The Senses Flashcards
Give the function of the semicircular canals.
Balance
In which part of the ear are nerve impulses generated?
Cochlea
In what part of the eye are nerve impulses generated?
Retina
Suggest one way by which the ear may be protected.
Wearing ear protection in areas of excessive noise
Explain how a corrective measure for a named defect of hearing works
Glue ear is a hearing disorder caused by a build-up of mucus in the middle ear, can be corrected by fitting grommets.
The grommets work by allowing air into the middle ear, which then forces the mucus down the Eustachian tube
Give the function of the lens.
Focuses the image onto retina.
Give function of vitreous humour.
Gives shape to the eyeball.
Outline role of vision of the suspensory ligaments.r
-are connected to lens and ciliary muscle.
When muscle contracts, the ligaments are relaxed and lens is round and fat.
When muscles relaxes, the ligaments are pulled tight and the lens is stretched into a long thin shape.
Outline the roles of cones.
Cones are light receptors located in the Retina.
Cones detect colour and work in bright light.
Most of the cones are located at the fovea, the region of sharpest vision.
Outline the role of the optic nerve.
Connects the eye with the brain.
It contains millions of axons, which carry impulsesu from retina to the brain.
Outline the role of the brain in vision.
optic nerve takes impulses from the retina to the area of the brain associated with vision.
This area is located in the cerebrum at the very back of the brain.
Explain how the iris works.
Iris regulates the amount of light entering the eye.
In bright light, the iris changes shape to reduce the size of the pupil, in dim light, the iris shortens to dilate the pupil and allow more light into the eye.
Give the function of the Eustachian tube.
It equalises pressure in both sides of the eardrum
