Autonomics Extra

Question 1

Alpha-1 Receptors

Answer 1

1. Contract radial muscles–> dilate the pupils
2. Vasoconstrict–> increase BP

Question 2

B2 receptors

Answer 2

1. Releax ciliary M–> flattens lens
2. Bronchodilation
3. Relaxation of smooth muscle

Question 3

B1 receptors

Answer 3

Located in the SA and AV node

Increase HR

Increase SV

Question 4

Hear a gunshot.

What is our ANS response and what part of our body drives this response?

Answer 4

Sympathetics

Our autonomic NS is driven by our brain.

Question 5

What responses does our sympathetic NS elicit?

Answer 5

1. Increase in HR: thus, we want to increase oxygen to the tissue that is important
2. Increase O2 to the lungs
3. Dilate our pupils and flatten our lens
4. Increase glucose for skeletal muscle to use and increase FFA for our other muscles
5. Decrease digestion

Question 6

When our sympathetic NS is activated, our HR increases. Why?

And what is the mechanism that this occurs?

Answer 6

HR increases so that we can deliver O2 and blood to the tissues.

1. Increase the frequency of the SA and AV node via B1 receptors
   - Increase firing
   - Increase phase 4 via Na+ funny channels
   - Increase HR
2. Increase the activity of our ventricule myocytes via B1 receptors
   - Increase Ca2+ influx (phase 2)
   - Increase contraction
   - Increase SV

THESE TWO PROCESSES TOGETHER WILL INCREASE CARDIAC OUTPUT

Question 7

During sympathetic response, we want to increase BF to the skeletal muscle. How do we do this?

Answer 7

Vasodilation

• Sympathetic activation of B2 receptors on the smooth muscle
• Relaxation
• Dilation
• Increase blood flow

Question 8

During sympathetic response, we want to maintain blood flow to the brain, heart and lungs. How do we do this?

Answer 8

They get little to no sympathetic innervation.

Question 9

During sympathetic response, we want to decrease BF to our gut, kidneys and skin. How do we do this?

Answer 9

Vasoconstrict

Activate alpha 1 receptors, which will redirect blood to our skeletal muscle

Question 10

How does sympathetic activity affect our eyes?

Answer 10

1. Pupils dilate via alpha-1 receptors (radial muscles contract)
2. Lens flatten via B2 receptor (ciliary muscle relaxes)

Question 11

During a sympathetic response, we need to increase nutrients (glucose) to increase aTP. How do we do this?

Answer 11

1. Stimulate A receptors on the pancrease, which will decrease insulin
2. Stimulate A/B receptors on the liver and skeletal muscle, which will increase glycogenolysis
3. Stimulate B receptors in adipose tissue to increase lipolysis.

Question 12

How does our sympathetic NS affect our gut?

Answer 12

1. Decrease motility by activating B2 receptors
2. Decrease secretion of enzymes by activating A receptors (constricting)
3. Increase sphincters by A1 receptors