Neurological Pharmacology

Question 1

Two basic steps by which neurons influence the behaviour of postsynaptic cells

Answer 1

Axonal conduction - Action potenital

Synaptic transmission – information is carried across the gap b/w the neuron and the postsynaptic cell

Question 2

Drugs that alter axonal conduction are not selective T/F

Answer 2

True, axons are all alike. Ex. local Anesthetics (decrease speed of action potential).They suppress transmission in any nerve they reach, thus the use of local anesthetics are very limited

Question 3

Feedback loops - Example / Where are they located?

Answer 3

Carotid Artery

Question 4

A patient is required to have a procedure that requires Axon conduction blockade, what medication will be used?

Answer 4

A local anesthetic will alter axonal conduction

Question 5

How do drugs alter receptor activity at the synapses? (5 steps involved)

Answer 5

Transmitter Synthesis, Transmitter storage, transmitter release, receptor binding, termination of transmission.

Question 6

What are the three primary neurotransmitters in the PNS

Answer 6

Acetylcholine, Norepinephrine and Epinephrine

Question 7

How is acetylcholine released?

Answer 7

All pre-ganglionic neurons of the PNS
All pre-ganglionic neurons of the SNS
All post-ganglionic neurons of the PNS
All motor neurons of the SNS 
Most post-ganglionic neurons of the SNS innervates sweats glands.

Question 8

How is Norepinephrine released?

Answer 8

All post-ganglionic neurons of the SNS - except those that innervates sweat glands

Question 9

How is Epinephrine released?

Answer 9

The Adrenal Medulla

Question 10

What are the two receptor types in the PNS

Answer 10

Cholinergic Receptors - mediate responses of acetylcholine

Adrenergic receptors - mediate responses to Epinephrine
and Norepinephrine

Question 11

What are three cholinergic subtypes

Answer 11

Nicotinic N
Nicotinic M
Muscarinic

**All respond to Acetylcholine but have different effects from one another **

Question 12

Nicotinic N

Answer 12

Activation of this receptor causes ganglionic transmission at all ganglia of the SNS and PNS. It also promotes release of epinephrine from the adrenal medulla

Question 13

Muscarinic

Ex.

Answer 13

Activation of these receptors cause;
Increased glandular secretions
Contraction of smooth muscle in the bronchi and GI tract.

Organophosphate

Question 14

What are Adrenergic subtypes? (four types)

Answer 14

A1, A2, B1, B2

Question 15

A1 - location, causes, effects.

Answer 15

Located in the eyes, blood vessels, male sex organs, prostate capsule and bladder

Causes: Pupil dilation, vasoconstriction, ejaculation

Question 16

A2 - location, causes, effects.

Answer 16

Located on nerve terminals and not organs innervated by the autonomic nervous system.

Norepinephrine binds to A2 receptors and this causes a further suppression of norepinephrine release.

This can help reduce Norepinephrine release when too much transmitter has accumulated in the synaptic gap.

Question 17

B1 - location, causes, effects.

Answer 17

Located in the heart and kidneys

Causes the release of Renin into the blood, this promotes synthesis of angiotensin (vasoconstriction)

Increase dromotropic, chronotropic and inotropic effects in the heart

Question 18

B2 - location, causes, effects.

Answer 18

Located in the lungs, uterus, skeletal muscle and liver

Causes; bronchial dilation, uterine smooth muscle relaxation, vasodilation in arterioles

Question 19

What are two basic categories of receptors?

Answer 19

Cholinergic receptors - Mediated by acetylcholine

Adrenergic receptors - Mediated by Epi / Norepi

Question 20

Nuerotransmitter Life Cycles - Many drugs produce their effects by interfering with what three life cycles?

Answer 20

Acetylcholine, Epinephrine and Norepinephrine

Question 21

Life Cycle - Epinephrine

Answer 21

Synthesized within chromatin cells of the adrenal medulla

Question 22

Life Cycle - Norepinephrine

Answer 22

Made from a series of precursors 
Stored in vesicles for release
Released into the synapse 
Interacts with A1, A2, B1 receptors 
Undergoes re-uptake back into the nerve terminals 

Once it is back in the nerve terminal it is reused or degraded by enzyme Monoamine Oxidase (MAO)

Question 23

Neuropharmacology

Answer 23

The study of drugs that alter the processes controlled by the nervous system.

Question 24

Neuropharmacology - two categories

Answer 24

Drugs that alter the Central Nervous System and the Peripheral Nervous System

Question 25

Neuropharmacological drugs alter what process

Answer 25

CO, Skeletal muscle contraction, vascular tone, respiration, GI function, Uterine motility, Glandular secretion, Ideation, mood, and perception of pain

Question 26

Where are neurotransmitter molecules released from and where do they bind

Answer 26

Axon Terminals, and they bind on the postsynaptic cells

Question 27

What happens if the postsynaptic cell is another neuron?

Answer 27

It increases its firing rate

Question 28

What happens if the postsyncaptic cell is a muscle? or A granular

Answer 28

It will either contract or relax. | Granular with increase or decrease secretions

Question 29

Do most neuro drugs alter synaptic transmissions or axonal conduction and which ones are more selective?

Answer 29

Most drugs alter synaptic transmission, only a few drugs alter axonal conduction. Drugs that alter synaptic transmission can produce effects that are much more selective than those altering axonal conduction.

Question 30

Step 1: Transmitter synthesis

Answer 30

Transmitters must be present in the nerve terminals for synaptic transmission to take place.

Question 31

Step 2: Transmitter storage

Answer 31

Once the transmitter is synthesized it is stored until the time of its release Transmitter storage takes place within vesicles (tiny packets in the axon terminal) Each nerve terminal contains many of the vesicles

Question 32

Step 3 Transmitter release

Answer 32

``` Release of the transmitter is triggered by arrival of an action potential (through the axon) at the terminal. The vesicles undergo fusion with the terminal membrane, and the contents are released into the synaptic gap. Each action potential causes only a small fraction of vesicles to discharge their contents ```

Question 33

Step 4 Receptor Binding

Answer 33

Following release, transmitter molecules diffuse across the synaptic gap and undergo reversible binding to receptors on the post synaptic cell. Binding to receptors causes a cascade of events that result in altered behavior of the post synaptic cell

Question 34

Step 5 Termination of Transmission

Answer 34

Transmission is terminated by dissociation of the transmitter from its receptors. Transmitter molecules can then either undergo: Reuptake (pumped) into axon terminals from where they were released. Enzymatic degradation in the synapse. Diffusion away from the synaptic gap

Question 35

PNS physiology what two systems are included?

Answer 35

Includes: Autonomic nervous system (ANS): Parasympathetic – rest and digest Sympathetic – fight or flight Somatic Motor System – voluntary nervous system (skeletal muscle)

Question 36

What are Three principal functions of the ANS

Answer 36

* Regulate the heart * Regulate the secretory glands (salivary, gastric, sweat, and bronchial) * Regulate the smooth muscles (bronchi, blood vessels, urogenital system, and gastrointestinal tract).

Question 37

What are the 7 regulatory functions of PNS?

Answer 37

* Slowing the heart rate * Increasing the gastric secretions * Emptying the bladder * Emptying the bowel * Focusing the eye for near vision * Constricting the pupil * Contracting the bronchial smooth muscle