Chapter 15: Special Senses Flashcards
only major sense that doesnt go through the thalamus
olfactory
what is a taste bud?
supporting cells surrounding taste cells
what is a taste cell
have microvilli or gustatory hair, extending into taste pores
what kind of neurons are olfactory neurons?
bipolar
Three Tunics
fibrous: sclera and cornea
vascular: choroid, ciliary body, iris
nervous: retina
How odorants work?
first messenger: ligand, G protein is activated and binds to adenylate cyclase
second messenger: adenylate cyclase causes buildup of cAMP from ATP
Ion channels open up, depolarizing neuron
Sphincter pupillae
parasympathetic
Dilator pupillae
sympathetic
ciliary body
produces aqueous humor
refraction
bending of light
convergence
light striking a convex surface
focal point
point where light rays converge and cross
focusing
causing light to converge
emmetropia
normal resting condition of the lens, lens is flat
far point of vision
point at which lens does not have to thicken to focus, 20 ft or more from eye
sensory retina
three layers of neurons: photoreceptor, bipolar, and ganglionic
pigmented retina
single layer of cells filled with melanin, enhanses visual acuity by isolating individual photoreceptors, reducing light scattering
rhodopsin
changes shape when struck by light, and separates into opsin and retinal
myopia
nearsightedness
hyperopia
farsightedness
presbyopia
degeneration of accommodation
What are the only neurons that can be replaced?
olfactory neurons
