Neurotransmitters and neuromodulators

Question 1

Acetylcholine (ACh)

Answer 1

• Source: Cholinergic neurons
• Actions:
  Contraction of smooth muscle in wall
  Relaxation of sphincters
  ↑ Salivary secretion
  ↑ Gastric secretion
  ↑ Pancreatic secretion

Question 2

Norepinephrine (NE)

Answer 2

• Source: Adrenergic neurons
• Actions
  Relaxation of smooth muscle in wall
  Contraction of sprinters
  ↑ Salivary secretion

Question 3

Vasoactive Intestinal Peptide (VIP)

Answer 3

• Source: Neurons of mucosa and smooth muscle
• Action
  Relaxation of smooth muscle
  ↑ Increase secretion
  ↑ Pancreatic secretion

Question 4

Gastrin- Releasing Peptide (GRP) // Bombesin

Answer 4

• Source: Neurons of gastric mucosa
• Action
  ↑ Gastrin secretion

Question 5

Enkephalins (opiates)

Answer 5

• Source: Neurons of mucosa and smooth muscle
• Action
  Contraction of smooth muscle
  ↓ Intestinal secretion

Question 6

Neuropeptide Y

Answer 6

• Source: Neurons of mucosa and smooth muscle
• Action
  Relaxation of smooth muscle
  ↓ Intestinal secretion

Question 7

Substance P

Answer 7

• Source: Co-secreted with ACh
• Action
  Contraction of smooth muscle
  ↑ Salivary secretion