defecation Flashcards
What systems are involved in defecation?
GIT
nervous
muscoskeletal
What does the right colon do?
reservoir that mixes and stores contents
What does the left colon do?
conduit - transmits water and fluid
What does the colon do?
- delays passage to allow for water absorption
- mixing of contents with mucosa
- storing before defecation
- propel towards rectum
- begin urge
what 2 sphincters control defecation?
internal anal sphincter
external anal sphincter
internal anal sphincter (muscles and voluntary/involuntary)
smooth muscle cells
involuntary control
external anal sphincter
striated muscle cells
voluntary control
What nerve controls voluntary motor control of fecal/urinary continence?
pudendal nerve
Where does pudendal nerve come from?
sacral spinal cord
S2 - S4
Where does pudendal nerve go to?
anus
vagina
bladder
What nerve regulates emptying of bladder and opening/closing of urethral sphincter?
pelvic nerve
Where does the pelvic nerve go to?
rectum
bladder
What nerve for proprioception and functioning of urethral/anal sphincters?
hypogastric nerve
What dos the pudendal nerve do?
voluntary motor control of fecal/urinary contenince
What dos the hypogastric nerve do?
proprioception and proper functioning of urethral and anal sphincters
What dos the pelvic nerve do?
regulates emptying of bladder
open/closes urethral sphincter
When is the pre-defecatory phase?
1hr before defecation
What happens in pre-defecatory phase?
colon experiences an increase in peristaltic waves
mass movement from intestine into rectum
Recto-anal inhibitory reflex?
determines whether contents are gaseous/liquid/solid
What does contact of the stool with receptors in upper anal canal affect?
relaxation of the inner anal sphincter
What contracts during excretion?
abdominal muscles
What relaxes during excretion? (2)
external anal sphincter
puborectalis muscle
What causes steatorrhea?
lack of adequate amounts of pancreatic enzymes
lack of bile acids
intestinal malabsorption
When is steatorrhea common?
after gallbladder removal
Symptoms of clostridioides infection?
watery diarrhoea
fever
nausea
abdominal pain
