Senses Flashcards
If the organ is the eye, what is the stimulus and the receptor?
Stimulus - Light
Receptor - Photoreceptors in the retina
If the organ is the ear , what is the stimulus and the receptor?
Stimulus - sound
Receptor - cilia/hairs in cochlea
If the organ is the skin, what is the stimulus and the receptor?
Stimulus - Touch/temperature
Receptor - Thermoreceptors /Mechanoreceptors
If the organ is the nose, what is the stimulus and the receptor?
Stimulus - Smell
Receptor - Chemoreceptor (odours)
If the organ is the tongue, what is the stimulus and the receptor?
Stimulus - Taste
Receptor - Taste buds
Iris
Helps control the amount of light entering the eye
How can the skin and tongue detect stimuli and send information to the brain for processing?
The skin had mechanoreceptors and thermoreceptors, and the tongues chemoreceptors (taste buds) these convert the stimulus to mere impulses which travel to the brain along sensory neurons
2 examples of reflex responses:
Blinking & Knee jerking
Pupil
Black part of the eye. This is an opening that lets light in
Lens
Focuses light onto the retina
Blind spot
In this area there are no light-sensitive cells so this part of your retina can’t see.
Sclera
The sclera is the white part of your eye. It’s a protective covering that wraps over most of your eyeball. It extends from the cornea at the front of your eye to the optic nerve in the back.
Optic Nerve
Transfers electrical impulses from the retina for the brain for decoding
Retina
Contains photosensitive rod and cone cells to produce electrical impulses from light stimuli
In an investigation of the effects of caffeine, what is the independent variable?
Caffeine vs no Caffeine
In an investigation of the effects of caffeine, what is the dependent variable?
The reaction speed (which can be calculated from reaction distance)
In an investigation of the effects of caffeine, what would you hypothesise the result seen between a test with caffeine and test without?
Reaction speeds would be faster (smaller number) with caffeine as it is a stimulant
How can you get more accurate and reliable data in an investigation in reaction times in male and females?
Test it with more males/females (not just 2), and repeat the test multiple times (per person) for reliability
How does the reflex arc lead to a person moving their hand away from a hot flame?
- The hot flame stimulus is detected by receptors in the skin.
- A nerve impulse is then sent to the sensory neuron
- to the spinal cord. Here it passes the synapse to a relay neuron
- in the spina cord and quickly sent across another synapse to a motor neuron
5.which interacts with an effector - muscle to move the arm
What happens to the lens when focusing on a closer object?
It gets fatter to refract the light rays, so the ciliary muscles contract, and the suspensory ligaments relax
What happens to the lens when focusing on a far object?
It gets thinner to refract the light rays more
What happens in the pupil reflex to protect the eye from bright light
The pupils gets smaller to prevent as much light entering the eye. Radial muscles relax, circular muscles contract.
Nervous pathaway (stimulus to response)
- Stimulus
- Receptor (pressure receptors)
- Sensory neuron
- Synapse
- Relay neuron
- Synapse
- Motor Neuron
- Effector
- Response
