Chapter 1 Flashcards
(49 cards)
1
Q
what is the human nervous system
A
an important control system in body coordination
2
Q
Human nervous system consists of two types:
A
- central nervous system
- peripheral nervous system
3
Q
Which parts are related to central nervous system
A
- brain
-spinal cord
4
Q
Which parts are related to peripheral nervous system
A
- 12 pairs of cranial nerves ( connect brain to sensory & internal organs)
- 31 pairs of spinal nerves (connect spinal cord to skeletal muscles)
5
Q
State main function of hns
A
controls n coordinates organs & parts of the body
6
Q
State other functions of hns
A
- detects stimuli
- interprets impulses
- send information in form of impulses
- produce appropriate responses
- maintains a balanced internal enviroment
7
Q
Cornea layer:
A
- transparent layer
- refracts n focuses light onto the retina
8
Q
Iris:
A
- coloured part of the eye
- controls the size of the pupil
9
Q
Pupil:
A
- opening in the centre of the iris
- controls the quantity of the light entering the eye
10
Q
Aqueous Humour
A
- transparent fluid
- maintains the shape of the eyeball
- focuses light into the eye
11
Q
Conjuctiva
A
- transparent membrane
- protects the front part of the sclera
12
Q
Vitreous humour
A
- transparent jelly like substance
- maintains shape of the eyeball
- focuses light onto the retina
13
Q
Blind Spot
A
- part of the retina thats not sensitive to light as there are no photoreceptors
- an exit point for all optic nerves fibres
14
Q
Optic nerves
A
- nerve fibres
- carry nerve impulses frm retina to brain to be interpreted
15
Q
Yellow Spot
A
- part of the retina
- most sensitive to light = many photoreceptors
16
Q
Retina
A
- Layer containing photoreceptors
- detects light
- produces nerve impulses
17
Q
Explain more on the photoreceptors found in the retina
A
Two types:
Rod Cells: senstive to diff light intensities
Cone cells: sensitive to the colors of light
(each is sensitive to diff types of light) red, green and blue light
18
Q
Choroid
A
- black layer
- prevents reflection of light in the eye
- supplies oxygen and nutrients to the eye
19
Q
Sclera
A
- strong layer
- maintains shape of the eye
- protects the eye
20
Q
Eye Lens
A
- transparent and elastic convex lens
- focuses light onto the retina
21
Q
Ciliary Muscle
A
- Muscle that changes the thickness of the eye lens
-> through contractions & relaxations
22
Q
Suspensory ligaments
A
- strong fibres
- hold the eye lens in its position
23
Q
3 parts in a ear
A
outer ear
middle ear
inner ear
24
Q
outer ear consists of
A
earlobe
ear canal
25
middle ear consists of
eardrum
ossicles
oval window
eustachian tube
26
inner tube consists of
cochlea
semicircular canals
auditory nerve
27
function earlobe
collects n directs sound waves into the ear canal
28
function ear canal
directs sound waves to the eardrum
29
function of eardrum
thin membrane vibrates according to the frequency of the sounds waves received & transfers the vibration to ossicles
30
function of ossicles
made of 3 small bones to amplify sound vibrations and transfer them to the oval window
31
Function oval window
collect and transfer sound vibrations frm ossicles to the cochlea
32
function eustachian tube
balance the air pressure on both sides of the eardrum
33
function cochlea
detects and converts sound vibrations into nerve impulses
34
function semicircular canals
contains fluid , detect position of the head n help to balance the body
35
function auditory nerve
send nerve impulses frm cochlea to the brain to be interpreted
36
which 2 structure of the ear arent used in the hearing process
- eustachian tube
- semicircular canals
37
State the flow of path of light
cornea---> AH----> Pupil ---> eye lens -----> VH---> Retina-----> optic nerves-----> brain
38
When does an optical illusion occur
an object that is seen differs frm its actual state
39
Why do optical illusions happen
the brain is unable to accurately interpret the object seen by the eye due to distractions around the object
40
What is the meaning of tropism
directional response of plants to stimuli
41
The part of plant which grows towards a stimulus is known as
positive tropism
42
the part of plant which grows away from a stimulus is known as
negative tropism
43
why do plants need to responsive towards stimuli such as light , gravity n water
So that they can appropriately to ensure their sustainability n survival
44
name the 4 types of tropism
phototropism
hydrotropism
geotropism
thigmotropism
45
Explain phototropism
- response of plants towards light
- shoots of plants show positive phototropism
46
explain hydrotropism
- response of plants towards water
- roots plants show positive hydrotropism
- absorb dissolved mineral salts to stay alive
47
explain geotropism
- towards gravity
- roots of plants show positive geotropism
- pg allow roots grow deep into the ground to grip n stablilise the position of the plant in the ground
- shoots show negative tropism
- ng allow shoot n leaves to obtain sunlight
48
explain thigmotropism
- response towards touch
- tendrils or twining stems show positive
- pt enables plants to grow upwards obtain sunlight, grip objects to obtain support
- roots show negative thing bc avoid object that obstruct their search for water
49
Nastic movement
- response towards touch
- does not depend on direction of stimulus
- occurs more rapidly than tropism
- serves as a defence
