Topic 5 Nervous system / neurons

Question 1

The 2 main subdivisions of the nervous system ?

Answer 1

Central nervous system (CNS) & Peripheral nervous system (PNS)

Question 2

The central nervous system consists of?

Answer 2

Brain and spinal cord

Question 3

The peripheral nervous system consists of ?

Answer 3

All nervous tissue outside of the CNS.

Question 4

What are the Functions of the NS? (3)

Answer 4

Sensory - detection and input (towards CNC)

Integrative - processing/storing/ analyzing of sensory info;
Decision making

Motor - output (role of PNS)

Question 5

Types of tissue…

Nervous tissue is designed for what?

Answer 5

Communication

Question 6

Name the types of cells?

Answer 6

Neurons and neuroglia

Question 7

Role of the neuroglia (glia cells)?

Answer 7

Support, nourish, protect

Question 8

Name the 3 parts of the Neurons ( nerve cell)

Answer 8

Dendrite, cell body, axon

Question 9

Is the input portion of the neuron;

Contains lots of receptor sites for receiving chemical messages from other cells

Answer 9

Dendrite

Question 10

Part of neuron that is responsible for cell processes;

Contains the neucleus and other organelles

Answer 10

Cell body

Aka soma, perikaryon (holds nucleus DNA/RNA)

Question 11

A thin cylindrical process off the cell body;

It is the output portion of the neuron

Answer 11

Axon

Question 12

The end of the axon divides into many fine processes called?

Answer 12

Axon terminals

Question 13

The swollen ends of the axon terminals?

Answer 13

Synaptic end bulb

Question 14

Def.
A multilayered lipid and protein covering that speeds up signal conduction
Signal = action potential

Answer 14

Myelin

*myelin insulates to aid the speed of communication

Question 15

Some axons are myelinated; axons coated in myelin are called?

Answer 15

Myelinated axons

Question 16

These possess electrical excitability;

Can respond to a stimulus and convert it to an action potential(AP)

Answer 16

Neuron

Question 17

Def.

Any change in the environment (internal external) that is strong enough to stimulate an Action Potential (AP)

Answer 17

Stimulus

Question 18

Def.
An electrical signal that travels along the cell membrane of a neuron;
Influenced by myelin, they travel at different speeds

Answer 18

Action potential (AP)

Question 19

Neurons vary in size and shape;

Structural, they are classified according to the number of processes extending from the cell body - name the 3 types

Answer 19

Multipolar
Biopolar
Unipolar

Question 20

Neuron structure…
Several dendrites and one axon
* most neutrons in the brain and spinal cord and all motor neurons

Answer 20

Multipolar

Question 21

Neuron structure…
One main dendrite and one axon
*retina, inner ear, olfactory system

Answer 21

Bipolar

Question 22

Neuron structure…
Peripheral axon has sensory receptors;
Central axon has a on terminals;
*Sensory neutrons in the PNS are —-

Answer 22

Unipolar

Question 23

Functionally, neurons are classified according to the direction in which the AP is conducted - name the 3 types

Answer 23

Sensory neurons
Motor neurons
Interneurons

Question 24

Most are unipolar;
Contain either sensory receptors at the ends or are located just after sensory receptors that are separate cells
Once activated by a stimulus, the AP forms and propagates along the axon and is conveyed into the CNS by these
They travel together in spinal and cranial nerves

Answer 24

Sensory neurons

Aka Afferent neurons

Question 25

Are multipolar; | The AP propagates way from the CNS to the effectors via these

Answer 25

Motor neurons | Aka Efferent neurons

Question 26

Def. | The cells and organs (eg. Muscle fibres, glands

Answer 26

Effectors

Question 27

Most are multipolar Located primarily in the CNS between the sensory and motor neurons; They integrate/ process information from sensory neurons - If motor response is required, the specifics of the response are formulated and relevant motor neurone are activated.

Answer 27

Interneurons | Aka Association neurons

Question 28

Def. | The site of communication between two neutrons or between a neutron and another type of cell

Answer 28

Synapse

Question 29

There are 2 types of synapses

Answer 29

Electrical and chemical

Question 30

Type of synapse... APs conduct directly between the plasma membranes of adjacent cells through gap junctions Faster (than chemical) Allows for synchronization of function

Answer 30

Electrical synapses

Question 31

Chemical synapses - terms... | The neuron sending the signal

Answer 31

Pre-synaptic neuron

Question 32

Chemical synapses - terms... | The neutron receiving the signal

Answer 32

Post-synaptic neuron

Question 33

Chemical synapses - terms... | The space between the communication neurons

Answer 33

Synaptic clef

Question 34

Chemical synapses - terms... A chemical released by the pre-synaptic neuron to affect (excite inhibit) the post-synaptic neuron(s) or effector (muscle/glands)

Answer 34

Neurotransmitter (NT) | *NT receptors are specific to the NT released (think lock and key)

Question 35

Def. When the AP reaches the end of the pre-synaptic neuron, it causes the release of a neurotransmitter that diffuses across the synaptic clef, binds to the post-synaptic neuron

Answer 35

Chemical synapses

Question 36

If neurotransmitter is excitatory, continuation of the AP is ...

Answer 36

More likely

Question 37

If neurotransmitter is inhibitory, continuation of the AP is

Answer 37

Less likely

Question 38

Common Neurotransmitters (4)

Answer 38

Acetylcholine (ACh) Gamma-aminobutyric acid (GABA) Dopamine Serotonin

Question 39

Neurotransmitter found in the PNS/CNS, excitatory at neuro muscular junction

Answer 39

Acetylcholine

Question 40

Neurotransmitter found in the CNS, inhibitory

Answer 40

Gamma-aminobutyric acid | * regulate muscle tone, contractions

Question 41

Neurotransmitter that is excitatory or inhibitory (depending on receptors), emotional responses, addictive behaviours, skeletal tone

Answer 41

Dopamine | * emotional response

Question 42

Neurotransmitter that is excitatory or inhibitory (depending on receptor), sensory perception , temperature regulation, mood, sleep, appetite

Answer 42

Serotonin | * serotonin stays in the synaptic clef longer