abdominal cavity above

lies between pelvic inlet and pelvic floor

contains pelvic organs and supporting tissues

Question 5

levator ani muscle = pelvic floor

Answer 5

forms the musculofascial inferior part of the pelvic cavity

Question 6

pelvic floor

Answer 6

openings in the pelvic floor permit the distal parts of alimentary, renal and reproductive tracts to pass from the pelvic cavity into the perineum

Question 7

distal GI tract within the pelvis and perineum

Answer 7

sigmoid colon becomes rectum anterior to S3 - recto-sigmoid junction

rectum becomes anal canal anterior to the tip of the coccyx just prior to passing through the levator ani muscle

anus is the distal end of the anal canal and is the orifice through which faeces pass

rectum is in the pelvis and the anal canal and anus are in the perineum

Question 8

rectum

Answer 8

rectal ampulla lies immediately superior to the elevator ani muscle

walls can relax to accommodate faecal material

sphincters required

Question 9

MALE

between bladder and rectum

Answer 9

rectovesical pouch

Question 10

FEMALES

between bladder and uterus

Answer 10

vesicouterine pouch

Question 11

FEMALES

between uterus and rectum

Answer 11

rectouterine pouch of Douglas

Question 12

levator ani muscle

Answer 12

made up of a number of smaller muscles - pubococcygeus, puborectalis, iliococcygeus

skeletal muscle

forms floor of pelvis and roof of perineum

tonically contracted most of the time

reflexively contracts further during increase in intra-abdominal pressure (coughing, sneezing)

supplies by branch of the sacral plexus and pudendal (S2, 3, 4)

Question 13

puborectalis

Answer 13

maintaining faecal continence

contraction - decreases anorectal angle
acts like a sphincter

skeletal muscle (voluntary)

Question 14

anal sphincters

Answer 14

internal - smooth muscle
superior 2/3 of anal canal
stimulated by sympathetic nerves 
inhibited by parasympathetic nerves
contracted all the time

external - skeletal
inferior 2/3 od anal canal
stimulated by pudendal nerve
voluntarily contracted

Question 15

nerve supply in pelvis

Answer 15

body cavity

sympathetic, parasympathetic and visceral afferent

Question 16

nerve supply in perineum

Answer 16

body wall

somatic motor and somatic sensory

Question 17

nerve supply to rectum/anal canal

Answer 17

sympathetic fibres = T12-L2

visceral afferents = S2-S4
parasympathetic fibres = S2-S4
somatic motor = S2,3,4

Question 18

pudendal nerve

Answer 18

branch of sacral plexus

S2,3,4 anterior rami

supplies external anal sphincter

sciatic foramen

Question 19

damage to pudendal nerve or sphincter

LABOUR

Answer 19

branches of the pudendal nerve could be stretched
fibres within the puborectalis or external anal sphincter muscle could be torn

results in weakened muscle and may lead to faecal incontinence

Question 20

anal canal - pectinate line

Answer 20

marks the junction between the part of the embryo which formed the GI tract and the part that formed the skin

superior = visceral
inferior = parietal

Question 21

above pectinate line

Answer 21

autonomic
arterial supply = inferior mesenteric artery
venous drainage = hepatic portal system
lymphatic drainage = inferior mesenteric nodes

Question 22

below pectinate line

Answer 22

somatic and pudendal
arterial supply = interval ilicc artery
venous drainage = systemic venous system
lymphatic drainage = superficial inguinal nodes

Question 23

lymphatics of the pelvis

Answer 23

lymph vessels tend to lie alongside the arteries

interla iliac - inferior structures

external iliac - lower limbs and superior structure

common iliac - external and internal iliac nodes

common iliac nodes then drains to the lumbar nodes

Question 24

blood supply to rectum and anal canal

Answer 24

inferior mesenteric artery supplies the handgun organs (proximal half of the anal canal)

interal iliac artery
degree of anastomoses between these vessels

Question 25

venous drainage from rectum and anal canal

Answer 25

inferior mesenteric vein drains the hind gut organs

internal iliac vein drains below pectinate line

Question 26

rectal varices

Answer 26

form in relation to portal hypertension

dilation of collateral veins between portal and systemic venous systems

Question 27

haemorrhoids

Answer 27

prolapses pf the rectal venous plexuses

development is not related to portal hypertension

raised pressure - chronic constipation, straining, pregnancy

Question 28

ischioanal fossae

Answer 28

lie on each side of the anal canal

filled with fat and loose connective tissue

communicate with each other posteriorly

infection - ischioanal abscess

Question 29

clinical examination

Answer 29

PR exam
assess the anal tone
palpate prostate anteriorly
palpate cervix

proctoscopy - inferior of rectum

sigmoidoscopy - inferior os sigmoid colo

colonoscopy - inferior of the colon