Homeostasis ONLY FOR AUTUMN TEST

Question 1

nervous system allows you to…

Answer 1

know what is going on in your surroundings

Question 2

the nervous system carries… travelling at between … and …m/s

Answer 2

electrical signals
1
120

Question 3

stimuli

Answer 3

changes

Question 4

receptors

Answer 4

• similar to animal cells
• found clustered together in special sense organs (e.g. eyes, skin)
• detects stimuli

Question 5

the path

Answer 5

1. sensory receptor detects stimulus
2. electrical impulse sent passing along sensory neurones
3. impulse reaches central nervous system
4. brain coordinates response + sends out impulses
5. travels along motor neurones to effectors
6. effector responds

Question 6

pathway condensed

Answer 6

stimulus, receptor, coordinator, motor neurone, effector

Question 7

Reflexes

Answer 7

• help to avoid danger because they happen so fast
• includes basic bodily functions e.g. breathing, digestingq

Question 8

3 kinds of neurone involved in pain withdrawal reflex

Answer 8

• sensory
• motor
• relay

Question 9

reflex arc

Answer 9

1. electrical impulse passes from receptor along the sensory neurones
2. arrives at CNS
3. passes along a relay neurone (usually in spinal cord)
4. and goes straight back along motor neurone
5. arrives at effector which responds

Question 10

reflexes details: receptor + sensory neurone

Answer 10

• when object is touched, receptor in the skin is stimulated
• electrical impulse is sent out along a sensory neurone

Question 11

reflex details: synapse + relay neurone

Answer 11

• when impulse arrives at synapse between sensory and relay neurone, a chemical is released
• chemical diffuses across synapse to relay neurone (in spinal cord so part of CNS)
• where it sets off a new electrical impulse which travels across relay neurone

Question 12

reflex details: relay -> motor neurone

Answer 12

• when the impulse reaches the synapse between motor and relay neurone, another chemical is released which diffuses across the synapse
• sending another impulse down the motor neurone

Question 13

reflex details: effector

Answer 13

• when impulse reaches effector organ its stimulated to respond
• impulses arrive in the muscles, causing to contract
• or reaches the gland, which secretes chemical substances

Question 14

difference between normal path and reflex path

Answer 14

coordinator is a relay neurone (in spinal cord or unconcious part of brain) instead of CNS

Question 15

reflex pathway

Answer 15

stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response

Question 16

effect of a factor on human reaction time: potential factors

Answer 16

• age
• temp
• alcohol
• drugs
• caffeine

Question 17

measuring reaction time methods

Answer 17

1. ruler drop test
2. stand in a circle holding hands eyes closed and see how long for squeeze to pass around

Question 18

peripheral nervous system

Answer 18

all other nerves connecting to the CNS, made up of neurons

Question 19

parts of a motor neurone

Answer 19

dendrite, cell body, nucleus, myelin sheath, axon, axon terminal

Question 20

which side does impulse come from on motor neurone

Answer 20

from cell body to axom terminal

Question 21

what are those chemical messengers called?

Answer 21

neurotransmitters

Question 22

how wide is the synapse

Answer 22

20 nanometres

Question 23

the neurotransmitter binds with a… which…

Answer 23

receptor molecule on the membrane of the postsynaptic neurone which stimulates a new nerve impulse im the postsynaptic neurone

Question 24

finally, the chemical messenger is… back into the… ready to be used again

Answer 24

reabsorbed
presynaptic neuron

Question 25

function of the brain

Answer 25

• information from sensory receptors feeds into the brain
• info is processed
• impulse is sent along a motor neurone to coordinate response

Question 26

parts of the brain + functions

Answer 26

cerebral cortex - memory, consciousness and intelligence
cerebellum - coordination of muscular activity and balance
medulla oblongata - unconcious acitivities e.g. heartbeat
hypothalamus - thermoregulation
pituitary gland - chemical messages (hormones)

Question 27

difficult to study brain bc…

Answer 27

• complex and delicate
• lots of neurones
• lots of pathways (synapses)
• encased by skull
• lots of neurotransmitters
• difficult to treat bc most medicines cant get in the brain
• surgery is hard as not all areas are fully understood

Question 28

techniques to ‘map’ the brain

Answer 28

• MRI scan
• autopsy/dissection
• electrically stimulating different parts
• studying people with brain damage