B9.1 - Nervous Control in Humans

Question 1

what is a nerve impulse?

Answer 1

an electrical signal that passes along nerve cells called neurons.

Question 2

what is the CNS made of?

Answer 2

made up of the brain and the spinal cord

Question 3

what is the pathway of the CNS/?

Answer 3

→ information is first received from the sensory neuron which then passes the information through the spinal and cord and processes the information in the brain.
→ after the information is received a response is made by the brain and passed through the relay neurons and motor neurons act on the response

Question 4

what is the PNS?

Answer 4

the system of nerves that connect the CNS to the skin, muscles and organs of the body

Question 5

what is the PNS made of?

Answer 5

made of skin, muscles and organs in the body

Question 6

what are the different types of neurons?

Answer 6

motor neuron, relay/intermediate neuron and sensory neurons.

Question 7

what is the function of sensory neurons?

Answer 7

• Detect signal

- Carry signals from receptors to the spinal cord then to the brain

Question 8

what is the function of intermediate/relay neurons?

Answer 8

• Carry messages from one part of the CNS to another

Question 9

what is the function of motor neurons?

Answer 9

• Trigger response

- Carry signals from the CNS to effectors such as muscles etc

Question 10

how do nerve cells connect to one another?

Answer 10

through the synapse

Question 11

what is the synapse?

Answer 11

Area where neurotransmitters are released from the previous neuron and they bind to certain receptors. From there a nerve impulse is passed to the next neuron and so on.

Question 12

what are examples of different sensory organs?

Answer 12

→ eyes : senses sight
→ ears : senses sound
→ nose : senses smell
→ skin  : senses touch 
→ tongue/ mouth : senses taste

Question 13

where are sensory neurons found?

Answer 13

in sensory organs

Question 14

where are motor neurons found?

Answer 14

They are found near effectors which are usually glands or muscles. They carry information from the CNs to cause a response.

Question 15

where are relay neurons found?

Answer 15

They are found in the CNS and connect sensory neurons to motor neurons

Question 16

what is the difference between involuntary and voluntary actions?

Answer 16

Voluntary response- requires conscious thought/ decisions to be made.

Involuntary responses- do not require conscious thought/ decision to be made. They are automatic responses and usually made to protect us from harm.

Question 17

what are the two types of reflexes?

Answer 17

Simple reflex
Conditioned reflexes (learned responses)

Question 18

what is a reflex arc?

Answer 18

A reflex arc is a nerve pathway

Question 19

what is the order of reflex arc?

Answer 19

• Sensory neuron detects stimuli
• Relay neuron connects sensory neuron to motor neuron
• The motor neuron is connected to an effector such as a muscles and stimulates a response
• The muscles then reacts