L21

Question 1

What is the main function of the nervous system?

Answer 1

Communication and coordination network using electrical signals (nerve impulses).

Question 2

What are the two main divisions of the nervous system?

Answer 2

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Question 3

What does the Central Nervous System (CNS) include and do?

Answer 3

Brain and spinal cord; interprets signals and sends responses (integration center).

Question 4

What does the Peripheral Nervous System (PNS) include and do?

Answer 4

Network of nerves outside the CNS; relays information to and from the CNS.

Question 5

What is the function of the neuron’s cell body?

Answer 5

Contains the nucleus and most organelles.

Question 6

What is the function of dendrites?

Answer 6

Carry impulses toward the cell body.

Question 7

What is the function of an axon?

Answer 7

Carries impulses away from the cell body.

Question 8

What is the function of the myelin sheath?

Answer 8

Insulates some nerves; allows faster signal transmission.

Question 9

What is the function of the synaptic terminal?

Answer 9

Relays signals to receiving cells.

Question 10

What is the function of the Sympathetic Nervous System?

Answer 10

Triggers ‘Fight or Flight’ response.

Question 11

What is the function of the Parasympathetic Nervous System?

Answer 11

Controls ‘Rest and Digest’ or ‘Feed and Breed’ functions.

Question 12

What do sensory receptors do?

Answer 12

Convert external stimuli into electrical impulses sent to the CNS.

Question 13

What do thermoreceptors detect?

Answer 13

Heat and cold.

Question 14

What do mechanoreceptors detect?

Answer 14

Pressure, sound, or stretch (mechanical stimuli).

Question 15

What do nociceptors detect?

Answer 15

Tissue damage (pain).

Question 16

What do chemoreceptors detect?

Answer 16

Chemical stimuli (taste, smell, O2/CO2 levels).

Question 17

What do photoreceptors detect?

Answer 17

Light for vision.

Question 18

What are nerve impulses called?

Answer 18

Action Potentials (AP).

Question 19

What causes action potentials?

Answer 19

Movement of Na+ and K+ ions across the plasma membrane.

Question 20

What is resting potential?

Answer 20

Polarized membrane before stimulation.

Question 21

What happens when a stimulus reaches threshold?

Answer 21

Na+ channels open and Na+ rushes in (depolarization).

Question 22

What happens during repolarization?

Answer 22

K+ channels open and K+ ions rush out, restoring potential.

Question 23

How does an action potential travel?

Answer 23

It is self-propagating and moves down the axon.

Question 24

What happens when an action potential reaches the synaptic terminal?

Answer 24

Ca2+ enters the terminal and stimulates vesicles.

Question 25

What do vesicles do during synaptic transmission?

Answer 25

Fuse with the presynaptic membrane and release neurotransmitters.

Question 26

What happens after neurotransmitters are released?

Answer 26

They cross the synaptic cleft and bind to receptors on the receiving cell.

Question 27

What is the result of neurotransmitter binding?

Answer 27

Ion channels open, possibly generating a new AP or muscle contraction.

Question 28

How is the neurotransmitter removed after signaling?

Answer 28

It is broken down or reabsorbed by the sending neuron (reuptake).

Question 29

How can drugs and toxins affect synaptic transmission?

Answer 29

They can promote, interfere with, or mimic neurotransmitter action.

Question 30

How does Botox affect neurotransmission?

Answer 30

Prevents release of acetylcholine (ACh) from axon terminals.

Question 31

How does VX nerve agent affect neurotransmission?

Answer 31

Blocks acetylcholinesterase, preventing ACh breakdown.

Question 32

How does cocaine affect neurotransmission?

Answer 32

Blocks dopamine reuptake, keeping dopamine in the synapse longer.

Question 33

How does nicotine affect neurotransmission?

Answer 33

Mimics acetylcholine by binding to its receptors.

Question 34

How does caffeine affect neurotransmission?

Answer 34

Blocks inhibitory adenosine receptors, increasing alertness.

Question 35

What does 'good enough' mean in sensory systems?

Answer 35

Evolution shaped senses to be adequate, not perfect.

Question 36

Is sensory experience an objective measure of reality?

Answer 36

No, it is a constructed perception, not an exact reflection of reality.

Question 37

What is sensory adaptation?

Answer 37

Reduced sensitivity from repeated stimulation; prevents overload.

Question 38

What happens if sensory structures are altered?

Answer 38

Structural changes can impair or eliminate receptor function (not detailed in source).