a&p leture exam 5 terms

Olfactory Epithelium

Tissue in nasal cavity containing smell receptors.

Olfactory Neurons

Bipolar neurons that detect odorants and regenerate.

Glomeruli

Synaptic regions in olfactory bulb organizing receptor input.

Mitral Cells

Relay and refine olfactory signals to cortex.

Taste Buds

Structures containing taste receptor cells.

Gustatory Cells

Taste receptors that release neurotransmitters.

Five Tastes

Sweet, sour, salty, bitter, umami.

Cranial Nerves (Taste)

VII, IX, X transmit taste signals.

Gustatory Pathway

Medulla → thalamus → cortex.

Refraction

Bending of light entering eye.

Lens

Adjusts shape for focusing.

Accommodation

Lens shape change for near vision.

Rods

Dim light, low acuity vision.

Cones

Color and high acuity vision.

Phototransduction

Light converted to electrical signal.

Rhodopsin

Light-sensitive pigment in rods.

Retinal

Vitamin A derivative that changes shape with light.

Optic Chiasma

Crossing of visual pathways.

Primary Visual Cortex

Processes visual information.

Dark State

cGMP keeps Na+ channels open causing depolarization.

Light Activation

Light converts 11-cis retinal to all-trans retinal.

Transducin Activation

Activates PDE to break down cGMP.

Channel Closure

Reduced cGMP closes Na+ channels.

Hyperpolarization

Decreased neurotransmitter release signals vision.

Bipolar Activation

Reduced inhibition depolarizes bipolar cells.

Ganglion Cells

Generate action potentials to brain.

Sound Waves

Pressure waves created by vibration.

Frequency

Determines pitch.

Amplitude

Determines loudness.

Tympanic Membrane

Vibrates with sound.

Ossicles

Amplify vibrations.

Basilar Membrane

Frequency-specific vibration site.

Hair Cells

Convert mechanical movement to signals.

Resonance

Basilar membrane vibrates by frequency.

Stereocilia Deflection

Movement opens ion channels.

K+ Influx

Depolarizes hair cells.

Neurotransmitter Release

Activates cochlear nerve.

Signal Pathway

Cochlear nuclei → thalamus → auditory cortex.

Pitch Coding

Based on location of activation.

Loudness Coding

Based on AP frequency.

Maculae

Detect linear acceleration.

Crista Ampullaris

Detect rotational movement.

Otoliths

Add weight to detect gravity.

Endolymph Movement

Bends hair cells.

Vestibular Nerve

Sends balance information.

Myopia

Image forms in front of retina.

Hyperopia

Image forms behind retina.

Astigmatism

Uneven curvature of eye.

Nyctalopia

Night blindness due to rod dysfunction.

Sensorineural Deafness

Damage to hair cells or nerves.

Conduction Deafness

Impaired sound transmission.

Tinnitus

Ringing without stimulus.

Meniere’s Syndrome

Inner ear disorder causing vertigo.