co-ordination and response

Question 1

two systems that control the actions of organisms and allow them to respond

Answer 1

hormonal and nervous system

Question 2

homeostasis

Answer 2

the maintenance of a constant internal environment

Question 3

homeostasis eg

Answer 3

body water content and temperature

Question 4

what do the brain and spinal cord make up

Answer 4

central nervous system (CNS)

Question 5

Hormonal system

Answer 5

Hormones secreted by endocrine glands

Question 6

What is the CNS linked to by what

Answer 6

Linked to sense organs by nerves

Question 7

How does the nervous system work

Answer 7

Detects stimuli, which lead to responses by making muscles contract or glands release substances

Question 8

What does a co-ordinated response require

Answer 8

A stimulus, receptor and effector

Question 9

Co-ordinated response eg

Answer 9

Stimulus:light, receptor: retina, response:ability to see

Question 10

How does the CNS work

Answer 10

The stimulation of receptors in the sense organs send electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses by making

Question 11

Stimulus

Answer 11

A change in the external or internal environment

Question 12

Receptor

Answer 12

Detects the change and generates a nerve impulse which passes along the sensory neurone into the CNS

Question 13

Coordinator

Answer 13

Relay neurones take the impulse through the spine/brain, passing it on to the correct motor neurone

Question 14

Effector

Answer 14

A motor neurone takes the impulse out of the CNS to the correct effector organ (muscles, glands)

Question 15

Response

Answer 15

A reaction happens eg. muscle contraction or gland secretion

Question 16

Reflex actions are:

Answer 16

Rapid, Automatic (don’t require conscious thought) , Protective (evolved to protect our bodies)

Question 18

Reflex actions

Answer 18

Route a nerve impulse travels in a reflex response

Question 19

Sensory neurons

Answer 19

Have a sensory organ at one end

Question 20

Relay neurons

Answer 20

Pass the nerve impulse from one neuron to another

Question 21

Motor neurons

Answer 21

Can cause movement (because muscles contract) or glands produce eg. hormones

Question 22

Synapses

Answer 22

Gap between 2 neurones

Question 23

Neurotransmitters

Answer 23

Chemicals that cross the synapses, generate a nerve impulse in the neighbouring neurone. Specific and complementary to the receptor

Question 24

How synapses work

Answer 24

1. Nerve impulse arrives from axon of first neurone
2. Vesicle with neurotransmitter fuses with membrane
3. Neurotransmitter diffuses across synaptic gap
4. Neurotransmitter attaches to receptors on membrane of second neurone
5. Impulse started in second neurone
6. Neurotransmitter is broken down by enzymes

Question 25

Senses

Answer 25

Allow us to take in information in the form of a stimulus, which is detected by a receptor

Question 26

Sclera

Answer 26

A white layer that surrounds the eye, protects the eye from injury

Question 27

Chloroid layer

Answer 27

Prevents the reflection of light rays inside the eyeball and contains blood vessels to provide retina with oxygen and glucose

Question 28

Retina

Answer 28

Layers of light sensitive cells (tissue) at the back of the eye that sends signals to the brain so that you can see

Question 29

Cornea

Answer 29

Direct light rays into the eye and helps focus them on the light sensitive rat at the back of the eye, providing sharp, clear vision

Question 30

Conjunctiva

Answer 30

Thin, transparent protective outer covering that lubricates the eye and prevents entry of microorganisms.

Question 31

Iris

Answer 31

The coloured part of the eye which surrounds the pupil. Regulates the amount of light that enters the eye.

Question 32

Pupil

Answer 32

The portal which allows a regulate the flow of light to the retina

Question 33

Fovea

Answer 33

Responsible for sharp central vision

Question 34

Blind spot

Answer 34

Where the optic nerve leaves the retina so that the receptor cells. Like that goes to the point doesn’t form an image

Question 35

Optic nerve

Answer 35

Translate sensory information in electrical impulses to the brain

Question 36

Lens

Answer 36

Focuses and directs light onto the retina

Question 37

Suspensory ligaments

Answer 37

A series of fibres that connect the ciliary body of the eye with the lens, holding it in place

Question 38

Ciliary muscle

Answer 38

Changes the shape of the lens of the eyeball and contains to focus on objects at different distances

Question 39

Eye for long distance

Answer 39

The ciliary muscles relax, suspensory ligaments pull tight, lens pulls thin, light doesn’t bend as much

Question 40

Eye for short distance

Answer 40

Ciliary muscles contract, lens fattens, light bends more

Question 41

Eye in bright light

Answer 41

Circular muscles contract, radial muscles relax, pupils constricted

Question 42

Eye in dim light

Answer 42

Radial muscles contract, circular muscles relax, pupils dilated

Question 43

Receptors (transducers)

Answer 43

They all convert the stimulus energy into the electrical energy of a nerve impulse

Question 44

Things that have to be kept the same in our body

Answer 44

-pH -temperature -water potential -blood glucose

Question 45

Negative feedback

Answer 45

A change in the body is detected and brings about events that return conditions to normal

Question 46

Blood vessels when you’re too hot

Answer 46

The ones supplying the skin Dilate (vasodilation) so more blood flows closer to the surface. More heat is lost by radiation, which cools you down

Question 47

Blood vessels when your too cold

Answer 47

The ones supplying the skin constrict (vasoconstriction), less blood flows so less heat is lost by radiation, stops you getting cold.

Question 48

Sweat gland when you’re too hot

Answer 48

More sweat, more heat lost by evaporation

Question 49

Sweat glands when you’re too cold

Answer 49

Less sweat, less evaporation so less energy in transferred from the body to the surroundings

Question 50

Skeletal muscles when you’re too hot

Answer 50

No shivering/ spontaneous contractions

Question 51

Skeletal muscles when you’re too cold

Answer 51

Shivering releases heat as muscles respire at a higher rate

Question 52

Erector pili muscles when you’re too hot

Answer 52

Relax so hairs lie flat

Question 53

Erector pili muscles when you’re too cold

Answer 53

Contract so trap a layer of air that insulates the body