Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MD4001 Physiology > Opthamology 1 - Eye and Vision (special senses) > Flashcards

Opthamology 1 - Eye and Vision (special senses) Flashcards

1
Q

What are the connections of the eyeball to the brain?

A
  • Optic nerve
  • Chiasm
  • Optic tract
  • LGN (lateral geniculate nucleus)
  • Radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is presbyopia?

A

When lens inside eye looses ability to see things close by

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most common from of refractive error?

A

Presbyopia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does the lens focus on near objects?

A

Thickens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is myopia commonly known as?

A

Short sightedness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is hypermetropia commonly known as?

A

Long sightedness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are normal sized eyes called with normal refraction?

A

Emmetropic - emmo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Are myopic eyes usually smaller or larger than emmotropic/normal eyes?

A

Larger (nearsightedness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What lenses prescribed to help myopia/nearsightedness?

A

Concave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Are hyperopic eyes usually smaller or larger than emmotropic/normal eyes?

A

Smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of lenses are prescribed to help hyperopic eyes/farsighted?

A

Convex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the cells which respond to light on the retina?

A

Photoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the optic nerve made up of?

A

Axons of the ganglion cells of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the central part of the retina called?

A

The macula - very centre is called the fovea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are more rods found?

A

Peripherally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where are cones found generally?

A

Centrally - concentrated in macula highest density in fovea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How many rods are found in the retina?

A

120 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How many cones are found in the retina?

A

6 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do rods and cones compare when converging to ganglion cells?

A

Rods
- High convergence to ganglion cells
Cones
- Low convergence to ganglion cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many types of rods are there?

A

1 type (vision in greyscale)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the different types of cones?

A

3 types

  • Red
  • Blue
  • Green
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How much more sensitve are rods compared with cones?

A

30x more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Do rods and cones have broad spectral sensitivity?

A
  • Rods have broad spectral sensitivity

- Cones have narrow spectral sensitivity

24
Q

What is the blind dpot of the eye due to?

A

Optic disk (aka optic nerve head)

25
Q

What cells are more sensitive rods or cones?

A

Rod cells

26
Q

What do the axons of the ganglions in the retina run along?

A

Superficial surface of the retina and exit at the optic nerve

27
Q

What is the neuroretinal rim?

A
  • Tissue between the border of the cup and the disk
  • Pink/orange
  • Made up of axons of the ganglion cells
28
Q

What is the cup?

A

Space within the centre of the optic nerve can see sclera through it
- Blood vessels enter and exit through here

29
Q

What is the sclera?

A

Tough collaginus coating of the eyeball

30
Q

What does it mean if the margin of the optic nerve is not distinct and clear?

A
  • Swollen optic nerve

- Disease such as raised intracranial pressure

31
Q

WHat hapens if the cup is bigger?

A
  • Neuroretinal rim gets thinner
  • Losing axons from ganglion cells
  • May represent glaucoma
32
Q

What is the main cause of irresversible sight loss in the world?

A

Glaucoma

33
Q

Where do both optic nerves join?

A

Optic chiasm

34
Q

What do optic nerve fibres join after optic chiasm?

A

Optic tracts

35
Q

What axons cross over to the other side of the brain at the optic chiasm?

A

Axons from the medial side of the retina

36
Q

Information from the left visual field is processed where?

A

The right side of the brain

37
Q

What is bitemporal hemianopia?

A

Vision is missing in the outer half of both the right and left visual field
- Chaism damage

38
Q

If you have damage to the right optic nerve where will vision be lost?

A

The right eye

39
Q

If you damage right occipital lobe where will vision be lost?

A

Left visual field (left hemianopia)

40
Q

If you daamage the left optic tract where will vision be lost?

A

Right visual field (right hemianopia)

41
Q

What is a quadrantanopia?

A

Loss of vision in one quarter of the visual field

  • Due to lesion in temporal, parietal or occipital lobe
  • Due to fibres in the optic tract seperating as it travels to the primary visual cortex
42
Q

Information in the upper part of the visual world project where?

A

Lower part of the retina and therefore lower part of the occipita lobe via temporal lobe

43
Q

Information from the lower part of the visual world projects where?

A

Upper part of the retina and therefore lower part of the occipital lobe via parietal lobe

44
Q

What area is often damaged in premature neonates?

A

Optic tract through the pariatal lobe causing an inferior quadrantanopia

45
Q

What are the 2 seperate functional streams of vision?

A
  • Where? stream (dorsal stream) via parietal lobes

- What? stream (ventral stream) via temporal lobes

46
Q

What lobe creates a functional plan based on visual information?

A

Frontal

47
Q

What lobe of the brain stores visual memory?

A

Temporal lobe

48
Q

Dorsal stream dysfunction is usually a result of damage to what part of the brain?

A

Posterior parietal lobe damage

49
Q

What is the Ebbinghaus Illusion?

A

Optical illusion of relative size perception

50
Q

What lobe of the brain hosts the primary vision cortex?

A

Occipital lobe

51
Q

At what age does a babies vision become adult-like?

A

18 months - will continue to mature and develop and leave ‘plastic’ period after 8 years

52
Q

What is periventricular leukomalacia?

A

Damage and holes in white matter of the brain around ventricles due to ischaemic damage

53
Q

What are the features of dorsal stream dysfunction?

A
  • Difficulty in seeing and understanding complex visual images
54
Q

What is simultanagnosia?

A
  • Inability to perceive more than a single object at a time

- Result of parietal lobe damage

55
Q

What is achromatopsia?

A
  • Inability to see colour

Bilateral anterior occipital brain damage

56
Q

What lobe of the brain serves the function of attention?

A

Parietal

MD4001 Physiology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions