Functional Aspects of the Autonomic Nervous System

Question 1

What is the major pathway for information transmission from the CNS to the involuntary effector tissues (smooth muscle, cardiac muscle, and exocrine glands)?

Answer 1

The motor efferent portion of the ANS

Question 2

What is the meaning of Adrenergic?

Answer 2

A nerve ending that releases norepi as the primary transmitter

Question 3

What is meant by adrenergic receptor?

Answer 3

A receptor that binds and is activated by one of the catecholamine transmitters or hormones such as; epi, norepi, dopamine and related drugs

Question 4

What is meant by cholinergic?

Answer 4

Nerve ending that releases acetylcholine; also a synapse where the primary transmitter is acetylcholine

Question 5

What is meant by homeostatic reflex?

Answer 5

A compensatory mechanism for maintaining a body function at a predetermined level

Question 6

What is the primary transmitter in all autonomic ganglia and at the synapses between parasympathetic postganglionc neurons and their effector cells

Answer 6

Acetylcholine

Question 7

What is the rate limiting step in the synthesis and storage of Acetylcholine?

Answer 7

The transport of into the nerve terminal

Question 8

What drug can inhibit the transport of Acetylcholine into its nerve terminals after synthesis?

Answer 8

Hemicholinium

Question 9

What is the transporter responsible for transporting acetylcholine into its vesicles for storage?

Answer 9

Vesicle associated transporter VAT

Question 10

What drug inhibits VAT?

Answer 10

Vesamicol

Question 11

What ion mediates the release of acetylcholine from its vesicles in nerve endings?

Answer 11

Calcium entry through channels and triggering of an interaction between SNARE proteins and t-SNARE

Question 12

How does Botulinum toxin work?

Answer 12

Enzymatically alters synapto-brevin or one of the other docking or fusion proteins to prevent the release process of acetylcholine

Question 13

How is the Acetylcholine action terminated?

Answer 13

ACh is metabolized to acetate and choline by Acetylcholinesterase in synaptic cleft

Question 14

What is the primary transmitter at sympathetic postganglionic neuron effector cell synapses in most tissues?

Answer 14

Norepi

Question 15

What function does serve in Renal blood vessels?

Answer 15

Vasodilator transmitter

Question 16

What is the rate limiting step and enzyme in the synthesis of Norepi and Dopamine?

Answer 16

The hydroxylation of Tyrosine to DOPA by Tyrosine Hydroxylase

Question 17

How can tyrosine hydroxylase be inhibited?

Answer 17

By Metyrosine

Question 18

What molecule transports Norepi and Dopamine into their vesicles?

Answer 18

VMAT

Question 19

What is (MOA) Monoamine Oxidase?

Answer 19

A molecule which is present on mitochondria in the adrenergic nerve ending that inactivates a portion of the dopamine and norepi in the cytoplasm

Question 20

What effect does MOA inhibitors have?

Answer 20

Inhipits the breakdown of Norepi and Dopamine and othe monoamines in nerve endings

Question 21

What drug inhibits VMAT?

Answer 21

Reserpine

Question 22

What mechanism is responsible for the release of Norepi and Dopamine?

Answer 22

Same as ACh, calcium dependent

Question 23

What mechanisms are responsible for the termination of action of Norepi and Dopamine.

Answer 23

Diffusion and reuptake (especially uptake 1) by transporters NET and DAT

Question 24

What does Guanethidine do?

Answer 24

Blocks norepinephrine release blocking sympathetic but not parasypathetic functions

Question 25

What are Muscarine receptors?

Answer 25

These receptors respond to Muscarine as well as acetylcholine, the effect of these receptors resemble those of postganglionic parasympathetic nerve stimulation.

Question 26

Where are muscarinic receptors mostly located?

Answer 26

Primarily on autonomic effector cells incuding heart vascular endothelium smooth muscle and presynaptic nerve terminals

Question 27

What do all muscarinic receptors have in common?

Answer 27

Are G-coupled receptors

Question 28

What are the nicotinic receptors?

Answer 28

These receptors are located on Na-K ion channels and respond to acetylcholine and nicotine but not Muscarine by opening the channel

Question 29

Where are the Nicotinic receptors located?

Answer 29

In ganglia and in Skeletal muscle

Question 30

What are the Adrenoceptors?

Answer 30

1. Alpha | 2. Beta

Question 31

Where are Alpha receptors located?

Answer 31

On vascular smooth muscle, presynaptic nerve terminals, blood platelets, fat cells and neurons in the brain

Question 32

Where are Beta receptors located?

Answer 32

Mostly on smooth muscle, cardiac muscle some presynaptic nerve terminals and lipocytes

Question 33

What do all the subtypes of Beta receptors have in common?

Answer 33

All us the same G-coupling protein

Question 34

Where are Dopamine receptors most found/important?

Answer 34

Renal and Splanchnic vessels and the Brain

Question 35

Which is the most important subtype of Dopamine receptors?

Answer 35

D1

Question 36

What is the purpose of the release of ATP and substance P with ACh?

Answer 36

Modulation

Question 37

What is an presynaptic AUTORECEPTOR?

Answer 37

is a receptor for the Ligand that is being released from the presynaptic nerve ending at a cholinergic synapse it would be a Muscarinic receptor and it essentially turns off action

Question 38

What is a presynaptic Heteroreceptor?

Answer 38

Regulatory receptor that responds to substance other than the transmitter itself

Question 39

Drugs which are not impacted by Acetylcholinesterase inhibitor

Answer 39

Carbachol Chloride | Bethanecol chloride

Question 40

How do Cocaine, and Tricyclic antidepressants work?

Answer 40

Inhibit uptake of Norepi from synaptic cleft by blocking NET

Question 41

How does Bretylium guanethidine work?

Answer 41

Inhibiting fusion of transmitter containing vesicles with the end plate by blocking VAMPs in Adrenergic fibres

Question 42

Where are Beta-2 Adrenergic receptors mostly found?

Answer 42

Lung | Vasculature of Skeletal Muscle

Question 43

What is the specificity of the transmitter Epi?

Answer 43

A-a=A-2;B-1=B-2

Question 44

Which drug causes a widening of the pulse pressure?

Answer 44

Epinephrine

Question 45

Why does Pulse pressure widen when Epi is given?

Answer 45

Due to stimulation of Beta-2 which causes vasodilation and pressure is falling

Question 46

What is the difference in Calcium dependency for Myocyte contraction vs Smooth muscle of vasculature?

Answer 46

In Cardiac cells its the release of Ca2+ from SR where as in smooth muscle its the influx of Calcium from outside the ell that triggers the action

Question 47

What is the effect of activation of the B-2 receptors in Bronchio Smooth muscle?

Answer 47

Relaxation of the smooth muscle

Question 48

What is Tachyphylaxis?

Answer 48

Loss of activity of a drug

Question 49

Which receptors are stimulated in response to Hypoglycemia?

Answer 49

Alpha-1 and Beta-2

Question 50

In which type Diabetes would you expect non-selective Beta Blockers to delay recovery from hypoglycemia?

Answer 50

Type -1

Question 51

Is there Cholinergic innervation of the Blood vessels?

Answer 51

No

Question 52

What is the effect of Mucarinic agents on the vasculature then?

Answer 52

Promote release of NO which causes Vasodilation