Ch 50 Pt 2 Flashcards
Organ of Corti basilar membrane
Vibrates and pushes the hair cells against the tectorial membrane causing them to bend
Organ of Corti mechanosensitive channels
In the hair cells depolarize them
Information is carried by the ear to the auditory nerve
Each area along the basilar membrane has hair cells sensitive to ____ specific frequency of sound wave
1
Tonotopic organization
Cells respond to particular frequency
Vestibular System
Balance, equilibrium, posture, head, body, eye movement
Semicircular canals
3 distinct planes
Head rotation
Saccule and Utricle
Detect changes in head angle, gravity, linear acceleration
Motion sickness
Disruption between vestibular and visual systems
Chemical senses
Gustafson and olfaction
Taste bud
~100 taste receptor cells
Microvilli increase surface area
Taste transduction
GPCR process (bitter, sweet, umami) Inhibit ion channels (sour) Activate ion channels (salt and sour)
Taste stimuli cause
Membrane depolarization and rise in intracellular Ca2+
Smell is the only sensory receptor to
Directly make first synapse in the brain
Olfactory neurons have
High intracellular Cl
Depolarization
Opening of Cl channel
Cornea
Initial fixed lens
Pupil
Hole that allows light in (diameter determined by iris)
Lens
Focuses light onto the back of the eye
Retina
Phototransduction
Ganglion, interneuron, photoreceptors
Accommodation
Lens changes shape to maintain focus
Contraction and relaxation of ciliary muscles alters lens shape
Hyperopia
Farsighted
Focal point behind retina
Myopia
Nearsighted
Focal point in front of retina
Presbyopia
Loss of lens accommodation (aging)
Astigmatism
Imperfect cornea shape (2 focal points)