Lab Quiz 3

What is the main difference between rods and cones?

Rods detect light intensity, cones detect color

Which condition results when the focal point falls behind the retina?

Hyperopia (farsightedness)

At the optic chiasma, what happens to visual nerve fibers?

Fibers from the nasal field cross; temporal stay

What is the purpose of the Amsler grid test?

To detect retinal or optic nerve changes

Which process allows the eye to focus on near objects?

Contraction of the cilia muscle thickening the lens

Where are high-frequency sounds detected in the cochlea?

Near the oval window

Which type of hearing loss results from ossicle damage or tympanic

infection?

Conductive

What structure provides information about balance and spatial orientation?

Vestibule apparatus

Which test compares air conduction to bone conduction?

Rinne test

During rotational nystagmus, what do the eyes do while turning right?

Slowly move left, then snap right

What is a motor unit?

motor neuron and the muscle fibers it innervates

Muscles with small motor units (1:10 ratio) are typically responsible for:

Precise fine movements

What does motor unit recruitment achieve?

It increases contraction strength by activating more units

What causes muscle fatigue?

Depletion of ATP and buildup of waste

What does EMG measure?

Skin voltage from electrical muscle activity

What best defines antagonistic muscles?

Muscles that oppose each other’s action

Which muscles flex the elbow?

Biceps brachii and brachialis

What is the agonist during wrist flexion?

Flexor group

Which two muscles are monitored during the arm-wrestling EMG?

Biceps brachii and pronator teres

What does EMG show in antagonistic muscle studies?

Electrical coordination between agonist and antagonist muscles