Lesson B1 - PHYSIOLOGICAL AND PHARMACOLOGICAL ASPECTS OF THE CENTRAL AND PERIPHERAL NERVOUS SYSTEM Flashcards

1
Q

The nervous system can be divided into two main components

A

the central nervous system (the brain and spinal cord) and the peripheral nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

afferent or sensory nerve fibres which carry messages to the brain, and efferent nerve fibres which carry messages

A

from the brain and spinal cord to tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The efferent system is divided into motor nerves which innervate skeletal muscle, and

A

the autonomic nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The central nervous system (CNS) controls

A

all bodily functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

It consists of a central part, the

brain and spinal cord, linked to

A

a peripheral part, nerve fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The sensory nerve fibres carry

messages from tissues to the brain or spinal cord, and the motor nerve fibres carry messages

A

from the brain or spinal cord to the tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Three main parts of the brain

A
  1. Forebrain
  2. Midbrain
  3. Hindbrain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The forebrain: cerebral cortex =

A

This is the largest part of the brain which is very rich in nerve cells. It is composed of grey matter (outside) and white matter (inside); it is divided
into lobes or regions, each with specific functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The forebrain: Thalamus:

A

A relay centre; from here impulses are relayed to the cerebral cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The forebrain:Hypothalamus:

A

A very important area; consists of various specialized regions of nuclei
located near the base of the skull. The functions are to control the involuntary functions of
the body that are necessary for living, e.g. regulation of heart, blood pressure, body
temperature, and metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The forebrain: Pituitary

A

A small gland located at the base of the brain which secretes hormones that
control growth, behaviour and metabolism of the body through the action of these
hormones on peripheral tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The Midbrain

A

The midbrain is the area that links the forebrain with the hindbrain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The Hindbrain

A

Medulla (the bulb): This is the site of origin of many cranial nerves. It is where
regulation of respiration (breathing centre) and regulation of heart and blood pressure
occurs

Cerebellum: The cerebellum is a large, highly convoluted structure connected to the brain
stem by large fibre tracts. It is responsible for coordination and posture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The functional unit of the brain

A

is the neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

each nerve cell or neuron has three

parts:

A

The cell body or soma contains a nucleus and surrounding cytoplasm which is packed with
rough endoplasmic reticulum, a network of smooth endoplasmic reticulum, and abundant
vesicles which can be secreted.

The dendrites function as the receiving antennae for incoming information, are usually
short, and can have highly complex branching patterns.

The axon, a single fibre that extends from the cell body and ends at a synapse. The axon
carries signals away from the cell body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In order for the brain to function properly, the nerve cells (neurons)

A

must communicate with each

other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The junction between two neurons is called the

A

synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The synapse is commonly formed by contact of the

A

axon belonging to one neuron with a dendrite or

the cell body of another neuron.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The passage of a signal from one neuron to

another neuron is called

A

synaptic transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Synaptic transmission is usually

A

chemical in nature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Substances mediating synaptic transmission are

A

synaptic transmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In chemical transmission, the

release of a transmitter substance is required in order to

A

activate the other cell or pass on the

message.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The nerve impulse (electrical activity) passes down a nerve axon and releases

A

a chemical substance into the synaptic cleft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The postsynaptic membrane contains binding sites for the

chemical transmitter. These binding sites are called

A

receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The binding of the chemical
transmitter to the receptor usually provokes a change in the permeability of the membrane and
ions (calcium) move across the membrane, causing

A

a change in electrical activity of the

membrane and this electrical activity is passed along to the next cell

26
Q

. To

prevent the synapses from becoming non-functional, the chemical transmitter is

A

removed by one
of two major mechanisms: broken down by enzymes or taken back up into the presynaptic
structure.

27
Q

, after release into the synaptic cleft, the neurochemical transmitter or messenger
binds to specific molecules known as

A

receptors

28
Q

Receptors are

A

proteins synthesized in the rough
endoplasmic reticulum, transported to different parts of the cell and inserted into the cell
membrane of the cell body, dendrites and axons.

29
Q

each endogenous transmitter usually has its own

A

specific receptor

30
Q

When the transmitter binds to

the receptor, it

A

elicits a specific response.

31
Q

Drugs can either stimulate a receptor

A

called agonist, or inhibit action on a receptor (called antagonists)

32
Q

Acetylcholine:

A

. Cholinergic receptors have two broad classifications.
Those that are stimulated by nicotine are called nicotinic receptors. Nicotinic receptors are
found in all autonomic ganglia, at the neuromuscular junction, and in certain regions of the brain.
Muscarinic receptors are stimulated by the alkaloid, muscarine, and are found in a wide array of
the regions of the brain.

