Past Exam Questions Flashcards
What fluid fills the rear chamber of the human eye?
Vitreous humour
What is the function of the vitreous humour?
A viscous solution which supports the eye by exerting an outward pressure on the eyeball
What are the two types of light receptor cells found in the eye?
Rods
Cones
What are the roles of rods and cones?
Cones detect colour
Rods detect black and white light
What is the transparent covering in front of the cornea?
Conjunctiva
What is the role of the conjunctiva in the eye?
A thin membrane that protects the sclera from infection
Suggest an advantage to humans of having two eyes
It allows for depth perception and an increased visual field
It allows allows for the blind spot in one eye to be seen using the opposite eye and vice-versa
Name a disorder of the ear?
Glue ear
Name a corrective measure for glue ear?
Grommets are inserted into the eardrum which allow air into the middle ear and forced fluid down the Eustachian tube.
Outline the function of the pinna
The pinna helps to collect and channel vibrations into the auditory canal
To which part of the body does the Eustachian tube link the ear?
Throat/pharynx
What is the role of the Eustachian tube?
Equalises pressure on either side of the eardrum thus preventing damage to the eardrum caused by differences in pressure between the outer and inner ear.
Name another part of the ear that has a function similar to that of the stirrup
Hammer or anvil
Suggest why there are three semi-circular canals in each ear
To control balance on three dimensions/axes
Name the part of the eye that has a corresponding function to the cochlea of the ear.
Retina
Explain how the retina of the eye has a corresponding function to the cochlea of the ear
Both contain receptors and generate impulses which they send to the brain
Name the structure that determines the diameter of the pupil
Iris
Why is there a mechanism for changing the diameter of the pupil?
To control the amount of light that enters the eye
To prevent too much light entering the eye
Name two parts of the eye which have curved surfaces?
Cornea
Lens
How does the curvature of the eye contribute to its functioning?
It allows for the focusing of light and the refraction of light
Suggest a benefit for herbivores having eyes located at the sides of the skull
To give them a wider field of vision to detect predators
Suggest a benefit for carnivores having eyes located close together at the front of the skull?
To better focus on prey
For better judgment of distance
In what part of the eye are nerve impulses generated?
Retina
Suggest one way by which the ear may be protected
Wax or ear protection
Outline the roles of sensory ligaments in vision
Hold the lens in place and is involved in the changing of the lens shape
Outline the role of cones in vision
Detect colour
Outline the role of the optic nerve in vision
Brings impulses from the retina to the brain
Outline the role of the brain in vision
Receives information from the brain and then interprets it
How does the iris work?
The iris is the coloured, muscular part of the eye which controls the amount of light entering the eye
The pupil is the opening in the iris and its size depends on the amount of light which the iris allows to let into the eye
i.e. the size of the pupil will be small when there is too much light getting into the eye and the pupil will be large when there is a small amount of light getting into the eye
