Special Senses Part 2 - The eye Flashcards

1
Q

What are the 4 walls of the bony orbit?

A

Superior
Inferior
Lateral
Medial

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

Label the parts of the bony orbit?

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

What are the accessory structures of the eye?

A

Eyebrows
Eyelashes
Eyelids
Extrinsic muscles that move the eyeballs
Lacrimal apparatus

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

Label the basic eye features?

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

What is the process of the ‘tear system’ (lacrimal apparatus)?

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

Identify the extraocular muscles?

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

Identify the layers of the eyeball?

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

What is the fibrous layer (fibrous tunic) of the eye & what does it contain?

A

–> Is the outer coat of the eyeball.
–> Contains anterior cornea & the posterior sclera.

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

What is the function of the cornea and the sclera?

A

Cornea:
Transmits and refracts incoming light.

Sclera:
Supports eye shape and protects it.

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

What is ‘conjunctiva’ and what surface does it cover?

A

It is an epithelial layer which covers the sclera.

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

What is the vascular tunic?

A

–> The middle layer of the eyeball.
–> Composed of the choroid, ciliary body, and iris.

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

What is the choroid?

A

A thin membrane that lines most of the internal surface of the sclera.

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

What is the function of the choroid?

A

Supplies nourishment to the retina.

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

What does the ciliary body consist of?

A

–> Consists of the ciliary processes (folds on the inner surface of the body whose capillaries secrete a aqueous humor fluid).
–> Consists the ciliary muscle (a smooth muscle that alters the shape of the lens for viewing objects close up or at a distance).

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

What are the 2 functions of the lens?

A
  1. A transparent structure that focuses light rays onto the retina.
  2. Contains zonular fibers or suspensory ligaments which attach the lens to the ciliary muscle and hold the lens in position.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the iris?

A

The coloured part of the eyeball.

17
Q

What does the iris contain?

A

It includes both sphincter circular smooth muscle fibers and dilator pupillae radial smooth muscle fibers.

18
Q

What is the function of the sphincter and dilator pupillae muscles?

A

They regulate the amount of light entering the pupil by decreasing or increasing the size of the pupil.

  1. The sphincter pupillae reduces the pupil size.
  2. The dilator pupillae increases the pupil size
19
Q

What happens to the pupil when there is bright versus low light?

A

Bright light -> pupillary constriction
Sphincter pupillae contracts (parasympathetic innervation).

Low light -> pupillary dilation
Dilator pupillae contracts (sympathetic innervation).

20
Q

What is the retina and its 2 layers?

A

–> Is the third and inner coat of the eyeball.
–> The neural layer and pigmented layer.

21
Q

What is the function of the retina?

A

Converts light that enters into your eye into electrical signals your optic nerve sends to your brain which creates the images you see.

22
Q

What is the function of the pigmented layer of the retina?

A

–> Absorbs extraneous light.
–> Provides vitamin A for photoreceptor cells.

23
Q

What is the function of the neural layer of the retina?

A

Detects incoming light rays, where the light rays are converted to nerve impulses and transmitted to the brain.

24
Q

Where are the fovea centralis of the retina located?

A

A small depression in the centre of the macula lutea (or yellow spot) in the exact centre of the retina.

25
Q

What is special about the fovea centralis of the retina?

A

It is the area of highest visual acuity or resolution (sharpness of vision) because of its high concentration of cones.

26
Q

How does information move from photoreceptors?

A

From photoreceptors, information flows to bipolar cells and then from bipolar cells to the ganglion cells.

27
Q

Why is the optic disc known as the blind spot of the eye?

A

Because the optic disc contains no rods or cones, we cannot see an image that strikes the blind spot.

28
Q

What does Ophthalmoscopy involve?

A

It visualises the posterior part or the fundus of the eye, which includes the retina, optic disc, choroid and blood vessels.

29
Q

What are the 2 segments of the eye?

A

The lens divides the interior of the eyeball into two cavities or segments:
1. Anterior segment (located anterior to the lens).
2. Posterior segment (located posterior to the lens).

30
Q

What is the fluid found in the anterior segment of the eye and what is its function?

A

Aqueous humor:
Helps maintain the shape of the eye and nourishes the lens and cornea, neither of which has blood vessels.

31
Q

What is the fluid/body found in the posterior segment of the eye and what is its function?

A

Vitreous body:
Helps prevent the eyeball from collapsing and holds the retina flush against the choroid.

32
Q

What is intraocular pressure and what is it produced by?

A

–> The pressure in the eye.
–> Produced mainly by the production and drainage of the aqueous humor.

33
Q

What is the function of intraocular pressure?

A

Maintains the shape of the eyeball and keeps the retina smoothly pressed against the choroid.

34
Q

Identify the order of the visual pathway?

A

Retina –> Optic nerve –> Optic chiasm –> Optic tract –> Thalamus –> Midbrain –> Projection fibres (optic radiation) –> Primary visual cortex of the occipital lobe.

35
Q

Label the structure of the eyeball?

A
36
Q

Label the structure of the eyeball?

A