Gut free response

Question 1

Why would someone get diarrhea if they were frightened (dorsal freeze response?)

Answer 1

dorsal freeze response –> huge vagal stimulation –> release of serotonin from enterochromaffin cells in gut –> high intestinal mobility that churns food boluses to become liquid

Question 2

Why would someone get diarrhea if they had acute stress?

Answer 2

SNS activity acts on nearby T cells / dendrites to produce neurotransmitters (substance P) to increase mast cell activity –> mast cell degranulation –> mast cells release histamine that inflame the gut –> leaky and damaged epithelium –> excess liquid in stool

Question 3

How can pain in my gut affect HRV?

Answer 3

pain sensors in the myenteric plexus in the muscular region of the gut –> signal is passed to SNS spinal afferent nerves via ENS interneurons –> signal reaches spinal cord and passes pain bodies in dorsal root ganglia –> goes to heart which integrates pain into HRV and sends to brain