Special Senses Flashcards
Two forms of sensory receptors (nerve endings)
Free nerve ending or nerve ending surrounded by a capsule
What do free nerve endings respond to
Cold, heat, vibration, pressure, touch, itch, pain
Pathway of light in the eye
Enters posterior chamber through the black pupil, passes through the lens, then traverses the vitreous
What is the retina
Light sensitive part of the eye, converts light energy into electrical nerve impulses
Where is most vision restricted to
Small area called the macula lutea
Where is detailed vision restricted to
Fovea centralis
What are cone photo receptor cells mainly used for
Mainly for daylight (photopic) vision and colour vision
What are rods used for
Low light (scotopic) vision and peripheral vision`
Rods vs Cone nerve endings difference
Rods share the same nerve fibre while each cone in the fovea has its own nerve connection to the brain
Where is the blind spot on the retina
Where there are no rods or cones and the optic nerve is formed at the optic disc
What is accommodation in relation to the eye
ability to alter out eye’s lens so that it can focus on objects at any distance away
What are myopia and hyperopia
Near sightedness and longsighted ness
What is astigmatism
Cornea is unevenly curved
What is presbyopia
Old-age vision, caused by lens losing its elasticity
What is age-related macular degeneration
Blurred area near the centre of vision
