Sensory Anatomy and Physiology Flashcards

Comprehensive vocabulary flashcards covering the anatomy and physiology of vision, hearing, balance, smell, taste, receptor types, and related sensory disorders.

Cornea

The clear, avascular outer covering of the eye that protects it and helps bend and focus light.

Pupil

The opening in the eye that allows light to enter.

Iris

The colored part of the eye that controls the size of the pupil.

Lens

The structure in the eye that focuses light onto the retina.

Retina

The layer at the back of the eye containing photoreceptors that converts light into nerve signals.

Sclera

The white outer protective layer of the eye.

Choroid

The layer underneath the retina containing blood vessels that nourish the eye.

Vitreous humor

A gel-like substance that presses and holds the retina against the back of the eye.

Aqueous humor

Watery fluid between the cornea and lens that helps maintain intraocular pressure and eye shape.

Rods

Photoreceptors responsible for vision in dim light and night vision that do not detect color well.

Cones

Photoreceptors that detect color and function best in bright light, consisting of red, green, and blue types.

Frequency (Sensory Perception)

A wave property that determines color in vision and pitch in hearing.

Amplitude (Sensory Perception)

A wave property that determines brightness or shade in light and volume in sound.

Myopia

Nearsightedness, a condition where close objects are clear but distant objects are blurry because light focuses in front of the retina.

Hyperopia

Farsightedness, a condition where distant objects are seen better than close ones because light focuses behind the retina.

Astigmatism

Vision disorder caused by an abnormal curvature of the cornea or lens, resulting in blurry or distorted vision.

Cataracts

A condition characterized by the clouding of the eye's lens.

Glaucoma

Increased intraocular pressure that can damage the optic nerve and cause permanent vision loss.

Macular degeneration

A condition that damages the macula, impairing central vision.

Extrinsic Eye Muscles

Six muscles controlling eye movement, consisting of four rectus muscles (superior, inferior, medial, lateral) and two oblique muscles (superior, inferior).

Looking Left (Muscle Action)

The contraction of the left lateral rectus and the right medial rectus muscles.

Pinna

The outer structure of the ear, also called the auricle, that collects sound waves.

Tympanic membrane

The eardrum, which vibrates when hit by sound waves.

Ossicles

Three small bones in the middle ear consisting of the malleus, incus, and stapes.

Malleus

The first middle ear ossicle, attached directly to the eardrum.

Incus

The middle ossicle bone located between the malleus and stapes.

Stapes

The final ossicle bone that pushes on the oval window; it is the smallest bone in the human body.

Oval window

A membrane that receives vibrations from the stapes and transmits them to the inner ear.

Eustachian tube

A canal connecting the middle ear to the back of the throat/nasal cavity that drains excess fluid from the middle ear.

Cochlea

The inner ear structure responsible for hearing, where mechanical vibrations are converted into neural signals.

Vestibule

An inner ear structure that helps detect balance and head position.

Semicircular canals

Three fluid-filled canals oriented in different planes that detect rotational and head movement for balance.

Otoconia

Tiny crystals in the inner ear, also known as otoliths, involved in sensing movement and position.

Endolymph

Fluid contained within the inner-ear vestibular system.

Organ of Corti

The structure that bundles nerve signals and transmits a combined neural signal to the auditory cortex.

Central vertigo

Vertigo originating from a problem in the central nervous system or brain.

Peripheral vertigo

Vertigo originating from a problem in the inner/middle ear or vestibular nerve.

BPPV

Benign Paroxysmal Positional Vertigo, a disorder caused by displaced otoconia/crystals in the inner ear leading to dizziness.

Epley maneuver

A therapeutic repositioning procedure designed to move displaced inner-ear crystals back to their proper location in BPPV.

Ménière’s disease

An inner ear disorder associated with vertigo, tinnitus, and excess inner-ear fluid.

Tinnitus

A perception of ringing or buzzing sound in the ears.

Odorants

Chemical compounds that stimulate smell receptors.

Olfaction

The sense of smell.

Glomerulus

An olfactory structure that receives and organizes signals from odorants.

Mitral cells

Neurons in the olfactory system that transmit smell signals to the brain.

Olfactory fatigue

A temporary inability to distinguish a particular odor after prolonged exposure to it.

Anosmia

Complete loss of the sense of smell.

Hyposmia

A reduced ability to detect smells.

Hyperosmia

An abnormally increased sensitivity to smells.

Phantosmia

An olfactory hallucination where a person smells something that is not present.

Primary Taste Modalities and Stimulants

The five basic taste modalities and their chemical stimuli: Sweet (Monosaccharides), Salty ($Na^+$), Sour ($H^+$ / acids), Bitter (Alkaloids), and Umami (Glutamate).

Capsaicin

A compound found in chili peppers that stimulates heat and burning sensory receptors, creating a spicy sensation.

Menthol

A compound that stimulates cold-sensitive receptors to produce a cool sensation.

Alkylamides

Heavy molecules that remain in the mouth and contribute to a burning sensation.

Isothiocyanates

Aerosolized chemical compounds that travel toward the back of the nose and throat.

Photoreceptors

Sensory receptors that respond to light stimulus.

Mechanoreceptors

Sensory receptors that respond to mechanical movement or pressure.

Nociceptors

Sensory receptors that respond to pain and temperature changes.

Chemoreceptors

Sensory receptors that respond to chemical stimuli, such as odorants and tastants.

Synesthesia

A neurological condition where stimulation of one sense automatically leads to an experience in another sense.

Sensory conflict

A phenomenon where the brain receives mismatching signals from different senses, causing conditions such as motion sickness.