B10 Brain, Eye & Eye Problems

B10.4, 10.5 & 10.6 (not all off B10!)

The Brain

Label the parts of the brain, 4 labels

dont look at definitions

What do the parts do?

2 methods of studying the brain and how they work

1. Magnetic resonance imaging - mri scans use strong magnetic fields and radio waves to produce detailed images of the inside of the body

2. Electrically stimulating parts of the brain and seeing what it makes move

The eye

Label this eye

Functions of the parts

Adaption to light intensity / Iris reflex

In DIM light, the pupil is _____

In BRIGHT light, the pupil is ____

In DIM light, the pupil is dilated

In BRIGHT light, the pupil is contracted

pupil is…

dilated = big/small

contracted = big/small

dilated = big

contracted = small

To dilate, the ___ muscles contract

and the ___ muscles relax

To dilate the RADIAL muscles contract

and the CIRCULAR muscles relax

To contract the pupil, the ___ muscles contract

and the ___ muscles relax

To contract the CIRCULAR muscles contract

and the RADIAL muscles relax

not a question stupid

Accommodation

To focus on a NEAR object:

• the ciliary muscles ___

• the suspensory ligaments ___

• the lens becomes ___

so it refracts light rays more ___

• the ciliary muscles contract

• the suspensory ligaments loosen

• the lens becomes thicker

so it refracts light rays more strongly

To focus on a DISTANT object:

• the ciliary muscles ___

• the suspensory ligaments ___

• the lens becomes ___

so it ___ refracts light rays

• the ciliary muscles relax

• the suspensory ligaments tighten

• the lens becomes thin

so it only slightly refracts light rays

light rays meet on the ___ at a point called the ___

light rays meet on the retina at a point called the fovea

Common problems of the eye

Short sightedness is called ___

Long sightedness is called ___

Short sightedness is called myopia

Long sightedness is called hyperopia

In myopia the eye can’t focus on ___ objects

In hyperopia the eye can’t focus on ___ objects

myopia = distant

hyperopia = nearby

In myopia the uncorrected image forms ___ the retina

in front of the retina

in hyperopia the uncorrected image forms ___ the retina

behind the retina

Why does myopia occur?

• lens too strong

• eyeball too long

Why does hyperopia occur?

• Lens too weak

• eyeball too short

What kind of lens is needed to correct myopia?

i.e. type of glasses or contact lenses

Concave

What kind of lens is needed to correct hyperopia?

Convex

Give 2 new technological treatments for hyper/myopia

• Hard and soft contact lenses

• Laser surgery to change shape of the cornea

• Replacement lens in the eye (surgery)