2 - ANS review

Question 1

Describe the general CNS organization.

What areas of the CNS do the sympathetic and parasympathetic systems connect to?

Answer 1

Question 2

Review the arrangement of spinarl cord to sympathetic ganglion to tissue, and related neurotransmitters.

Answer 2

Voluntary motor nerves connect tissue directly to target tissue, but all sympathetic have an intermediate pre-synaptic neuron that runs from the spinal cord to the sympathetic ganglia. Then a post-synaptic neuron runs from the sympathetic ganglia out to the target tissue.

Note: At the junction of pre-synaptic and post-synaptic junction is ACh.

Note: N (nicotinic) cholinergic receptors are at the junction on the post-synpatic side.

Note: Norepinephrine is functioning as a neuotransmitter and epinepherine is functioning more as a hormone.

Question 3

What does dual innervation refer to in the ANS?

Answer 3

All of our major systems have dual innervation by sympathetic and parasympathetic systems, allowing us to counterbalance.

Question 4

What are the neurotransmitters of:

Prasympathetic NS

Sympathetic NS

Answer 4

Question 5

What are the neuro receptors of the PSNS and SNS?

Answer 5

Question 6

Where do the nicotinic receptors tend to be located?

Where do the muscarinic receptors tend to be located?

Answer 6

Don’t memorize. Just note:

Nicotinic receptors tend to be on the neuromuscular junctions (where nerve meets muscle), in the autonomic ganglia (the sympathetic chain), CNS, and Adrenal medulla.

Muscarinic receptors tend to be everwhere else.

Question 7

What is the effect of ACh on a nicotinic receptor (always)?

Answer 7

ACh will always be stimulatory to a nicotinic receptor.

Question 8

What receptor types bind ACh?

Where are nicotinic receptors found?

What is the effect of ACh on nicotinic receptors?

Where are muscarinic receptors found?

What is the effect of ACh on muscarinic receptors?

Answer 8

Cholinergic receptors: Nicotinic and muscarinic.

Question 9

Where are the following adrenergic receptors found? What do they do?

• α-1
• α-2
• β-1
• β-2
• Dopaminergic

Answer 9

• α-1: These are on the vascular wall and genitourinary smooth muscles. Activating them causes contraction of smooth muscle.
• α-2: Found in the SNS vacular connections and CNS. WHen activated it inhibits NE release and inhibits SNS activation. As a result, vascular smooth muscles relax. α-1 and α-2 work against eachother in this way.
• β-1: effects heart rate and how quickly the cardiac impulse travels across the heart. When β-1 is stimulated you get chronotropy (increase heart rate) and inotropy (increased force of heart contraction)
• β-2: Found in blood vessels and bronchioles, causes vasodilation and bronchodilation
• Dopaminergic: Found on vascular smooth muscle in the gut and renal circulation. When stimulated it causes increased blood flow to mesenteric muscles and kidneys.

Question 10

Review functions of hte PSNS

Answer 10

miosis = pupil constriction

vagus nerve (cranial nerve X) allows decrease of HR, bronchoconstriction, peristalsis/secretion, and bile release

Question 11

Review the structure of the SNS and its effects.

What are the major neurotransmitters?

Answer 11

Key neurotransmitters are NE, with E operating as a hormone.

Eyes dilate (mydriasis)

Heart beats faster/harder

Blood vessels: BP increases, perfusion increases to heart and brain

Glucose: liver breaks down glycogen for glucose

Bladder: stops

GI: slow motility

Question 12

How do the PSNS and SNS counterbalance eachother? Describe the ennervations and key neurotransmitters.

Answer 12