Autonomic Nervous System

Question 1

What is similar to a somatic reflex and autonomics?

Answer 1

Both use a two neuron system

Question 2

What are the general functions of the sympathetic nervous system

Answer 2

Dilate pupils Inhibit saliva production Dilate bronchi Increase HR Inhibit digestive organs Inhibit pancreas and gallbladder Stimulates adrenal medulla to release EPi and NE Relaxes bladder Liver will release more glucose into bloodstream and will release more free fatty acids

Question 3

What are the general functions and effects of the parasympathetic nervous system?

Answer 3

Constricts pupils Reduces heart rate Constricts bronchi Stimulates digestive organs Stimulate pancreas and gallbladder Constricts bladder Storage of glucose in liver increased Increased ability to store FFAs in adipose tissue

Question 4

What is the preganglionic NTX and receptor of the parasympathetic nervous system?

Answer 4

ACh nAChR

Question 5

What is the postganglionic NTX and receptor of the parasympathetic NS?

Answer 5

ACh mAChr (activates second messenger system-Gi or Gq)

Question 6

• What are some unique features about post-ganglionic parasympathetic neurons?

Answer 6

• Varicosities along length of axon
• Synaptic cleft is larger and more open to interstitial fluid
• Receptors for NTX are distributed over much broader area
• So we can detect these NTX in the blood and the receptors can be activated from far away depending on how far the NTX has traveled

Question 7

What is the NTX for pre-ganglionic sympathetic fibers?

What is the receptor?

Answer 7

• ACh
• nAChR

Question 8

• What is the NTX for post-ganglionic sympathetic neurons?
• What is the receptor?

Answer 8

• NE
• Alpha or beta adrenergic receptors (which are metabotropic and activate second messenger system)
• Side note: different receptor subtypes allow NE to have different effects in different tissues