Vision Flashcards Preview

MCAT Pysch/Soc > Vision > Flashcards

Flashcards in Vision Deck (39)
1

Sclera

The thick structural layer that covers the exposed portion of the eye (the white of the eye)

Doesn't cover the cornea

2

Choroidal vessels and retinal vessels

Blood vessels that supply the eye with nutrients

3

Retina

The innermost layer of the eye - in the back of the eye

Converts incoming photons of light to electrical signals

Part of the CNS & develops as the outgrowth of brain tissue

Detects images

4

Cornea

Where the light passes FIRST through

Gathers and focuses the incoming light

5

(2) chambers th the front eye is divided into:

Anterior chamber
Posterior chamber

6

Anterior chamber

Lies in front of the iris

7

Posterior chamber

Between the iris and the lens

8

Iris

Controls the size of the pupil

Colored part of the eye

9

The iris has 2 muscles. What are they?

Dilator pupillae
Constrictor pupillae

10

What is the function of the dilator pupillae (muscle in the Iris)?

Opens the pupil under sympathetic stimulation

OPENS PUPIL

11

What is the function of the constrictor pupillae (muscle in the Iris)?

Constricts the pupil under parasympathetic stimulation

CLOSES PUPIL

12

Aqueous humor

Produced by the ciliary body

Bathes the front part of the eye before draining into the canal of Schelemm

13

Lens

Helps control the refraction of the incoming light

Located right behind the iris

Held in place by suspensory ligaments connected to the ciliary muscle

14

As the muscle contracts, it pulls on the ..

Suspensory ligaments and changes the shape of the lens
Known as ACCOMODATION

15

Vitreous

Transparent gel that supports the retina

Located behind the lens

16

Retina contains:

Rods and cones

17

Rods

Detect light and dark

Function best in reduced light

Can permit night vision

18

Cones

Detects colors in 3 forms (short [blue],medium [green], and long [red] wavelengths)

19

Duplicity theory of vision

States that the retina contains 2 kinds of photoreceptors: those specialized for light & dark detection and those specialized for color detection

20

Macula

Has high concentration of cones

Central section of the retina

Center most point: fovea

21

Fovea

Center most point of the macula

Contains only cones

22

As you move away from the fovea...

Concentration of cones decease and concentration of rods increase

23

Blind spot

Located where the optic nerve leaves the eye

There are no photoreceptors here

24

How do rods and cones connect?

Through bipolar cells

25

Bipolar cells synapse with...

Ganglion cells which group together to form the optic nerve

26

As the number of receptors that converge through the bipolar neurons onto one ganglion cell increases ...

The resolution decreases

27

Amacrine and horizontal cells

Receives input from multiple retina cells in the same area before the information is passed on to ganglion cells

Important for edge detection as they increase our perception of contrast

28

What is the visual pathway ? (starting from the eye)

Optic nerve ➡️ optic chiasm ➡️ optic tracts ➡️ lateral geniculate (LGN) of the thalamus ➡️ visual radiations ➡️ visual cortex

29

Optic chiasm

Contains fibers crossing from the nasal side of the retina (temporal visual fields) of both sides

30

Visual radiations run through ...

Temporal and parietal lobe

31

Visual cortex is in which lobe

Occipital

32

Parallel processing

The ability to simultaneously analyze and combine information regarding color, shape and motion

This can be compared to our memories to determine what is being viewed

Example : recognizing a moving car very easily from a distance because they are familiar with the usual motions and shapes of cars

33

Parvocellular cells

Detect shapes

With high spatial recognition and low temporal resolution

34

Magnocellular cells

Detects motion

With low spatial recognition and high temporal resolution

35

Spatial resolution

Permit us to see very fine details when thoroughly examine an object

36

Pupil

Allows passage of light from anterior to posterior chamber

37

Ciliary body

produces aqueous humor, accommodation of lens

38

Canal of Schlemm

Drains the aqueous humor

39

The eye is used to detect:

Light in the form of photons