Sensory Reception (exam) Flashcards
What are sensory receptors?
Cells or nerve endings sensitive to stimuli which translate messages into impulses in sensory neurons.
What is a sensation?
The cerebral cortex’s response to information.
What is perception?
How the cerebral cortex interprets impulses.
What is sensory adaptation? Where would it occur?
The brain’s method of filtering out unnecessary stimuli. It would occur in the thalamus.
What are the 4 types of receptors?
Chemoreceptors, mechanoreceptors, thermoreceptors and photoreceptors.
What is the Sclera? What is it’s purpose?
The outermost layer of the eye. It provides the eye with protection and support.
Where is the cornea? What is it? What is it’s purpose?
The cornea is a clear section of the sclera. It is the portion of the eye where light enters.
Where does the cornea get nutrients from?
Since the cornea has no blood vessels, it receives it’s nutrients and oxygen from the atmosphere with tears.
Where is the choroid? What is it’s purpose?
The choroid in the intermediate layer of the eye. It is pigmented to prevent light from scattering in the eye, absorbing stray light rays.
Where is the iris? What is it?
The iris is in front of the choroid at the front of the eye. It regulates the amount of light entering the eye. Everyone has a unique iris.
Where is the pupil? What does it do?
The pupil is in the middle of the iris. It contracts and expands to allow more or less light into the eye.
Where is the Lens? What does it do?
The lens is found behind the choroid. It changes shape to focus images at the retina.
How does the lens change shape?
Ciliary muscles in the eye contract the lens to make it rounder, while suspensory ligaments hold ciliary muscles in place and tighten to flatten the lens.
Where is the retina? What does it contain?
The retina is the innermost layer of the eye. It contains rods and cones which are the photoreceptors of the eye.
What are rods sensitive to?
Rods are sensitive to light and dark.
What are cones sensitive to?
Cones are sensitive to colour. They are focused in the middle of the retina, in the fovea centralis.
Where is the macula? What is it?
The macula is in the Center of the retina. It contains the most cones in the eye. It is also referred to as the fovea centralis.
Where does the optic nerve connect to the eye?
It connects at a point in the retina called the blind spot.
Where is the aqueous humour? What is it’s purpose?
The aqueous humour is found between the lens and cornea. It drains daily and provides surrounding cells with nutrients while maintaining the eyes shape
Where is the vitreous humour? What is it’s purpose? What is it’s consistency?
The vitrious humour is found behind the lens in the major part of the eye. It maintains the eyes shape and supports surrounding cells. It is jelly-like, 99% water and 1% collagen. It never drains and is responsible for eye floaters.
What are eye floaters?
Eye floaters are neutrally bouyant clumps of collagen that form in the eye after many years.
What does image initially look like when it enters your eye?
The image is initially upside down and inverted.
What is accommodation?
Accommodation is the eye changing the shape of its lens to focus images.
What does the lens do when focusing on near objects?
The lens becomes rounder as the ciliary muscles contract to increase the curvature.
