Important Notes Flashcards by Jen Becker

What fluid fills the bony labyrinth

perilymph (ECF, CSF)

How well did you know this?

Not at all

Perfectly

What fluid fills the membranous labyrinth

endolymph (ICF)

How well did you know this?

Not at all

Perfectly

Saccule and Utricle sense linear movement because they contain

hair cells embedded in an otolithic membrane that also has calcium carbonate crystals embedded on the surface.
1. Head movement 2. Rocks shift 3. Otolithic membrane shifts 4. Hair cells deflection 5. Nerve fires

How well did you know this?

Not at all

Perfectly

Semicircular ducts detect angular movement because they contain

endolymph that moves opposite to the head, which causes the stereocilia to move toward the kinocilia and kinocilia to move toward the midline –> increased AP firing rate

How well did you know this?

Not at all

Perfectly

What is the discharge rate of neurons in the semicircular ducts at rest?

90 spikes/sec

How well did you know this?

Not at all

Perfectly

PPRF is the center for

HORIZONTAL gaze

How well did you know this?

Not at all

Perfectly

MLF is the center for

VERITCAL gaze

How well did you know this?

Not at all

Perfectly

What level is the PPRF and the vestibule nuclei?

caudal pons

How well did you know this?

Not at all

Perfectly

Optokinetic Nystagmus

named for the direction of the saccade, fixate on a moving object until eyes reach periphery of orbit then snap back to center of vision

How well did you know this?

Not at all

Perfectly

OEF

smooth pursuit of object moving from R–>L; L OEF- L pontine nucleus - R flocculus - R vestibular nucleus - L PPRF

How well did you know this?

Not at all

Perfectly

Cold Caloric Test

Endolymph conduction current away, hyperpolarizing ear, eyes deviate slowly toward irrigated ear, then snap back to opposite ear

How well did you know this?

Not at all

Perfectly

Inability to to adduct one eye, other eye is fine

Ipsilateral lesion of ascending MLF or CN3 nuclei

How well did you know this?

Not at all

Perfectly

Ventral portion of otic vesicle gives rise to

saccule and cochlear duct

How well did you know this?

Not at all

Perfectly

Dorsal portion of the otic vesicle gives rise to

utricle, semicircular ducts, and endolympahtic duct

How well did you know this?

Not at all

Perfectly

Tympanic Membrane is formed from

ectoderm of meatal plug, endoderm of tubotympanic recess, and mesoderm between

How well did you know this?

Not at all

Perfectly

Superior Olivary Complex

1st point of integration from both sides, sensitive to the differences in time of arrival and intensity from both ears to localize sound

How well did you know this?

Not at all

Perfectly

Aminoglycosides

cause sensorineural hearing loss (Treatment for Meniere’s Disease)

How well did you know this?

Not at all

Perfectly

Lens is formed by

the surface ectoderm

How well did you know this?

Not at all

Perfectly

Derivatives of the optic cup

Retina, ciliary body, and iris

How well did you know this?

Not at all

Perfectly

Sclera is continuous with

dura mater

How well did you know this?

Not at all

Perfectly

Retinal Pigment Epithelium (RPE) function

absorption of excess light (melanin), store Vitamin A, and meet nutrition needs of photoreceptors

How well did you know this?

Not at all

Perfectly

Ration of rods:cones

20:1

How well did you know this?

Not at all

Perfectly

Viagra inhibits

phosphodiesterase enzyme activity causing visual disturbances

Dark Current

depolarized to -40mV in dark

Vertical Flow of information

photreceptor->bipolar->ganglion

Horizontal Flow of information

horizontal and amacrine cells modulating activity of bipolar cells

Lateral Geniculate Nucleus Layers 1-6

Layers 2, 3, 5 = uncrossed ipsilateral fibers | Layers 1, 4, 6 = decussated contralateral fibers

Magnocellular Division

Layers 1 and 2 (rods) detect light and motion

Parvocellular Division

Layers 3 and 6 (cones) color and spatial discrimination

Geniculocalcarine Tract - Temporal

Upper visual field info, to temporal lobe and to VENTRAL portion of radiations

Geniculocalcarine Tract - Parietal

Lower visual field info, to parietal lobe and to DORSAL portion of radiations

Geniculocalcarine Tract - Intermediate

Macula info

Magnocellular fibers synapse on Layer 4 then

travel to layer 2-3 = DORSAL PATHWAY

Parvocellular fibers synapse of Layer 4 or blobs then

travel to Layer 2-3 = VENTRAL PATHWAY

Fibers cross for visual integration between sides via

splenium of corpus callosum

Afferent limb of PLR lesion

no response with either eye to light shown in one eye, light shown in other eye produced response in both

Efferent limb of PLR lesion

affected eye no direct of consensual response

Argyll-Robertson

ARP and PRA (lesion in pretectum)

Optic Chiasm lesion caused by

pituitary tumor

Lateral Optic chiasm lesion

Aneurysm of internal carotid artery

Optic Tract lesion

may be with/without PLR

Temporal Loop Lesion

Superior quadrant vision loss

Parietal Loop Lesion

Inferior quadrant vision loss

Unilateral lesion to primary visual cortex

Occlusion of POSTERIOR CEREBRAL ARTERY or CALCARINE BRANCH, macula apring ue to collateral branches from MIDDLE CEREBRAL ARTERY

Lesion of Posterior Hypothalamus result in

HYPOthermia

Lesion of the Anterior Hypothalamus result in

HYPERthermia

IL-1 enters the brain and

stimulates neurons in pyrogenic zone, produces cytokines and prostaglandins

PGE-2 increases the set-temp of body by

activating the cold-sensitive neurons and inhibiting the warm-sensitive neurons

Anterior Hypothalamus/Preoptic area

Sleep center; lesion = wakefulness

Posterior Hypothalamus

Awake center; lesion = hypersomnolence

PGD2

promotes sleep

PGE2

promotes wakefulnes

Decussation of the olfactor fibers is via

Anterior commissure

Entorhinal COrtex

Olfactory Association Center

NTS contains

secondary neurons for ascending taste pathway to VPM of thalamus

Septal area of limbic system function

Pleasure Center; lesion = loss of libido