B9.1 - Nervous control in humans

Question 1

what are the systems involved in coordination and response in humans?

Answer 1

nervous system and hormonal (endocrine) system

Question 2

what is the nervous system?

Answer 2

its a system involved in coordination and response in humans. it includes the brain, the spinal cord, the peripheral nerves and specialised sense organs.

Question 3

what is stimulus mean?

Answer 3

a change in condition

Question 4

what do you need for a coordinated response to occur?

Answer 4

receptor organ and effector

Question 5

what is the hormonal (endocrine) system?

Answer 5

its a system involved in coordination and response in humans. it uses chemical communication by means of hormones.

Question 6

Name four human nervous system.

Answer 6

CNS, PNS, Receptor organs and effectors

Question 7

what is the CNS?

Answer 7

the brain and spinal cord which processes nervous impulses from the body and coordinates any response.

Question 8

what is the PNS?

Answer 8

all the nerves in the body that connects the CNS to other parts of the body.

Question 9

what is a receptor organ?

Answer 9

a bunch of receptors is a sense organ, it responses to a specific stimuli.

Question 10

what is a effector?

Answer 10

it produces the response , such as the contraction of muscles and the secretion of hormones from glands.

Question 11

what is a bundle of neurones?

Answer 11

a nerve

Question 12

how is the sense organs connected to the CNS?

Answer 12

nerves connect them together

Question 13

what is an special adaptation for a neurone?

Answer 13

it has many endings that connect with other neurones to pass on electrical impulses

Question 14

what are the three types of neurones?

Answer 14

sensory neurones, relay neurones, motor neurones.

Question 15

what does a sensory neurone do?

Answer 15

it carries impulses from sense organs to the CNS (brain or spinal cord).

Question 16

what does a relay neurone do?

Answer 16

its found inside the CNS and it connects the sensory neurone to the motor neurones

Question 17

what does a motor neurone do?

Answer 17

it carries impulses from the CNS to effectors (such as muscles or glands)

Question 18

what does neurones have?

Answer 18

Axons and Dendrons

Question 19

Describe and explain what a Axon is.

Answer 19

• its a long fibre which is insulated by a fatty sheath. this allows the impulse to travel quickly.
• Schwann cells form myelin sheath around axons.

Question 20

Describe and explain what a Dendron/dendrite is.

Answer 20

its tiny branches (dendrons) which branch further as dendrites at each end. this makes it easier to respond to the stimulus and pick up the impulses from many other neurones.

Question 21

Describe a sensory Neurone

Answer 21

its long and have a cell body branching off the middle of the axon

Question 22

Describe a relay neurone

Answer 22

its short and have a small cell body at one end with many dendrites branching off it.

Question 23

Describe a motor neurone

Answer 23

its long and have a large cell body at one end with long dendrites branching off it.

Question 24

what is the simplest type of response to a stimulus?

Answer 24

a reflex response

Question 25

what type of voluntary is a reflex response?

Answer 25

involuntary

Question 26

whats the pathway that impulses travel along during a reflex response called?

Answer 26

a reflex arc

Question 27

what the reflex arc pathway?

Answer 27

Stimulus --> receptor --> sensory neurone --> relay neurone in CNS (pass message to brain) --> motor neurone --> effector --> response

Question 28

is the simple reflex a spinal reflex or a reflex that involves that brain?

Answer 28

spinal reflex

Question 29

what is a spinal reflex?

Answer 29

its a impulse processed by the spinal cord, not the brain.

Question 30

is no impulse sent to the brain during a spinal reflex?

Answer 30

no, its still sent so the brain knows what happening. however the brain is not involved in this action.

Question 31

what does it mean to override a reflex response?

Answer 31

for example if your holding a large bowl of hot food , you might look around to find somewhere to put it down rather than dropping it straight away.

Question 32

what is a involuntary response (or reflex) ?

Answer 32

it doesnt involve the brain as the coordinator of the reaction.

Question 33

what is a voluntary response?

Answer 33

its where you make a conscious decision to carry out a particular action, so it starts with your brain.