Stimuli and Response (Topic 6A) Flashcards
what are the two types of responses of animals
taxic response
kinetic response
a taxic response is…
directional movement
a kinetic response is…
non directional movement
a positive tropism is when a plant…
positive tropism
a negative tropism is when a plant…
grows away from stimulus
the tropism associated with light is called…
photostropism
the tropism associated with gravity is called…
gravitopism
what is the chemical associated with tropisms?
auxin
how does auxin causes cell elongation?
loosens cell walls
auxin in ____ concentrations _____ growth in roots
high
inhibits
auxin _____ growth in shoots
stimulates
Auxin is also referred to as
IAA
Response to light:
IAA moves to the _____ side of the shoot, cells elongate and grow ____ _____
shaded
towards light
Response to light:
IAA moves to the _____ side of the roots, cell growth is inhibited and grow ____ from _____
shaded
away
light
Response to gravity:
IAA moves to the _____ side of the shoot and plant grows upwards
lower
Response to gravity:
IAA moves to the _____ side of the root, growth is _____ and plant grows downwards
lower
inhibited
receptors…
detect stimuli
effectors….
bring about response to stimuli
how does an impulse travel to an effector to cause a response
- stimulus
- receptor
- sensory neurone
- co-ordinator (brain)
5.motor neurone - effector
- response
simple reflexes are…
rapid and involuntary
simple reflexes go through the….
spinal cord
give the pathway of an impulse through a reflex arc
- stimulus
- receptors
- sensory neurone
- CNS
- motor neurone
- effectors
pacinian corpuscle detect …..
chemical stimuli
pacinian corpuscle are _______ found in your skin
mechanoreceptors
pacinian corpuscles contain a…
sensory nerve ending that is wrapped in layers of connective tissue lamellae
when a pacinian corpuscle is stimulated…
lamella are deformed and press on sensory nerve ending
when sensory nerve endings are pressed…
its cell membrane stretches, deforming the stretch mediated sodium ion channels
when stretch mediated sodium ion channels open…
creating….
the sodium ions diffuse into the cell
creating generator potential
when the generator potential reaches a threshold….
it triggers an action potential
sensory reception is
function is sense organs
sensory perception is…
making sense of information from receptors
what are the two types of photoreceptors in the eye?
rods and cones
where are photoreceptors found in the eye?
back of the retina
what is the photosynthetic pigment called that is involved with rods?
rhodopsin
what is the photosynthetic pigment involved with cones?
iodopsin
rods give information in….
black and white
where are rods located?
in the peripheral of the retina
how many rods connect to a bipolar neurone?
many
rods have ____ sensitivity to light
high
rods have ___ visual acuity
low
why do rods have low visual acuity?
because many rods connect to one BP neurone
where does the bipolar neurone take the impulse to?
the brain
cones give information in….
colour
cones are located in the…
fovea
how many cones connect to one bipolar neurone?
1
cones have ___ visual acuity
high
what kind of light do rods work best in?
dim light
what kind of light do cones work best in?
bright
how do cones provide colour information?
different types of cones respond to different wavelengths of light
cones have ___ sensitivity to light
low
what is the average resting heart rate?
72bpm
the sympathetic nervous system is responsible for…
increasing heart rate
and controls HR during exercise
the parasympathetic nervous system is responsible for…
decreasing heart rate
and controls heart rate at rest
what are the two centres responsible for heart rate in the medulla oblongata?
cardioinhibitory
cardioacceleratory
the cardioacceleratory centre ____ HR
increases
the cardioacceloratory centre ____ HR
increases
the cardioinhibatory and cardioacceleratory centre connect to the…
SA node
baroreceptors detect…
changes in blood pressure
chemoreceptors detect..
changes in pH
sympathetic neurone releases
noradrenaline
parasympathetic neurone releases…
acetylcholine
