A.3 Flashcards
Sense organs
Send a message to central nervous system and nerve impulses arriving at the brain result in sensation
Sensory cells
Send messages to certain parts of brain that control emotion and memory
Mechanoreceptors
Stimulated by mechanic force or pressure, ex touch: sensitive to strong or light pressure, in arteries sense blood pressure
Chemoreceptors
Respond to chemical substances. Ex: ph changes, adjust breathing rate, or pain receptors respond to chemical released by damaged tissue
Thermoreceptors
Respond to Temperature change found in skin
Photoreceptors
Respond to light energy, found in our eyes
Rod cells
- More sensitive to light, function in dim light,
- one type used in retina that absorbs all wavelengths,
- the impulse from a group of rod cells pass to a single nerve fibre in the optic nerve.
Cone cells
- less sensitive to light, function in bright light
- 3 types found in retina sensitive to red, blue, green
- Impulse from a single cone cell passes to a single nerve fibre in optic nerve
Bipolar neurones
Cells in retina that carry impulses from rod/cone cell
To a ganglion cell
Ganglion cell
Synapses with bipolar neurones to send impulses to the brain via optic nerve
Dichromatic vision
Defect only uses 2 classes of cones either red blue or green blue, inherited by sex linked trait
Sound waves
Successive vibrations of air molecules caught by the outer ear
Hair cells ( cochlea)
Have stereocilia that stick out of hair cells and detect sounds of a specific wavelength. Sterocilia bend back and forth causes an internal change in hair cell produces an electrical impulse carried to the auditory nerve
Processing of sound
In the auditory nerve of cerbral cortex
Hair cells (semicircular canal)
We have 3 semi circular canals in each ear controls equilibrium. Movement of fluid over hair cells detects rotational movement of head. Hair cells are sensory receptors that send messages to vestibular nerve, relayed to brain tells us our position
