nervous system

Question 1

what is CNS consist of

Answer 1

brain and spinal cord

Question 2

what peripheral nervous system

Answer 2

sensory neurones, motor neurones

Question 3

comparison of nervous system and endocrine system

Answer 3

the nervous system is very rapid and the endocrine system is very slow

in the nervous system, electrical impulses travel along the nerves. in endocrine system, chemical messengers travel by bloodstream

example of nervous system: blinking
example of nervous system: growth

Question 4

what is the end of neurone called and its purpose

Answer 4

synapse. a tiny gap between nerve cells, the impulse only can travel this gap in one direction

Question 5

how do impulse travel across synapse

Answer 5

impulse arrives
there are neurotransmitters at the endplate
the chemical is released into the gap
the chemical diffuses across the gap and the impulse restarts on the other side

Question 6

feature of motor neurone

Answer 6

dendrites- collect information from other cells

axon- a long fibre which carries information away from the cell body, over long distances

fatty sheath made of myelin- gives electrical insulation between neighbouring cells and makes impulses travel faster

Question 7

which feature do relay neurone don’t have compared to a motor and sensory neurone

Answer 7

fatty sheath

Question 8

describe reflex action

Answer 8

receptor receive stimulus and convert it into electric impulse

sensory neurone carries the impulse to CNS

relay neurone carries impulse slowly across spinal cord, carry impulse from the brain

the motor neurone carries impulse from the CNS to effector

effector carries out an action

Question 9

what is a reflex action

Answer 9

rapid automatic response to a stimulus. all reflex actions have evolved to help us survive. a reflex is an involuntary action

Question 10

what is a voluntary action

Answer 10

a conscious decision is involved for voluntary actions

actions need to be learnt

slower than involuntary actions

Question 11

what is an involuntary action

Answer 11

reflexes

no conscious decision though the person is aware

rapid

same stimulus results in the same response

Question 12

what is sense organs

Answer 12

a group of receptor cells responding to specific stimulo

Question 13

example of stimuli

Answer 13

light, sound, touch, temperature

Question 14

what is fovea

Answer 14

the area has the highest density of cones so offers maximum sharpness

Question 15

another term for exit point of the optic nerve

Answer 15

blind spot

Question 16

what is cornea

Answer 16

a transparent layer for refraction of light rays that enters the eye

Question 17

the feature of the image formed on the retina

Answer 17

inverted and diminished

Question 18

the process of the brain correcting the inversion and reduction in the size of the image

Answer 18

integration

Question 19

what happens to the suspensory ligaments and ciliary muscle when looking at a distant object

Answer 19

ciliary muscle relax, eyeball becomes spherical
ligaments become tight

because light needs to be refracted less so the lens needs to be long and thin

Question 20

what happens to the suspensory ligaments and ciliary muscle when looking at a closed object

Answer 20

ciliary muscles contract, pull eyeball inwards
ligaments relax

because light needs to be refracted more so the lens becomes short and fat

Question 21

what happens to the pupil when light intensity decreases

Answer 21

radical muscles of the iris contract

circular muscle relax

Question 22

what happens to the pupil when light intensity increases

Answer 22

circular muscles of the iris contract

radical muscle relax

Question 23

what is an endocrine system

Answer 23

a series of organs called glands, which secretes chemicals called hormones

Question 24

where does adrenaline secreted

Answer 24

adrenal glands

Question 25

what is the effect of adrenaline

Answer 25

heat beats more rapidly,
deeper and rapid breathing
glycogen in muscles is converted to glucose
skin becomes pale

Question 26

effect of testosterone in sporting performance

Answer 26

stimulates male’s aggressive behaviour

Question 27

why do specific hormone only work for specific function

Answer 27

the specific receptors in the cell membranes only react to specific hormones