17.1 quiz

Question 1

What is the PNS

Answer 1

The peripheral nervous system

Question 2

What does the PNS consist of (3 parts)

Answer 2

• The somatic nervous system

- Autonomic nervous system: parasympathetic and sympathetic division.

Question 3

What is the CNS

Answer 3

the central nervous system

Question 4

What does the CNS consist of

Answer 4

The brain and spinal cord.

Question 5

What is the difference between the CNS and the PNS

Answer 5

PNS is everything but brain and spinal cord,

Question 6

What are the 3 types of neurons?

Answer 6

• Sensory
• Inter
• Motor

Question 7

What is a sensory neuron?

Answer 7

A neuron that recognizes external stimuli and converts it to internal electrical impulses.

Question 8

Where are sensory neurons located?

Answer 8

In clusters in the dorsal root ganglia by the spinal cord. With axons that extend outwards

Question 9

Where do sensory neurons send impulses

Answer 9

To central nervous system - brain

Question 10

What are motor neurons

Answer 10

A neuron whose axon indirectly or directly controls effector organs (muscles and glands)

Question 11

Where are motor neurons located?

Answer 11

In motor cortex (spinal cord)

Question 12

What are interneurons?

Answer 12

A neuron that transmits impulses from other neurons, or between neurons and CNS.

Question 13

Where are interneurons located?

Answer 13

In Central Nervous System only.

Question 14

What are the three parts of a neuron?

Answer 14

Dendrites, axon, axon terminals

Question 15

What does the dendrite of a neuron do?

Answer 15

Transmit signals from other nerve cells to cell body.

Question 16

What does the axon of a neuron do?

Answer 16

Transmit signals from cell body to other nerve cells

Question 17

What does an axon terminal do?

Answer 17

At the end of the axon, sends signal to synapse (space between nerve cells)

Question 18

What do you call the potential difference across the membrane of a RESTING neuron?

Answer 18

resting potential

Question 19

How is the resting potential of an axon maintained?

Answer 19

Sodium potassium pumps

Question 20

How do sodium potassium pumps work?

Answer 20

Actively transport Na+ out of axon and K+ into axon

Question 21

Why is the axon charged negatively at rest?

Answer 21

Because there are more + ions outside than inside axon

Question 22

What do you call the rapid change in polarity across an axonal membrane as nerve impulse occurs?

Answer 22

An action potential

Question 23

What two gated channel proteins are required in an action potential?

Answer 23

Na+ and K+ gates.

Question 24

What are the steps of an action potential?

Answer 24

Depolarization, repolarization, refractory phase.

Question 25

What do you call it when the Na+ gates open and Na+ moves into the axon, causing the membrane potential to jump from -70 to +35 mV?

Answer 25

Depolarization

Question 26

What do you call it when the K+ gates open and K+ leave ion, causing membrane potential to jump from +35 mV to -90 mV?

Answer 26

Repolarization

Question 27

How long does an action potential last?

Answer 27

A few seconds

Question 28

What is the refractory period (non-myelinated axons)?

Answer 28

The period after an action potential where the neuron can’t have another quite yet as sodium gates can’t open.

Question 29

How do action potentials occur in myelinated axons?

Answer 29

They travel faster as they are concentrated in nodes of ranvier, where they jump from node to node.

Question 30

What do you call it when an action potential jumps from node to node?

Answer 30

Saltatory conduction.

Question 31

What do you call the insulated covering around an axon?

Answer 31

The myelin sheath

Question 32

What is the function of the myelin sheath?

Answer 32

• Speeds up impulse travelling on axon.

- Cause impulse to hop rather than travel in waves.

Question 33

How is myelin made in the PNS?

Answer 33

by Schwann cells

Question 34

How is myelin made in CNS?

Answer 34

oligodendrocytes

Question 35

What is the somatic nervous system?

Answer 35

Voluntary control of body movements

Question 36

What is the autonomic nervous system?

Answer 36

Involuntary control (heartrate, digestion, etc.)