Question

9). A patient complains to you about their blurred vision. Describe three (3) possible causes for this blurred vision with your patient.

10). Sequence the events that occur in the ear during hearing by describing the structures that sound waves will contact on their way into the body & name the lobe of the brain that eventually receives the message.

11). Name & describe the structure & function of the three (3) layers of the eye from outermost to innermost.

12). Define excitability, contractility, extensibility & elasticity. State why each of these properties is necessary for normal muscle function.

Answer 1

9) Blurred vision causes -

- Refractory error - myopia or hypermetropia may cause blurred vision.

- presbyopia

- Corneal Edema

- catract

10) Process of hearing -

Sound waves --> Extert Ear --> Tympanic membrane --> enters middle ear -->Malleus --> Incus -- Stapes --> foot plate of stapes --> oval window --> inner ear --> then in chochlea travels in Scala vestibuli --> Scala tympani --> Organ of corti --> 8th nerve --> Cochlear nucleus --> superior olivary nucleus --> Inferior colleiculus --> medial Geniculate body --> primary audiotory cortex

3) 3 layers of eye --

Outermost -

Sclera and cornea - Makes external covering of eye, 2/3 rd post - sclera white opaque, ant 1/3 rd - cornea transparent - for transmission of light inside eye

Middle - uvea - provide nutrition and support

Inner - Retina - It is neural layer having- photoreceptor like rods and cone. Ang generate light impulse.

12) excitibility - It is ability of muscle to get stimulated by impulse. Important for voluntary and reflex action

Contractility - ability of muscle to shorten. It is required to do work.

Extensibility - is the maximum length the muscle can be stretched.

Elasticity - tendency of muscle to regain its normal size and shape.