B5 - Homeostasis and Response

Question 1

what is homeostasis

Answer 1

the regulation of internal conditions of a cell or an organism to maintain optimum conditions for function in response to internal and external changes

Question 2

what does homeostasis do

Answer 2

maintains optimal conditions for enzyme action and all cell functions

Question 3

what 3 things must be kept at optimal levels

Answer 3

blood glucose concentration
body tempreature
water levels

Question 3

what do all control systems include

Answer 3

receptor cells which detect stimuli
coordination centres which receive and process information from receprtos

Question 4

what do all control systems include

Answer 4

receptor cells which detect stimuli
coordination centres which receive and process information from receptors
effectors which bring about responses to restore optimum levels

Question 5

what does the nervous system enable

Answer 5

humans to react to their surroundings and coordinate their behaviour

Question 6

what is the central nervous system and how is it connected to the body

Answer 6

the brain and spinal cord
connected to the body with sensory neurons and motor neurons

Question 7

what are sensory neurons

Answer 7

neurons that carry the information as electrical impulses from the receptors to the CNS

Question 8

what are motor neurons

Answer 8

neurons that carry electrical impulses from the CNS to effectors

Question 9

what are effectors

Answer 9

muscles and glands which respond to nervous impulses

Question 10

describe what happens when we respond to stimuli

Answer 10

information from the receptors passes along cells as electrical impulses to the cns where it coordinates the response of the effectors which may be muscles contracting and glands secreting hormones

Question 11

complete:
stimulus —> …..

Answer 11

stimulus —-> receptor —> coordinator —> effector —> response

Question 12

what are reflex actions

Answer 12

actions which are automatic and rapid and dont involce the consious part of the brain

Question 13

what connects neurons together

Answer 13

synapses

Question 14

describe what happens at a synapse

Answer 14

the nerve signal is transferred by chemicals which diffuse across the gap

Question 15

why are reflex actions improtant

Answer 15

they help to prevent injury

Question 16

what does the brain do

Answer 16

control complex behaviour

Question 17

what does the cerebral cortex do

Answer 17

responsible for things such as consciousness, memory, language, intelligence

Question 18

what does the medulla do

Answer 18

controls unconscious activities such as breathing and heart rate

Question 19

what does tje cerebellum do

Answer 19

responsible for muscle coordination

Question 20

what are some difficulties with investigating brain function

Answer 20

as it is complex and delicate so there is a risk of damaging the brain or increased problems with the brain function

Question 21

how have scientists been able to match different functions of the brain to different areas

Answer 21

by electrically stimulating different parts of the brain from people with brain damage using MRI.

Question 22

what is the eye

Answer 22

a sensor organ containing receptors sensitive to light intensity and colour