nervous control in humans

Question 1

nerve impulse

Answer 1

an electrical signal that passes along nerve cells called neurones

Question 2

the nervous system is made of

Answer 2

the central nervous system (CNS): consisting of the brain and spinal cord

the peripheral nervous system (PNS) consisting of all. the nerves connected to the brain and spinal cord

Question 3

what does the nervous system do?

Answer 3

coordinates and regulates all our bodily functions

Question 4

voluntary action

Answer 4

are those that are under our conscious control ie. we make a conscious desicion to make that response and not a different one

Question 5

involuntary response

Answer 5

are those that do not involve conscious control by the brain ie. they are caused by a reflex response

Question 6

describe the process of a reflex arc

Answer 6

the brain and spinal cord receive information from groups of receptor cells located in our sense organs. these receptor cells detect stimuli and then they send information in the form of an electrical impulse into the CNS along a special type of nerve cell called a sensory neurone

the CNS then send information out to an effector which will respond to the stimulus. the information is sent out along a motor neurone

the effector is always a muscle or a gland

Question 7

pathway

Answer 7

receptor cells —> CNS —> effector

Question 8

what is the connection between two neurones called?

Answer 8

a synapse

Question 9

a hormone is

Answer 9

a chemical substance produced by a gland that is carried by the blood. it alters the activity of one or more specific target organs

Question 10

what is adrenaline?

Answer 10

adrenaline is a hormone secreted into the blood by the adrenal glands which are located on top of each kidney

Question 11

effects of adrenaline on the body

Answer 11

• adrenaline dilates the pupil so more light can enter the eye
• adrenaline causes the heart rate to increase so the muscles are supplied with blood containing oxygen and glucose more quickly. this prepares them for action.
• adrenaline causes the breathing rate to increase to get more oxygen into the blood for the increased muscle activity and to remove co2
• stimulates the liver to concert glycogen into glucose and release it into the blood so that the blood glucose concentration increases

Question 12

adrenaline is often referred to as the

Answer 12

fight flight fright hormone

increaed physical activity or threatening situations

Question 13

comparing nervous and hormonal control systems- speed

Answer 13

nervous: quick
hormone: slower

Question 14

duration of effect

Answer 14

nervous: short lived
hormone: longer lasting

Question 15

form of transmission

Answer 15

electrical impulse

chemical substance- hormone

Question 16

what is a reflex action?

Answer 16

means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors

Question 17

what happens if someone sticks a pin into your hand?

Answer 17

receptor cells send an electrical impulse along a sensory neurone to the spinal cord. the spinal cord then sends an impulse out through a motor neurone to the biceps muscle which contracts to pull your hand away.

the brain is not involved in this response but is made aware of it afterwards

Question 18

what is a synapse?

Answer 18

the junction between two neurones