B10 The Human Nervous System (unfinished)

Question 1

What is the function of the Cornea?

Answer 1

Transparent layer at the front of the eye which bends light into the eye

Question 2

What is the function of the Ciliary Muscles?

Answer 2

Changes the shape of the lens by relaxing or contracting

Question 3

What is the function of the Retina?

Answer 3

Contains receptor cells which are sensitive to light intensity and colour

Question 4

What is the function of Rods and Cones?

Answer 4

Rods- sensitive to light intensity
Cones- sensitive to colour

Question 5

What is the function of the Suspensory Ligaments?

Answer 5

Connect the lens to the ciliary muscles

Question 6

What is the function of the Optic Nerve?

Answer 6

Carries impulses from receptor cells on the retina to the bran

Question 7

What is the function of the Pupil?

Answer 7

Hole in the middle of the iris which light enters the eye through

Question 8

What is the function of the Iris?

Answer 8

Coloured part of the eye, contains muscles that control the diameter of the pupil, therefore how much light enters the eye

Question 9

What is the function of the Sclera?

Answer 9

Tough supporting wall of the eye (white area)

Question 10

What is the function of the Lens?

Answer 10

Can change shape to focus light onto the retina

Question 11

How does the pupil change shape in Dim light?

Answer 11

• receptors in the eye detect change in the environment
• Radial muscles contract
• Circular muscles relax
• Pupil dilates
• More light enters the eye

Question 12

How does the pupil change shape in bright light?

Answer 12

• Receptors in the eye detect change in the environment
• Radial muscles relax
• Circular muscles contract
• Pupil constricts
• Less light enters the eye

Question 13

How does the lens change through accommodation to view a nearby object?

Answer 13

• Ciliary muscles contract
• Suspensory ligaments slacken
• Lens becomes short and fat
• Light is refracted more by the lens to focus more on nearby object

Question 14

How does the shape of the lens change by accommodation the view a distant object?

Answer 14

• Ciliary muscles relax
• Suspensory ligaments tighten
• Lens becomes long and thin
• light is refracted less, allowing eye to focus on the distant object

Question 15

What is the function of the Pituitary gland?

Answer 15

‘Master Gland’
Responsible for regulating many body functions, controlling activity of other glands

Question 16

What is the function of the Cerebral Cortex?

Answer 16

Outer layer of neural tissue, responsible for consciousness, memory, intelligence and language

Question 17

What is the function of the Medulla?

Answer 17

Controls unconscious activities like breathing and heart rate

Question 18

What is the function of the Cerebellum?

Answer 18

Responsible for muscle coordination and movement

Question 19

What is the function of the Spinal Cord?

Answer 19

Part of the CNS

Question 20

What is the CNS?

Answer 20

Central Nervous System
Brain + Spinal Cord

Question 21

Describe a reflex arc?

Answer 21

• Stimuli sensed by receptors
• Electrical impulse passed along from receptor to sensory neurone to CNS
• Impulse diffused as chemical across synapse between sensory neurone and relay neurone in CNS
• Impulse then passed as chemical across synapse between relay neurone and motor neurone
• Impulse passes from motor to effector organ (muscle or gland)
• Stimulates response (muscle contraction or gland secretes chemical substance)