A&P Special Senses

Vocabulary flashcards related to special senses, covering olfaction, gustation, equilibrium, hearing, and vision.

Olfaction (olfactory)

The sense of smell.

Gustation (gustatory)

The sense of taste.

Olfactory epithelium

Superior nasal cavity down to the superior nasal concha, containing olfactory receptor cells.

Olfactory receptor cells

Neural soma in nasal epithelium; bipolar nerves that detect odorants.

Olfactory cilia

Dendrite end of neuron; Chemoreceptor that detects odorants.

Chemoreceptor

Detect odorants.

Transduction (olfaction)

Open Na+ channels to trigger action potential.

Olfactory gland (Bowman gland)

Produce mucus in the olfactory epithelium.

Olfactory bulb

Masses of grey matter where the first synapse between PNS and CNS occurs.

Olfactory tract

Connect olfactory bulb with olfactory cortex, hypothalamus and limbic system.

Chemoreceptor (gustation)

Gustatory receptor, detects chemicals.

Papillae of tongue

Raised areas on tongue where taste buds are located.

Circumvallate papillae

Large papillae (8-12 on tongue) each having 100s of taste buds.

Fungiform papillae

Smaller papillae mostly on the tip/side of the tongue; each has ~5 taste buds.

Foliate papillae

Short folds on lateral/posterior of tongue.

Filiform papillae

Papillae on anterior 2/3 of tongue with NO taste buds.

Gustatory hair

Exits through Taste Pore to detect Tastants.

Transduction (salt and sour)

Open Na+ channels (gustation).

Transduction (sweet, bitter, and umami)

Activate G-proteins (intracellular).

External Ear

Outside of tympanic membrane.

Middle Ear

Behind tympanic membrane.

Inner Ear

Sensory; cochlea and vestibule within the bony labyrinth.

Bony Labyrinth

The bone shell surrounding the inner ear parts (membranous labyrinth).

Bony Labyrinth parts

Semicircular canals, vestibule, cochlea

Membranous labyrinth

Inside Bony Labyrinth.

Vestibule

Middle section between semicircular canals and cochlea; static equilibrium.

Saccule

Linear acceleration.

Utricle

Linear acceleration (larger of the two).

Semicircular canals/ducts

Dynamic equilibrium.

Ampulla

Enlarged areas at base of semicircular canals/ducts.

Dynamic equilibrium

Rotational movement.

Static equilibrium

Linear movement.

Ampulla (equilibrium)

Dilated area at base of canals; contains receptors.

Crista

Inside Ampulla, contains receptors.

Supporting cells (equilibrium)

Structure where sensory nerve connects to hair cells.

Hair cells (equilibrium)

Cells in supporting structure with hair bundles that protrude into cupola; for transduction.

Cupula

Slightly thicker than endolymph; moved by endolymph with motion.

Otolithic membrane

Gelatinous material with stones (stataconia) on the surface.

Otoliths

Otolithic membrane + stataconia.

Cochlea

Hearing.

Cochlea sections

Cochlear duct, scala vestibule, scala tympani.

cochlear duct

Middle area

Scala vestibule

To oval window

Scala tympani

To round window

Tectorial membrane

Moves with changes in perilymph.

Hair bundle (cochlea)

Touches tectorial membrane.

Hair cell (cochlea)

Transduction occurs here; connected to nerve fibers.

Vestibular branch

Equilibrium

Cochlear branch

Hearing

Accessory Structures (eye)

Eyelids, eye lashes/eye brows, lacrimal apparatus, extrinsic eye muscles.

levator palpebrae superioris

muscle to raise upper eyelid

orbicularis oculi

round muscle around the eye that closes eyelid

conjunctiva

thin mucosal membrane lining the palpebra

lacrimal gland

laterally positioned superior to each eye bilaterally secretes lacrimal fluid (tears).

lacrimal puncta (pl.) punctum (sing.)

orifice near medial commissure, lacrimal fluid enters

nasolacrimal duct

connect lacrimal sac to nasal cavity for lacrimal fluid drainage

palpebrae fissure

gap between superior and inferior eyelids

lateral canthus (commissure)

lateral point where superior and inferior eyelids meet

medial canthus (commissure)

medial point where superior and inferior eyelids meet

lacrimal caruncle

near medial canthus: produces thick mucus

extrinsic eye muscles

superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, inferior oblique

Eyeball layers

Fibrous tunic, vascular tunic, neural tunic

superficial fibrous tunic avascular sclera

white of the eye

cornea

clear anterior aspect of the fibrous tunic

vascular tunic parts

choroid, ciliary body, iris

choroid

posterior vascular tunic nutrient rich, perfuses retina, dark, absorbs light

ciliary body

anterior vascular tunic continuous with choroid

ciliary process

secretes aqueous humor

canal of Schlemm

collecting channel for drainage of aqueous humor

ciliary muscle

attached to lens via ciliary (suspensory) ligaments changes shape of lens to focus

iris

colored portion: melanin controls aperture of pupil

circular muscle

closes pupil (constriction)

radial muscle

opens pupil (dilation)

neural tunic retina

inner layer posterior ¾ of eye

optic disc blind spot

CN II innervation

central fovea fovea centralis

all cones greatest visual acuity/resolution in an area called the macula lutea (yellow spot)

pigmented layer (retina)

between choroid and retina also absorbs stray light

neural layer (retina)

photoreceptors: rods: NOT color cones: color

Lens

clear, refracts light to focus on the central fovea attached via the suspensory ligaments

vitreous cavity

posterior to lens filled with vitreous body/humor

anterior cavity

filled with aqueous humor

anterior chamber

between cornea and iris

posterior chamber

behind iris, adjacent/anterior to lens

refraction

bending of light as it passes through a substances of differing density

Accommodation

increased convexity of lens to view objects up close

emmetropic

normal vision: clear vision at 20’

myopia

near sighted; focal point in front of the retina

hyperopia

far sighted; focal point behind the retina

astigmatism

irregular curvature of retina or lens; partial image blurring

Convergence

both eyes will direct and focus on same object

Rhodopsin

color pigment responsible for transduction of light

opsin

protein containing

retinal

pigment derived from vit A

Process (photoreceptors/photopigments)

light hits rhodopsin, retinal: normally curved: straightens out, this causes a change in membrane permeability, Na+ floods in: creates graded/action potential (transduction)

bleaching

rhodopsin separates into opsin and retinal