coordination and response

Question 1

stimuli

Answer 1

changes in the environment that can be detected by organisms

Question 2

receptors

Answer 2

cells or groups of cells that detect stimuli
may be specialised cells or endings of sensory neurons

Question 3

effectors

Answer 3

part of the body that respond to a stimulus; muscles and glands

Question 4

coordination

Answer 4

ensuring that the actions of different parts of the body work together
the way in which the receptors detect stimuli and then pass the info on to the effectors

Question 5

nerve

Answer 5

a group of neuron axons lying together
used to send information from receptors to effectors

Question 6

why does there need to be a communication between the receptors and effectors

Answer 6

to make sure you don’t get hurt or for animals that they can quickly catch food.

Question 7

what makes up the nervouse system

Answer 7

receptors to effectors
neurons

Question 8

2 ways for sending information from receptors to effectors

Answer 8

nervous system
(slower) hormones, endocrine system

Question 9

neuron

Answer 9

a cell that is specialised for conducting electrical impulses rapidly

Question 10

structure of a neuron

Answer 10

same as any animal cell
structure is specially adapted to carrying electrical signals quickly.
>long thin fibres of cytoplasm stretching out of the cell, the longest one is called the axon
>axons can be a meter long,
>shorter fibres called dendrites, pick up electrical signals from other neurons close by. (nerve impulses)
>the signal passes to the cell body, then along the axon, which might pass it to another neurone.

Question 11

motor neurone

Answer 11

a neurone that transmits electrical impulses from the central nervous system to an effector

Question 12

axon

Answer 12

a long, thin, fibre of cytoplasm that extends from the cell body of a neurone

Question 13

dendrites

Answer 13

short fibres of cytoplasm in a neuron

Question 14

nerve impulses

Answer 14

an electrical signal that passes rapidly along an axon

Question 15

myelin

Answer 15

axon is wrapped in a layer of fat and protein called myelin.
insulates the nerve fibre, so that they can carry them faster

Question 16

central nervous system (CNS)

Answer 16

made up of the brain and spinal cord
made up of neurones
its role is to coordinate the electrical impulses traveling through the nervous system

Question 17

peripheral nervous system (PNS)

Answer 17

made up of nerves spread out from the CNS
includes receptors in our sense organs

Question 18

what happens when a receptor detects a stimuli

Answer 18

it send an electrical impulse along a neutron to the brain or spinal cord.
they recieve the impulse and send the impulse along the appropiate nerve fibres, to the appropiate effector.

Question 19

sensory neurone

Answer 19

a neurone that transmits electrical impulses from a receptor to the central nervous system

Question 20

relay neurone

Answer 20

a neurone that transmits electrical impulses within the CNS

Question 21

reflex action

Answer 21

the reaction that happens after the impulse has sped around the reflex arc

Question 22

reflex arc

Answer 22

pathway along in which the nerve impulses passes the sensory neurone, relay neurones and motor neurones. from the receptor to the effector

Question 23

why are reflex actions useful

Answer 23

bc info moves very quickly without us even thinking abt it.

Question 24

synapse gap

Answer 24

the gap between each neurone

Question 25

synapse

Answer 25

the ends of the neuron on either side of the gap + the gap. the junction between the gap.

Question 26

vesicle

Answer 26

a very small vacuole

Question 27

neurotransmitter

Answer 27

a chemical stored in vesicles at the end of neurones, which can be released to diffuse across the synaptic gap and set up an electrical impulse in the next neurone

Question 28

receptor proteins

Answer 28

proteins on the membrane of the second neurone at a synapse, which have a complementary shape to the molecules of neurotransmitter

Question 29

sense organ

Answer 29

a group of receptor cells in the retina. these receptor cells are sensitive to light

Question 30

retina

Answer 30

part of the eye that contains the receptor cells sensitive to light tissue at the back of the eye

Question 31

conjuntiva

Answer 31

thin transparent membrane covering the front of the eye protects parts behind it

Question 32

how is the surface of the eye kept moist

Answer 32

by a fluid in the tear glands. contains an enzyme that kills bacteria when you blink the fluid is washed across your eye.

Question 33

optic nerve

Answer 33

the nerve that carries electrical impulses from the retina to the brain. when light falls on the receptor cell in the retina it send an electrical impulse to the optic nerve.

Question 34

blind spot

Answer 34

part of the retina where he optic nerve leaves and there are no receptor cells

Question 35

fovea

Answer 35

the part of the retina where the cone cells are very tightly packed; this is where light is focused when you look directly at an object mostly contains cones

Question 36

the 2 kinds of receptor cells

Answer 36

rods- sensitive to dim light, dont respond to colour. allow us to see in dim light (black and white), spread out along the retina = less detailed image cones- can distinguish between colours of light but only function when the light is bright. give us color vision, tightly packed to produce a sharp image

Question 37

iris

Answer 37

in front of the lens circular piece of tissue coloured piece of your eye contains pigments which absorb lgiht (dont pass through) in the middle of the iris is the pupil (a gap)

Question 38

pupil

Answer 38

circular gap in iris light passes through size can be adjusted wider= more light (in dim light) narrow= less light (in bright light) to not damage retina

Question 39

how does the pupil adjust size

Answer 39

circular muscles around the pupil contract= pupil gets smaller radial muscles run outward from pupil contract= dilate

Question 40

iris reflex

Answer 40

an automatic response to a change in lgiht intensity; the receptors are in the retina, and the effector is the muscles in the iris

Question 41

antagonist muscles

Answer 41

the circular and radial muscles

Question 42

refraction

Answer 42

bending light rays so thy focus exactly on the retina the cornea does this

Question 43

cornea

Answer 43

a transparent layer near the front of the eye, which refracts light rays entering the eye

Question 44

lens

Answer 44

a transparent structure in the eye, which changes shape to focus lgiht rays onto the retina

Question 45

accomodation

Answer 45

changing the shape of the lens to focus on the objects at different distances from the eye

Question 46

suspensory ligaments

Answer 46

strong inelastic fibres that hold the lens in position; when they are under tension, they pull the lens into a thinner shape

Question 47

ciliary muscles

Answer 47

a circle of muscle surrounding the lens, and joined to it by the suspensory ligaments; when it contracts, it slackens the ligaments so that the lens becomes fatter

Question 48

hormones

Answer 48

chemicals that are produced by a gland and carried in the blood, which alter the activites of their specific target organs secreted in endocrine glands pass from the gland into the blood plasma.

Question 49

target organ

Answer 49

organs who's activity is altered by a hormone

Question 50

adreneline

Answer 50

hormone secrete by the adrenal glands above the kidneys prepares your body for flight of fight

Question 51

adrenalines effect

Answer 51

heart beats faster > more quickly oxygen to your brain and muscles >muscles to carry out aerobic respiration more quickly, more energy for running breathing rate increase> more oxygen to lungs pupils to dilate> more light> see more liver to release more glucose into the blood> for muscles > metabolic activity increases

Question 52

how do plants react to stimuli

Answer 52

by changing their growth towards or away from stimuli

Question 53

tropism

Answer 53

a growth response by a plant; on which the direction of growth is related to the direction of the stimulus

Question 54

phototrpopsim

Answer 54

a response in which a part of a plant grows towards or away from the direction from which the light is coming

Question 55

gravitropism

Answer 55

a response in which part of a plant grows towards or away from gravity shoots grow have negative gravitropism, roots the oppisite

Question 56

auxin

Answer 56

a plant hormone made in the tips of shoots, which causes cells to elongate