Procetion And Control

Question 1

What is he central nervous system made up of ?

Answer 1

Brain and spinal cord.

Question 2

What is the peripheral system made of up ?

Answer 2

Any nerves in the body not the brain or spinal cord.

Question 3

What are the two parts of peripheral nervous system and what do they do?

Answer 3

Autonomic - controls body functions below the level of consciousness. Things we don’t think about, ie. heartbeat
Somatic- voluntary control of body movements, reflex.

Question 4

What are the 3 neurons the nervous system are composed of ?

Answer 4

Sensory neurons
Inter neurons
Motor neurons

Question 5

What do sensory neurons do ?

Answer 5

Carry impulses from the body to the spinal cord and brain

Question 6

What do inter neurons do ?

Answer 6

They are the neurons in the spinel cord and brain, they receive the signals from the sensory neurons and send it to the motor neurons)

Question 7

What do motor neurons do ?

Answer 7

Carry the response from the spinal cord or brain back out to the body. (Muscles or glands)

Question 8

What are the steps in the nervous system response ?

Answer 8

1. Receptors pick up the stimulus
2. Sensory neurons send the “hot” message to the CNS
3. The “hot” message is interpreted by the brain
4. A response is sent from the brain to the motor neurons
5. The motor neurons send a message to the muscles in the arm to move
6. Arm muscles are activated and move.

Question 9

What is the difference between CNS and PNS ?

Answer 9

CNS is the central nerve system, with only the brain and spinal cord
PNS is all the nerves in the body other than the brain and spinels cord

Question 10

What is a neuron ?

Answer 10

A nerve cell that conducts impulses throughout the nervous system.

Question 11

What do neurons do ?

Answer 11

They receive, process and transmit information as electrical and chemical signals around the nervous system.

Question 12

What does a dendrite do ?

Answer 12

Receives impulses and Carries them toward the cell body

Question 13

What is the function of the cell body ?

Answer 13

Is the “factory” of a neuron. It receives all the signals from the dendrites and passes them to the axon

Question 14

What is the function of the axon?

Answer 14

Carries impulses away from cell body toward other neurons, muscles or glass.

Question 15

What is the function of the myelin sheath ?

Answer 15

To protect the axon

Question 16

What is the function of the Schwann cell ?

Answer 16

To protect the axon.

Question 17

What is the function of the node of ranvier ?

Answer 17

Speeds up he nerve impulse.

Question 18

What would a neuron at rest look like ?

Answer 18

That there would be more K+ outside of the cell (extracellular) and less Na+ inside of the cell (intercellular)

Question 19

What channel opens first when an electrical response is occurring?

Answer 19

The sodium channels open first

Question 20

What are the 4 steps of a action potential ?

Answer 20

1. Resting
2. Depolarization
3. depolarization
4. Na+ /K+ pump to get back to resting.

Question 21

What happens in the repolarization part of action potential ?

Answer 21

The K+ channels open allowing the K+ to leave the cell making the outside of the cell positive

Question 22

In a synapse what are the 5 steps that occur ?

Answer 22

1 impulse reaches end of axon, calcium channels open, calcium enters end of axon

2. Calcium causes vessels in axon to fuse to plasma membrane, releasing their chemicals into the synapse
3. The chemicals (neurotransmitters) diffuse across the synapse and to the dendrites.
4. neurotransmitters open receptor site on new neuron, changing the polarity
5. Enzymes break down the neurotransmitters after they have initiated the new impulse to stop them from continually firing.