Lab Quiz 3

Question 1

Cornea

Answer 1

Transmits and refracts light, is curved, air-cornea interface

Question 2

Iris

Answer 2

Controls amount of light entering eye

Question 3

Circular muscles

Answer 3

Constrict pupil controlled by parasympathetic nervous system

Question 4

Radial muscles

Answer 4

Dilate the pupil controlled by sympathetic

Question 5

Lens

Answer 5

Focuses light on retina, involved in accommodation

Question 6

Accommodation

Answer 6

Ability of the lens to keep an object focused on the retina as distance to the object varies

Question 7

Distant vision

Answer 7

Over 20 ft away, ciliary relaxed suspensory taut/stretched lens thin/flat

Question 8

Close vision

Answer 8

Ciliary contracted, suspensory relaxed, lens round/thick

Question 9

Near point of vision

Answer 9

Minimum distance from the eyes an object can be brought into focus

Question 10

Presbyopia

Answer 10

Loss of accommodating ability with age, less flexibility of lens zonular attachment moves forward, lens can’t thicken for close vision

Question 11

Retina

Answer 11

Layer of neural tissue with photoreceptors

Question 12

Rods

Answer 12

Extremely light sensitive, black/white vision, low resolution

Question 13

Cones

Answer 13

Require more light, color, high resolution

Question 14

Cone types

Answer 14

S cones: short wavelengths, blue
M cones: medium wavelengths, green
L cones: long wavelengths, red

Question 15

Cone defects

Answer 15

Leads to color blindness, inherited or from damage to the neural pathway, Red green is most common

Question 16

Optic nerve

Answer 16

Collection of axons from the retinal ganglion cells that exits eye
No rods or cones → blind spot

Question 17

Fovea centralis

Answer 17

In the macula lutea best visual acuity, only cones no other layers so light falls directly on cones

Question 18

Saccadic movements

Answer 18

Shifts parts of visual field onto fovea

Question 19

Convergence

Answer 19

Rods snaps w/ one bipolar, many bipolar w/ one ganglion
Increases dim light sensitivity but low acuity

Question 20

Nystagmus

Answer 20

Tone of one of six muscles that keeps eyes in midline position is weak causing eyes to drift slowly in one direction followed by a rapid movement back to correct position

Question 21

Rhodopsin

Answer 21

Photo sensitive chemical in rods
11 cis to all trans in light
Has to rebuild before receptor can be stimulated again

Question 22

Positive afterimage

Answer 22

Eye adapted to bright light, bright image still seen from continued firing of photoreceptors

Question 23

Negative afterimage

Answer 23

Dark image of lightbulb seen on light background from breaching of rhodopsin

Question 24

Afterimage colors

Answer 24

R →g
B →o
Y→p

Question 25

Sound waves

Answer 25

Alternating zones of high and low pressure traveling through a medium

Question 26

Frequency

Answer 26

Cycles per second in hertz, pitch 20-20, 000 for humans

Question 27

Loudness

Answer 27

Intensity in decibels, loudness Amplitude of wave humans 0 - 80 dB

Question 28

Outer ear

Answer 28

Pinna (auricle) and external auditory meatus, auricle funnels in sound waves into eam which channels them to tympanic membrane

Question 29

Malleus and stapes

Answer 29

Malleus attached tympanic, stapes to oval window

Question 30

Ossicles

Answer 30

Transmit vibration from middle to inner ear

Question 31

Inner ear

Answer 31

Cochlea and vestibular apparatus

Question 32

Conduction deaf

Answer 32

Sound waves to oval window impaired many causes

Question 33

Sensorineural deaf

Answer 33

Impulses from cochlea not conducted to auditory cortex, certain frequencies

Question 34

Rinne’s

Answer 34

Tuning fork on mastoid move to outside ear Hear sound outside ear → normal, air greater than bone No sound → either type of deafness bone conduction greater

Question 35

Weber's

Answer 35

Tuning fork on midsagittal of skull Normal → equal sound both sides Middle ear prob → affected ear sounds louder due to conduction deafness Inner ear → sound in affected ear softer from sensorineural dearness

Question 36

Vestibular nystagmus

Answer 36

Involuntary eye movements from vestibular inputs

Question 37

Muscle function

Answer 37

Convert chemical energy to mechanical work

Question 38

Fiber to neuron

Answer 38

Motor neurons innervate many fibers, each fiber innervated by only one motor neuron

Question 39

Motor unit

Answer 39

Single motor neuron and all fibers that it innervates

Question 40

Finer muscle control

Answer 40

Smaller motor units

Question 41

Strong contraction

Answer 41

Larger motor units

Question 42

Contractions of high strength

Answer 42

Recruitment of larger and larger motor units

Question 43

Smooth controlled movements

Answer 43

Graded contractions according to load placed on muscle

Question 44

Tonus

Answer 44

Constant slight tension to keep muscle ready

Question 45

Degree of muscle contraction

Answer 45

# of motor units activated, frequency of stimulation

Question 46

Twitch

Answer 46

Single shock, quickly contracts then relaxes

Question 47

Latent period

Answer 47

Time between stimulus and start of contraction

Question 48

Contraction phase

Answer 48

End latent to muscle tension peak

Question 49

Relaxation

Answer 49

Peak tension to end contraction

Question 50

Summation

Answer 50

Second twitch will partially add on top of first with second shock

Question 51

Incomplete tetanus

Answer 51

Relaxation time decreasing with more frequent shocks

Question 52

Complete tetanus

Answer 52

Frequency where there is no relaxation

Question 53

Treppe

Answer 53

Staircase effect

Question 54

Electromyography

Answer 54

Uses surface electrodes to detect, amplify, and record changes in skin voltage produced by underlying muscle contraction Recording → EMG

Question 55

Muscle fatigue

Answer 55

Reversible exercise -induced reduction in muscle's ability to generate force

Question 56

Dynamometer

Answer 56

Measures muscle force

Question 57

% Increase in clench

Answer 57

(Strongest - weakest)/weakest x 100