alimentary controls Flashcards
what type of nerves control the alimentary system?
somatic -sensory -motor autonomic -sympathetic -parasympathetic
what GIT hormones control the alimentary system?
CCK
gastrin
gastric inhibitory peptide
secretin
describe the extent of controls
stomach -> SI =hormonal oral cavity =somatic middle organs =autonomic anal canal =somatic
how does secretion occur in the mouth and pharynx?
saliva
how does motility occur in the mouth & pharynx?
chewing & swallowing
how does saliva secretion occur?
chemical -taste and small mechanica -chewing -loading PDL
which describe saliva secretion stimulus in terms of size of effect
chemical
mechanical
olfactory
visual
how does chewing occur?
jaw, facial, tongue muscles
skeletal- somatic nerve control
voluntary- CN V, VII, XII
how does swallowing occur?
jaw, tongue, pharyngeal muscles
skeletal
voluntary CN V, IX, X, XII
describe control occur in the oesophagus?
mix of skeletal & SM
control CNX
what is secreted in the stomach?
gastric juice
describe motility in the stomach
filing, relaxation
mixing
propulsive: peristalsis
emptying
describe the cephalic phase
mechanical-chewing
chemical-taste, smell
psychic- visual, emotional
nerves -long reflex
describe the gastric phase
mechanical-distension
chemical-food in stomach
nerves-long & short reflex
hormone-gastrin
describe the intestinal phase
mechanical-distension chemical-acid, protein in duodenum nerves-long & short reflexes hormones-GIP, secretin slow gastric emptying
what is secreted in the SI?
intestinal juice-from pancres
describe motility in the SI
mixing
villus movements
segmentation contractions
peristalsis
describe nerve control of the SI
local nerves in response to intra-luminal stimuli
describe bicarbonate (hormonal) in the pancreas
intestinal phase
secretin
-released from duodenum in response to acid
-stimulates secretion of bicarbonate-rich pancreatic juice
CCK & VIP
-weak stimulatory effect on bicarb secretion
describe enzyme (hormonal) in the pancreas
intestinal phase
CCK
-released from duodenum in response to fat & protein
-stimulates secretion of enzyme rich pancreatic juice
gastrin and GIP
-weak stimulatory effect on enzyme secretions
describe the secretion of bile
cephalic phase -vagus nerve -relaxation of oddi(vagus) intestinal phaseCCK -released from duodenum in response to fat & protein -stimulates contraction of gall bladder -relaxation of sphincter of oddi secretin -weaker effect
what is secreted in the LI and rectum?
mucus
some water & electrolytes
describe motility in the LI
mixing
mass movements
defaecation
describe neuronal control in the large bowel
local reflexes triggered by food entering the stomach
-increased motility in intestines
gastro-ileal reflex
-gastric activity increased motility on ileum
gastro-colic reflex
-gastric activity increased motility on colon
