Biol 208: Chapter 15 - The Special Senses

Vocabulary practice flashcards covering the key structures, definitions, and functions of the special senses (eye, olfaction, taste, and ear) from Biol 208 lecture notes.

Anatomy

The study of form, shape, location, and connections of biological structures ('what?' and 'where?').

Physiology

The study of function and how biological structures work to support life ('how?' and 'why?').

Eyebrows

Short, coarse hairs that overlay the supraorbital margins of the skull to shade eyes from sunlight and prevent sweat from dropping into eyes.

Eyelids (palpebrae)

Structures that protect the front of the eye.

Palpebral fissure

The slit between the two eyelids.

Medial and lateral commissures

The corners of the eye where the two eyelids come together.

Lacrimal caruncle

A structure located at the medial corner of the eye that contains sebaceous and sweat glands.

Orbicularis oculi muscle

The muscle that controls the closing of the eyelids.

Levator palpebrae superioris muscle

The muscle that controls the opening of the eye.

Conjunctiva

A thin, protective mucous membrane lining the eyelids and covering the anterior surface of the eye itself, which produces lubricating mucus.

Conjunctival sac

The space between the eye and the eyelids.

Conjunctivitis

Inflammation of the conjunctiva resulting in reddened, irritated eyes, often called pinkeye.

Lacrimal apparatus

The system consisting of the lacrimal gland and the ducts that drain lacrimal secretions into the nasal cavity.

Lacrimal punctum

Two small openings that lead from the eye to the lacrimal canaliculi.

Extrinsic eye muscles

Six muscles that control the movement of the eye, maintain its shape, and hold it in place.

Rectus muscles

Four extrinsic eye muscles (Lateral, Medial, Superior, Inferior) that all originate from the common tendinous ring.

Oblique muscles

Two extrinsic eye muscles (Superior and Inferior) that elevate or depress the eye and turn it laterally.

Ciliary body

An intrinsic eye muscle controlled by the autonomic nervous system that changes the shape of the lens to focus on objects at varying distances.

Iris

An intrinsic eye muscle controlled by the autonomic nervous system that adjusts the diameter of the pupil to control the amount of light entering.

Fibrous layer

The outer connective tissue layer of the eye composed of the sclera and cornea.

Sclera

Part of the fibrous layer that protects and shapes the eyeball and provides an anchoring site for the extrinsic eye muscles.

Cornea

The transparent portion of the fibrous layer that allows light to enter, contains pain receptors, lacks blood vessels, and can be transplanted without risk of rejection.

Vascular layer

The pigmented middle layer of the eye consisting of the choroid, ciliary body, and iris.

Choroid

Part of the vascular layer that contains blood vessels that nourish the eye and brown pigment that absorbs light.

Retina

The inner layer of the eye that develops from an extension of the brain and contains photoreceptors that convert light energy.

Rods

Photoreceptors in the neural layer of the retina responsible for dim-light and peripheral vision.

Cones

Photoreceptors in the neural layer of the retina responsible for bright light and color vision.

Aqueous humor

Fluid filling the anterior segment of the eye that is continuously made and drained.

Vitreous humor

Fluid filling the posterior segment of the eye that transmits light, supports eye layers, maintains intraocular pressure, and is formed before birth.

Lens

A transparent, flexible structure that can change shape to focus light on the retina.

Cataract

A clouding of the lens that causes blurry vision.

Olfactory epithelium

Specialized tissue in the roof of the nasal cavity made of olfactory sensory neurons and columnar supporting cells that detects smells.

Taste buds

Sensory organs for taste containing gustatory epithelial cells, located primarily on the tongue as well as the soft palate, cheeks, pharynx, and epiglottis.

Fungiform papillae

Peg-like projections of the tongue mucosa scattered over the tongue surface.

Vallate papillae

8 to 12 peg-like projections arranged in a V shape at the back of the tongue.

Foliate papillae

Peg-like projections located laterally on the tongue.

Auricle (pinna)

The shell-shaped cartilaginous projection of the external ear that funnels sound into the external acoustic meatus.

External acoustic meatus

The canal extending from the auricle to the eardrum, containing ceruminous glands that secrete earwax.

Tympanic membrane

A thin, translucent tissue membrane covered by skin that forms the boundary between the external and middle ears and vibrates when hit by sound waves.

Pharyngotympanic tube

A tube connecting the middle ear cavity to the back of the throat that opens during swallowing or yawning to equalize pressure.

Auditory ossicles

The three smallest bones in the body (malleus, incus, and stapes) located in the middle ear that transfer vibratory motion from the tympanic membrane to the inner ear.

Bony labyrinth

A system of channels winding through bone in the internal ear, filled with perilymph.

Membranous labyrinth

A continuous series of sacs and ducts suspended within perilymph inside the bony labyrinth, filled with endolymph.

Vestibule

A region of the internal ear responsible for sensing gravity and linear movement.

Semicircular canals

A region of the internal ear responsible for sensing rotational movement.

Cochlea

A region of the internal ear responsible for hearing.