2nd semester: VISION

Question 1

Stereopsis is a physiologic mechanism involved in ___________________

Answer 1

depth perception

Question 2

This error of refraction is due to an eyeball that is too long

Answer 2

Myopia

oh MY, that is TOO LONG. chr

Question 3

Cones adapt faster than rods because __________________________.

Answer 3

cones utilize a 2ND pathway for regeneration

Question 4

This process/change is observed when LIGHT strikes the eye from a point source of 6 meters

Answer 4

The lens becomes flat.

Question 5

When entering a movie house while the movie is on-going, which adaptive changes normally takes place?

Answer 5

There is GREATER activation of rods.

Question 6

Mr X claims that he cannot see clearly. Upon consulting a doctor, he was prescribed to wear biCONVEX lenses. Mr. X has _________________

Answer 6

HYPERopia

convex = hyper

Question 7

What is the CORRECT sequence in the photo-transduction of rods and cones in response to LIGHT?

Answer 7

Structural change in rhodopsin –> activation of transducin –> (-) intracellular cGMP –> CLOSURE of Na+ channels –> (-) release of GLUTAMATE
(on the Road, habang nagbabasa ng Trans, GaMit Phone ko, sinara ko bintaNA at nag tusok ng GLUTA (E)

Question 8

A lesion on which part of the visual pathway will result to HETEROnymous hemianopsia?

Answer 8

Optic chiasm

Question 9

Increase in INTRAOCULAR pressure can be due to the following EXCEPT:

Answer 9

Increase in the production of vitreous humor

Question 10

A fly landed on the tip of your nose. What primary extra-ocular muscle did you use to see the fly?

Answer 10

Inferior rectus

Question 11

Which of the following statements is NOT TRUE of phototransduction?

Answer 11

Voltage-gated Na+ channels regulate Na+ conductance in the outer segment.

Question 12

Which of the following is INCORRECTLY paired?

Answer 12

W cells: most abundant

Question 13

Cutting which structure causes blindness in the temporal fields of the left and right eye?

Answer 13

Optic Chiasm
Tandaan!
NASAL part of retina, sees temporal field.
TEMPORAL part of retina, sees nasal field.

Question 14

Pupillary constriction is NOT important in ______________

Answer 14

dark adaptation

Question 15

Which of the color cones absorbs the longest wavelength of light?

Answer 15

red

Question 16

Compression of optic CHIASM by pituitary ADENOMA can lead to ______________________

Answer 16

HETEROnymous hemianopsia

Question 17

Which of the following statements about the lens is INACCURATE

Answer 17

lens has the greatest refractive power

[no, cornea has the greatest RP]

Question 18

Which of these types of ganglion cells transmits signals that detect color, shape and FINE DETAILS of images?

Answer 18

X cells

Question 19

Which of the following is decreased during visual accommodation?

Answer 19

Focal distance

Question 20

Formed by fibers from temporal and nasal hemiretinas of same side

Answer 20

optic nerve

Question 21

Damage to which structure causes blindness in the temporal field of the left eye and nasal field of the right eye?

Answer 21

optic tract

Question 22

Color blindness is more common in males than in females. This is because MOST cases are caused by an abnormal _______________.

Answer 22

recessive gene X chromosome

Question 23

Bleaching of rhodopsin is ____________.

Answer 23

Separation of SCOTOPSIN and ALL-TRANS retinal

Question 24

DOH, as part of its health program, gives Vitamin A to school children to prevent night blindness. This is because Vitamin A is a precursor of

Answer 24

retinAL

Question 25

Refractive power of the lens is LEAST in patients with _________________

Answer 25

HYOpia

Question 26

when focusing on near objects, the following responses takes places EXCEPT

Answer 26

activation of sympathetic nervous system via CN III

Question 27

the layer of retina that is formed by synapses between bipolar and ganglion cells is

Answer 27

inner plexiform layer

Question 28

a lens that refracts light at a focal distance of 20mm has a refractive power of

Answer 28

+50D

Question 29

among the refractive media of the eye, the cornea has the greatest refractive power due to

Answer 29

a higher refractive index

Question 30

Error in refraction that is corrected by using CYLINDRICAL lens

Answer 30

ASTIGmatism

astig si celine

Question 31

the retinal neuron that can generate and send signals to the brain

Answer 31

ganglion cell

Question 32

characteristics that make the central fovea the area of highest visual resolution except

Answer 32

being rod and cone free

Question 33

change that takes place in light adaption

Answer 33

utilization of central retina

Question 34

sequence in the photo-transduction of rods

Answer 34

conversion of 11-cis retinal to all-trans retinal forming metarhodopsinll -> activation of transduction -> hydrolysis of cGMP to GMP by phosphodiesterase -> closure of cGMP-gated Na channels -> Hyperpolarization

Question 35

pupillary contraction is important in

Answer 35

near response

Question 36

optic disk and fovea centralis are alike in that they both are

Answer 36

rod free portion in the retina

Question 37

which of the following physiologic mechanism is observed during visual accommodation

Answer 37

relaxation of lens ligament

Question 38

diopteric medium that can easily change its refractive power

Answer 38

lens

Question 39

refractive power of the lens is greatest in patients with

Answer 39

myopia

Question 40

a lesion in this will lead to loss of vision in the left nasal and left temporal visual fields of an eye

Answer 40

optic nerve

Question 41

which of the following statements regarding rods is correct

Answer 41

lower resolution than the cones

Question 42

individuals with protanmalous and tritanopia are considered

Answer 42

dichromats

Question 43

physiologic response when light reaches the retina

Answer 43

closure of sodium channels