Lecture 12: Autonomics (CIS)

Question 1

As you are walking, you hear a gunshot and your sympathetic system activates. Describe what is going in with the SA and AV nodes.

Answer 1

Activation of β1 adrenergic receptors from T1-T5 of spinal cord

• heart rate is increasing
• increase in depolarization

Question 2

As you are walking, you hear a gunshot and your sympathetic system activates. Describe what is going in with the ventricular myocytes.

Answer 2

Activation of β1 adrenergic receptors from T1-T5 of spinal cord

• increase in contractility, stroke volume, and cardiac output
• increase of calcium into myocytes

Question 3

As you are walking, you hear a gunshot and your sympathetic system activates. Describe what is going in with the vasculature of skeletal muscles.

Answer 3

Activation of β2 adrenergic receptors on vascular smooth muscle
-relaxation and dilation to allow increase of oxygen flow

Question 4

As you are walking, you hear a gunshot and your sympathetic system activates. Describe what is going in with the vasculature of abdominal organs, skin, kidney, and etc.

Answer 4

Activation of α1 adrenergic receptors on vascular smooth muscle

• promotes contraction and vasoconstriction
• redirects blood to skeletal muscle

Question 5

What happens to the lungs when there is parasympathetic activation?

Answer 5

Activation of muscarinic receptors

• Bronchoconstriction
• Increased mucus secretion

Question 6

What happens to the lungs when there is sympathetic activation?

Answer 6

Activation of β2 adrenergic receptors

-Bronchodilation (relax muscles)

Question 7

What happens to the juxtaglomerular apparatus when there is sympathetic activation?

Answer 7

Production of aldosterone –> reabsorption of sodium and water –> increase in blood volume