1 Flashcards
defintion of stimuli
chages in the surroundings/envirnment
structure of human nervous system
central nervous system & peripheral nervous system
central nervous system consists of?
brain & spinal cord
peripheral nervous system consists of?
cranial nerves & spinal nerves
pathway of impulse in a voluntary action
stimulus - affector - sends nerve impulse - brain - send nerve impulse - effector - receptor
definition of voluntary action
concious actions & conducted under one’s will
definition of involuntary action
actions that occur immediately without conscious control or prior thoughts
definition of reflex action?
an automatic & rapid response towards external stimuli to prevent more serious injuries
involuntary actions involve?
medulla oblongata
reflex actions involve?
spinal cord
pathway of impulse in an involuntary action (reflex action)
affector - effector - spinal cord - effector - affector
pathway of light
cornea - aquaous humour - eye lens - vitreous humour
explain cornea
transparent layer/refracts & focuses light onto the retina
explain aqueous humour
transparent fluid/ maintains shape of the eyeball & focuses light into the eye
explain eye lens
transparent/elastic convex lens which focuses light onto the retina
explain vitreous humour
transparent jelly-like substance/maintains the shape of the eyeball & focuses light onto the retina
explain retina
layer that contains photoreceptors
what is photoreceptors?
detects light & produces nerve impulses
explain yellow spot
part of retina/most sensitive to light bcuz got many photoreceptors
explain blind spot
part of retina/not sensitive to light bcuz no photoreceptors
what do rod cells do?
to detect light intensity including faint light
what do cone cells do?
to detect colors of light under bright conditions
primary colours of light?
red, green, blue
mechanism of hearing
earlobe - ear canal - eardrum - ossicles - oval window - cochlea - auditory nerve
function of earlobe?
to collect/gather sound
function of ear canal
transpeed the sound to the eardrum (middle ear)
function of eardrum
help produce & transpeed sound vibration to the ossicles
function of ossicles?
amplify/increase the sound vibration
function of oval window?
transmit the sound vibration to the cochlea
function of cochlea
convert vibration into nerve impulse
function of auditory nerve
carry nerve impulse to brain
function of eustachian tube
help balance the pressure of the middle ear
function of semicircular canals
helps balance your body
function/pathway of sensory cells for smell
mucus allows chemical substances in the air to dissolve & stimulate cells to produce nerve impulse. Sent ti brain. Brain intrepret & determine the smell
definition of papillae
the texture on the surface of the tongue. Covered by hundreds of taste buds
function/pathway of taste buds?
Saliva dissolve chemical substance in food. Will difuse into taste buds thru pores. Stimulate taste receptors to produce nerve impulse. Sent to brain to be intrepreted.
sensitivity of skin towards stimuli depends on?
number of receptors & thickness of the skin epidermis
limitations of sight
optical illusions, blind spot, cannot see very tiny objects (microorganisms) & distant objects
name 3 defects of sights?
i) short-sightedness
ii) long-sightedness
iii) astigmatism
what causes short-sightedness?
eye lens too thick & eyeball too long
where is the img fromed for short-sightedness?
image is formed on the front of the retina
short-sightedness can be corrected using?
concave lens
what causes long-sightedness
eye lens too thin & eyeball too short
where is the img formed for long-sightedness?
image formed behind the retina
how can long sightedness be corrected?
convex lens
what is astigmatism?
seeing part of an object clearer than the rest of the object
what causes astigmatism
caused by uneven curvature (surfaces) of the cornea of eye lens
how can astigmatism be corrected?
use cylindrical lens
when plp get older what happens to the eardrum?
eardrum becomes less elastic
what is the hearing range of humans (frequencies)
20Hz-20 000Hz
stimuli that plants can detect?
light,water,gravity,touch
responses of plants?
tropism & nastic movement
definition of tropism?
directional response of plants to stimuli coming from a certain direction
what is known as positive tropism?
plants that grows towards a stimulus
what is known as negative tropism?
a plant which grows away from a stimulus
definition of phototropism?
response of plants towards light
definition of hydrotropism?
response of plants towards water
definition of geotropism
rseponse of plants towards gravity
definition of thigmotropism?
response of plants towards touch
shoots will always show what tropism
positive phototropism
negative hydrotropism
negative geotropism
what tropism roots will show?
positive geotropism
positive hydrotropism
negative phototropism
what tropism will stem show?
positive thigmotropism
definition of nastic movement
response towards a stimulus such as touch but does not depend on the direction of the stimulus
why is nastic movement not a type of tropism?
nastic movement occurs more rapidly than tropism
nastic movement for mimosa serves as?
defense against strong winds and it’s enemies
Where is the eyes located in stereoscopic vision?
In the front of the head
How much is the overlap in stereoscopic vision?
Large overlap
Stereoscopic vision can be seen in what dimension?
3 dimensions (3D)
3 dimensionals images formed in the overlapping field of vision allow…
distance, size and depth of objects to be estimated accurately
stereoscopic vision helps predators to ?
to estimate the distance accuarately to help them hunt
Why is stereoscopic vision more accurate?
because of the large overlapping
sterescopic vision have a narrow or wide field of vision?
narrow field of vision
where is the eyes located for monocular vision?
at the side of the head
monocular vision have narrow or wide field of vision?
wide field of vision
how much is the overlap for monocular vision
field of vision do not overlap or overlap only slightly
what dimension is the image formed for monocular vision
2 dimensional (2D)
2D images formed in the overlapping fileds of vision prevent
the distance, size and depth of objects from being estimated accurately
wide field of vision helps animals to….
detect their enemies coming from any direction
prey and predators have what vision?
prey = monocular vision
predator = stereoscopic vision
defintion of stereophonic hearing?
stereophonic hearing is hearing using both ears
stereophonic hearing allows us to…
determine the direction/location of sound accurately
stereophonic hearing helps predators….
to determine the location of their prey
stereophonic hearing helps prey…
to determine the location of their predators and to help escape from them
the ear which is nearer to the source of sound
receives sound earlier and louder than the other ear
the difference in time and loudness of the sound received by both ears is detected by
the brain which allows to determine the direction of the source of sound
frequencies of hearing range for sea lion
450 - 50 000 Hz
frequencies of hearing range of dolphin
40 - 100 000 Hz
frequencies of hearing range of elephant
16 - 12 000 Hz
frequencies of hearing range of dog
67 - 45 000 Hz
frequencies of hearing range of bat
2 000 - 110 000 Hz
frequencies of hearing range of rat
200 - 80 000 Hz
responses of stimuli ensures….
the survival of animals on earth
response : secretion of pheromone, do what?
hormone that produce bad smell to scare enemies
sensory organ: lateral line, do what?
to determine the direction of enemy and to detect disruption of water
response: producing electric field, do what?
scare off any enemies
