B10 The Human Nervous System (unfinished) Flashcards
What is the function of the Cornea?
Transparent layer at the front of the eye which bends light into the eye
What is the function of the Ciliary Muscles?
Changes the shape of the lens by relaxing or contracting
What is the function of the Retina?
Contains receptor cells which are sensitive to light intensity and colour
What is the function of Rods and Cones?
Rods- sensitive to light intensity
Cones- sensitive to colour
What is the function of the Suspensory Ligaments?
Connect the lens to the ciliary muscles
What is the function of the Optic Nerve?
Carries impulses from receptor cells on the retina to the bran
What is the function of the Pupil?
Hole in the middle of the iris which light enters the eye through
What is the function of the Iris?
Coloured part of the eye, contains muscles that control the diameter of the pupil, therefore how much light enters the eye
What is the function of the Sclera?
Tough supporting wall of the eye (white area)
What is the function of the Lens?
Can change shape to focus light onto the retina
How does the pupil change shape in Dim light?
- receptors in the eye detect change in the environment
- Radial muscles contract
- Circular muscles relax
- Pupil dilates
- More light enters the eye
How does the pupil change shape in bright light?
- Receptors in the eye detect change in the environment
- Radial muscles relax
- Circular muscles contract
- Pupil constricts
- Less light enters the eye
How does the lens change through accommodation to view a nearby object?
- Ciliary muscles contract
- Suspensory ligaments slacken
- Lens becomes short and fat
- Light is refracted more by the lens to focus more on nearby object
How does the shape of the lens change by accommodation the view a distant object?
- Ciliary muscles relax
- Suspensory ligaments tighten
- Lens becomes long and thin
- light is refracted less, allowing eye to focus on the distant object
What is the function of the Pituitary gland?
‘Master Gland’
Responsible for regulating many body functions, controlling activity of other glands