Senses Flashcards
1
Q
what is the name of the three layers of the eye?
A
- Cornea/ sclera= outer layer
- Uveal tract= middle
- Retina= inner
2
Q
What are the main funtions of the eye?
A
- conversion of light to a nerve impulse
- transmission of light to the nerves at the back of the eye
- direction and focus of gaze
- protects delocate strucutres
3
Q
What 6 compoenents does vision require?
A
- healthy visual pathway
- transparency
- refractive power
- direction of gaze
- metabolic funtion
- brain capable of perciving image
4
Q
What are the chararistics of the cornea?
A
- covers the anterior one fifth of the eyeball
- dome shaped oval with 5 layers which are transparent
- the main funtion is protection and refraction of light
5
Q
What are the main funtions of the Pupil?
A
- regualte the amount of light entering the posterior segement of the eye to avoid bleaching retinal pigments
6
Q
Which 2 nerves are invloved within pupillary responce?
A
- the optic( cranial nerve II) and occulomotor(cranial nerve III) and they both react in unison
7
Q
What is the Lens and what is its funtion?
A
- the lens is a clear, curved disc that sits behind the iris and infront of the vitreous.
- it is the part of the eye which focuses light and colour to create a sharp image
- a cataract= cloudy area of the lens
8
Q
What is the diffrence between cranial nerves II and III?
A
- Cranial nerve II(optic) helps with your ability to see wheras III (oculomotor)helps with the ability to move and blink your eyes.
9
Q
What are some other cranial nerves and thier roles in vision?
A
- IX( trochlear)- ability to move your eyes up and down or back and forth
- X(trigeminial)- sensations in your face and cheecks, taste and jaw movments
- XI(Abducens)- ability to be able to move your eyes
- XII( facial)- facial expressions
10
Q
What is the two main purposes of the ear?
A
- enhanses the conduction of sound through transduction= hearing
- maintains a sense of body propioception= balance
11
Q
where are the Ossicles found?
A
- they cross the middle ear cavity
12
Q
What is the main funtion of the inner ear?
A
- the coclea is the inner ear and it contains a fluid called perilymph.
- ossicles tranmit sound waves from the eardrum
13
Q
What are some of the issues that can occur with hearing?
A
- less homeostatic efficiency leads to conduction deafness = presbycussis
- tinnitus is due to brain activity, not due to overstimualtion of hearing apparatus