Nervous System & Drugs

Question 1

What are the brain and spinal cord nourished by and what is it?

Answer 1

By the circulation of cerebrospinal fluid which is a clear watery fluid that contains many of the constituents of blood but lacking rbcs

Question 2

Sensory nerves another name?

Answer 2

Afferent (towards the spinal cord)

Question 3

Motor nerves another name?

Answer 3

Efferent (away from the spinal cord)

Question 4

Somatic nervous system concerned with:

Answer 4

Mostly voluntary: to convey sensation from skeletal or voluntary muscles, skin, sense organs (Afferent)

to initiate voluntary skeletal muscle contraction (Efferent)

Question 5

Visceral nervous system (Afferent) concerned with:

Answer 5

Involuntary actions, conveys sensory information from visceral organs e.g. Heart, lungs, kidneys/stomach ache

Initiates muscle contraction by utilising the autonomic nervous system

Question 6

Autonomic nervous system (Efferent) concerned with:

Answer 6

Exciting (contracting) or inhibiting (relaxing) smooth muscle (not under voluntary control e.g. Respiratory system, gastrointestinal tract)

Inhibit or excite cardiac muscle

Question 7

What are autonomic ganglia?

Answer 7

Clusters of neuronal cell bodies and their dendrites: a junction between autonomic nerves originating from the CNS and autonomic nerves inner sting their target organs in periphery

Question 8

Another word for cell body

Answer 8

Soma

Question 9

What are dendrites?

Answer 9

Short processes that convey electrical information towards the cell soma

Question 10

Another name for Schwann cell:

Answer 10

Neurolemmocyte

Question 11

What is necessary to enable the axon to conduct electrical activity?

Answer 11

The axon to be bathed by extracellular fluid at small, regularly repeating gaps (nodes of Ranvier) in myelin sheath

Question 12

What is myelin sheath made of?

Answer 12

A supporting glial cell, Schwann cell in periphery or oligodendrocyte in CNS

Question 13

What membrane bound protein is necessary for neuronal cell survival?

Answer 13

The Na+, K+ ATP-ase pump, which is an electrochemical pump. This pump requires ~ 40% of the energy requirements of the brain

Question 14

Why cannot charged ions permeate cell membrane unless in ion channels?

Answer 14

Membrane presents a very lipophilic environment. Ion channels form a hydrophilic pathway for ions

Question 15

What is saltatory conduction and why is it faster?

Answer 15

Occurs in myelinated neurones when the action potential jumps from one node to the next without having to depolarise the intervening axonal membrane which lies beneath the insulating myelin sheath. Therefore much faster

Question 16

What does a neurotransmitter bind to on the post synaptic neurone, muscle or gland?

Answer 16

Ligand-gated transmitter-gated receptors

Neurotransmitter-receptor protein interaction is quite specific.

Question 17

Why can communication between neurones only occur in one direction?

Answer 17

Because only the presynaptic nerve terminal contains the neurotransmitter

Question 18

Glutamate?

Answer 18

Major excitatory neurotransmitter in the brain

Question 19

GABA?

Answer 19

y- aminobutyric acid is the major inhibitory transmitter

Question 20

Acetylcholine?

Answer 20

In periphery: major transmitter at the skeletal (voluntary) neuromuscular junction and in the parasympathetic limb of autonomic nervous system

Question 21

Noradrenaline?

Answer 21

Transmitter in the sympathetic nervous system