GIT hormones,their actions and sites of action.


  1. Secreted from I cells
  2. Acts on GB and pancreas
  3. Increase enzyme secretion
  4. Increase contraction

Gastro Intestinal Peptide(GIP)

  1. Secreted from K cells
  2. Acts on Pancreas
  3. Increase insulin
  4. Decrease fluid absorption


  1. Secreted from stomach
  2. Increase food intake
  3. Increase GH secretion


  1. Secreted from G cells
  2. Acts on parietal cells
  3. Increase H+ secretion

Gastrin Releasing Peptide(GRP)

  1. Secreted from vagal nerve end
  2. Acts on G cells
  3. Increase gastrin secretion


  1. Secreted from ileum and colon
  2. Acts on small and large intestines
  3. Increased fluid absorption


  1. Secreted from Mo cells
  2. Acts on upper GI
  3. Smooth muscle contraction


  1. Present all over intestine
  2. Acts  on intestinal smooth muscles
  3. Increase histamine release

Peptide YY

  1. Secreted from ileum and colon
  2. Acts on stomach and pancreas
  3. Decrease acid secretion and increase enzyme fluid


  1. From S cells
  2. Acts on pancreas and stomach
  3. Increase bicarbonate and fluid
  4. Decrease acid secretion from stomach


  1. Secreted from D cells
  2. Acts on stomach,pancreas,intestne,liver
  3. Decrease secretion and increase fluid

Substance -P

  1. From enteric neurons
  2. Acts on enteric neurons


  1. From ENS neurons
  2. Acts on SI and pancreas
  3. Increase secretion
  4. Decrease smooth muscle relaxation.
  1. thanks 🙂

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