Either large, complex sensory organs or localized clusters of receptors.
The eye include the extrinsic muscles, eyelids, conjunctiva, and lacrimal apparatus.
Meet the medial and lateral corners of the eye.
Modified sebaceous glands associated with the eyelid edges.
Lines the eyelids and covers part of the outer surface of the eyeball.
Inflammation of the conjunctiva.
Infectious form caused by bacteria or viruses, is highly contagious.
consists of the lacrimal gland and a number of ducts that drain the lacrimal secretions into the nasal cavity.
Located above the lateral end of each eye.
Empties into the nasal cavity.
An enzyme that destroys bacteria.
Extrinsic Eye Muscle
Attached to the outer surface of each eye.
A hollow sphere that is composed of three layers.
Outer most layer, consists of the protective sclera and transparent cornea.
Thick, glistening white connective tissue, is seen anteriorly as the "white of the eye."
Well supplied of nerve endings, most exposed part of the eye, and it is very vulnerable to damage.
The middle layer of the eyeball, has three distinguishable regions.
Most posterior in the vascular layer, is a blood rich nutritive tunic that contains a dark pigment.
Moving anteriorly, the choroid is modified to form two smooth muscle structures.
The lens is attached by a suspensory ligament.
Responsible for controlling the diameter and size of the pupil.
Light passes through it .
The delicate two layered retina.
Extends anteriorly only to the ciliary body.
Composed of pigmented cells that, like those of the choroid, absorb light and prevent light from scattering inside they eye.
Contains millions of receptor cells.
Allow us to see in grey tones and dim light, and they provide for our peripheral vision.
Anything that interferes with rod function hinders our ability to see at night.
Allow us to see the details of our world in color under bright light conditions.
Nerve impulses that are transmitted to the optic cortex.
The transparent inner neural layer of the retina contains millions of receptor cells, the rods and cones,
Optic Disk/ Blind Spot
The site where the optic nerve leaves leaves the eyeball.
A tiny pit that contains only cones.
Point of sharp vision, and anything we wish to view critically is focused on the fovea centralis.
Whereas lack of one cone type leads to partial color blindness.
Light entering the eye is focused on the retina.
Cause vision to become hazy and distorted, and they eventually cause blindness to affect they eye.
A clear watery fluid.
Pressure withing the eye may increase to dangerous levels and compress the delicate retina and optic nerve.
Vessels at the posterior wall of the eye to be viewed and examined.
When light passes from one substance to another substance that has a different density, its speed changes and its rays are bent.
This ability of the eye to focus specifically for close objects.
The fibers from the medial side of each eye cross over to the opposite side of the brain.
The fiber tracts that result .
Loss of same side of the visual field of both eyes, which results from damage to the visual cortex on one side only.
The reflexive movement of the eye medially when we view close objects.
"Two-eyed vision" provides for depth perception. Our visual cortex fuses the two slightly different images delivered by the two eyes.
Unequal curvatures in different parts of the cornea or lens.
When the eyes are suddenly exposed to bright light, the pupils immediately constrict.
Receptors that respond to such physical forces.
External Acoustic Meatus
A short, narrow chamber carved into the temporal bone of the skull.
The shell-shaped structure surrounding the auditory canal opening.
The skin-lined walls of the skull which secret a waxy yellow.
Provides a sticky trap for foreign bodies and repels insects.
Tympanic Membrane/ Eardrum
Sound waves entering the auditory canal, cause the eardrum to vibrate.
Middle Ear/ Tympanic Cavity
Small air-filled, mucosa-lined cavity within the temporal bone.
Flanked literally by the eardrum and medially by a bony wall with two openings.
Pharyngotympanic Tube/ Auditory
Runs obliquely downward to link the middle ear cavity with the throat, and the mucosae lining the two regions are continuous.
Inflammation of the middle ear.
Transmit the vibratory motion of the eardrum to the fluids of the inner ear.
Transfers the vibration to the anvil.
Passes the vibration on to the stirrup
Presses on the oval window of the inner ear.
Osseous/ Bony Labyrinth
Located deep within the temporal bone behind the eye socket.
Situated between the semicircular canals and the cochlea.
A plasmalike fluid that fills the bony labyrinth.
A system of membrane sacs that more or less follows the shape of the bony labyrinth.
The membranous labyrinth itself contains a thicker fluid.
The equilibrium receptors of the inner ear.
Within the membrane sacs of the vestibule are receptors.
Otolithic Hair Membrane
A jellylike mass studded with otoliths.
Tiny stones made of calcium salts.
Lens that possesses at least one surface that curves inwards.
Converge the light rays before they enter the eye.
The spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations.
Three fluid-filled bony channels in the inner ear. They are situated at right angles to each other and provide information about orientation to the brain to help maintain balance.
A form of equilibrium that occurs when an object is at rest. Static refers to the object being motionless while equilibrium refers to the object either having no net forces acting upon it or having all of its net forces balanced.
Stimulates the hair cells, and impulses are transmitted up the vestibular nerve to the cerebellum.
Found in the semicircular canals, respond to angular or rotatory movements of the head rather than to straight-line movements.
A swollen region at the base of each membranous semicircular canal.
Tuft of hair cells covered with a gelatinous cup.
The endolymph-containing membranous labyrinth of the cochlea.
Containing the hearing receptors.
The hair cells transmit impulses to the auditory cortex in the temporal lobe.
Hearing loss of any degree.
Something interferes with the conduction of sound vibrations to the fluids of the inner ear.
Fusion of the ossicles.
Degeneration or damage to the receptor cells in the spiral organ of corti.
Progressive deafness occurs, Exact cause is unknown.
A sensation of spinning, it is so severe that they cannot stand without discomfort.
The receptors for taste and olfaction, they respond to chemical solutions.
Receptors for the sense of smell, occupy a postage stamp-sized area in the roof of each nasal cavity.
Olfactory Receptor Cells
Neurons equipped with olfactory hairs.
Long cilia that protrude from the nasal epithelium and are continuously bathed by a layer of mucus.
Bundled axons of olfactory neurons that collectively make up the olfactory nerve.
Conducts impulses to the olfactory cortex of the brain.
Loss of chemical senses have olfactory disorders.
Specific receptors for the sense of taste.
Small peglike projections.
The specific cells that respond to chemicals dissolved in the saliva.
The ear ossicles fuse.
Papillae on the upper surface of the tongue.
Opening of a taste bud on the surface of the oral mucosa.
Each of the ninth of cranial nerves, supplying the tongue and pharynx.
Each of the tenth pair of cranial nerves, supplying the heart, lungs, upper digestive tract, and other organs of the chest and abdomen.