33
Q

Serotonin:

A

Serotonin and its receptors are found in the upper brain stem, with significant
amounts in the pons and medulla, hypothalamus, hippocampus, and cerebral cortex

34
Q

Dopaminergic pathways occur predominantly in three areas:

A

hypothalamus, basal ganglia and

brain stem, and midbrain

35
Q

Dopaminergic pathways are involved in control of some hormonal
systems (hypothalamus), motor coordination (basal ganglia), and motivation and

A

reward

36
Q

There are several subclasses of dopamine receptors. The two most important are D1 and D2. D1
receptors, when activated by dopamine, are excitatory and D2

A

receptors are inhibitory.

37
Q

Norepinephrine pathways originate in the brain stem and send projections to the cerebral cortex,
hypothalamus, limbic system, and the

A

cerebellum.

38
Q

There are a large number of receptor types for

norepinephrine. The two main classes are α and β. Activation of these receptors usually leads to

A

excitation of the cell, but one of the subclasses of these receptors, when activated, is inhibitory.

39
Q

Glutamate: Glutamate or glutamic acid is one of the more important

A

amino acid

neurotransmitters in the brain.

40
Q

Gamma-aminobutyric acid (GABA): GABA is the main inhibitory neurotransmitter in the

A

CNS

41
Q

GABAergic neurons and receptors are found in high concentrations in the cerebral cortex,
hippocampus and

A

cerebellum.

42
Q

A number of CNS depressants (e.g. barbiturates and

benzodiazepines) bind to the

A

GABA receptor.

43
Q

Opioid peptides: There are three main classes of opioid peptides:

A

enkephalins, endorphins, and

dynorphins.

44
Q

They have varying degrees of selectivity for one of the opioid receptors

A

mu (μ), delta (δ) or kappa (κ).

45
Q

The μ opioid receptor subtype is most abundant in the cerebral cortex, hypothalamus, brain stem,
and part of the spinal cord. This distribution is consistent with their involvement

A

in pain regulation.

46
Q

The δ opioid receptor is concentrated in the olfactory system and various limbic
structures where they play an important role in

A

olfaction, motor integration (coordination),

reward, and cognitive (thinking) functions

47
Q

The κ receptors are abundant in the caudate-putamen and hypothalamic sites and are involved in regulation of food intake, water balance, pain
perception, and

A

control of the endocrine system.

48
Q

The efferent component of the peripheral nervous system consists of the motor nerves and

A

the autonomic nervous system.

49
Q

The autonomic nervous system (ANS) is involved in maintaining a

A

stable internal environment

50
Q

the autonomic nervous

system is often called the

A

involuntary nervous system

51
Q

The Autonomic Nervous system has two distinct parts.

A
  1. Sympathetic (system)

2. Parasympathetic (system)

52
Q

The parasympathetic and sympathetic systems normally act in a

A

balanced and opposite fashion

53
Q

Parasympathetic system: General stimulation of this system promotes or increases

A

the vegetative functions of the body.

54
Q

At rest, the parasympathetic type of activity is the predominant
activity. The sympathetic activity is largely

A

inhibited.

55
Q

Sympathetic system: General stimulation of this system results in the mobilization of resources
to prepare the body to

A

meet emergencies.

56
Q

The mass sympathetic discharge results in increased

activity of many functions of the body, including

A

increased heart rate, blood pressure, blood

supply to the tissues, rate of cell metabolism, and blood glucose

57
Q

As it is stress
that usually excites the sympathetic system, it is frequently said that the sympathetic system
provides extra energy to the body for a state of stress, and this is often called the

A

alarm reaction or stress reaction

58
Q

Acetylcholine is the

A

transmitter at all autonomic ganglia and the receptors are designated as nicotinic

59
Q

The transmitter at the postganglionic parasympathetic nerve ending is acetylcholine and the synapse

A

is cholinergic

60
Q

The transmitter at the postganglionic sympathetic nerve ending is norepinephrine and these
receptors have been

A

designated adrenergic

61
Q

It is prudent to consider three of these types of adrenergic receptors. Alpha
(α) receptors are located predominantly on

A

smooth muscle, e.g. blood vessels, gastrointestinal

muscle, and uterus.

62
Q

Beta (β) receptors can be sub-divided into β1 and β2. β1 receptors are found in the heart,
and when activated, increase the force and rate of contraction of the heart. β2 receptors are found
in the lungs, blood vessels, gastrointestinal muscle and uterus, and activation of these receptors
leads to

A

muscle relaxation