Autonomic Nervous System

Question 1

What is the main function of the sympathetic nervous system?

Answer 1

It prepares the body for “fight-or-flight” by increasing heart rate, blood pressure, and respiratory rate, and decreasing digestive activity.

Question 2

What is the main function of the parasympathetic nervous system?

Answer 2

It promotes “rest-and-digest” functions by conserving energy, slowing heart rate, and increasing digestive activity.

Question 3

How are sympathetic pathways anatomically structured?

Answer 3

Short preganglionic neurons from the thoracic/lumbar spinal cord; ganglia near the spinal cord; long postganglionic neurons.

Question 4

How are parasympathetic pathways structured?

Answer 4

Long preganglionic neurons from the brainstem/sacral cord; ganglia near or within target organs; short postganglionic neurons.

Question 5

What neurotransmitters and receptors are involved in sympathetic pathways?

Answer 5

Preganglionic: ACh to nicotinic receptors.
Postganglionic: NE to adrenergic receptors (except ACh to sweat glands).

Question 6

What neurotransmitters and receptors are used in parasympathetic pathways?

Answer 6

Preganglionic: ACh to nicotinic receptors.
Postganglionic: ACh to muscarinic receptors.

Question 7

What are chromaffin cells?

Answer 7

Modified sympathetic postganglionic neurons in the adrenal medulla that release epinephrine and norepinephrine into the blood.

Question 8

What parts of the brain control autonomic function?

Answer 8

The hypothalamus and brainstem (medulla, pons) integrate sensory input and coordinate autonomic responses.