Biology 1b (See continued version)

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1. What does the nervous system allow you to do?
To react to your surroundings and coordinate your behaviour.
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2. What is your nervous system made up of? (two things)
The central nervous system and the perpheral nervous system (receptors and neurones)
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3. What are receptors?
Specialised nerve endings that generate nerve impulses.
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4. What receptors do animals have?
Light receptors in your eye, sound receptors and balance receptors in your ear. Taste receptors on tongue. Smell receptors in nose. Touch, pressure, and pain receptors and temperature receptors in your skin.
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5. What are neurones?
Specially adapted cells that carry a nerve impulse.
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6. What are nerve impulses?
Electrical messages/signals and are carried along the axon (long thin part of the cell).
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7. What are sensory neurones?
carry nerve impulses from the receptors from the brain.
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8. What do relay neurones do?
They make connections between neurones inside the brain to your spinal chord.
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9. What do motor neurones do?
Carry nerve impulses from your brain to your muscles and glands.
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10. How have neurones adapted to their job?
They have an elongated shape to make connections from one part of the body to another. They have an insulating sheath to speed up nerve impulses. They have dendrites (branched endings) to allow a single neurone to act on many muscle fibres.
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11. How does a electrical impulse cross a synapse?
An electrical impulse travels down a neurone until it reaches a synapse (small gap between neurones). A transmitter substance diffuses across the synapse. The transmitter binds with receptor molecules on the next neurone.
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12. What are voluntary actions? Give an example.
Actions under the conscious control of your brain, you decide to react. Eg. Tasting something bitter and spitting it out.
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13. What are reflex actions? Give an example.
(Also known as involuntary actions) Bypass your brain to give a fast automatic responce to the stimulus to protect body from harm. Eg. Pupil reflex automatically controls entry of light. Knee jerk reaction. Withdrawing your hand from a hot plate.
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14. What is the pathway of a voluntary action?
Stimulus - Receptor - Sensory Neurone - Brain - Motor Neurone - Effector - Responce.
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15. What is the pathway of a reflex action?
Stimulus - Receptor - Sensory Neurone - Relay Neurone (spinal chord) - Motor Neurone - Effector - Responce.
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nervous system, drugs, and homeostatis
The iris is the coloured part of the eye, controls light entering. Light refracted by cornea, lens focuses onto retina so the rays coverge together. Light sensitive receptor cells than cause nerve impulses along sensory neurones to optic nerve+ brain
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17. What is the lens? Explain what is around the lens as well.
A clear flexible bag of fluid surrounded by circular muscles that change the shape of the lens. Suspensory ligaments attach lens to the ciliary muscles.
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18. What happens to the eye when receiving light from a near object?
The ciliary muscles contract, suspensory muscles relax and the lens is short and fat to refract the light alot.
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19. What happens to the eye when receiving light from a distant object?
Ciliary muscles relax. Suspensory muscles contract. The lens is long and thin because light only needs to be refracted a little.
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20. Name some common eye defects.
Long sight, short sight, red-green colour blindness.
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21. Why do some people have red-green colour blindness?
Some of the specialised cells in the retina that detect red and green light are missing.
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22. What are long and short sight caused by?
The eyeball or the lens being the wrong shape, so the light rays can't be accurately focused on the retina.
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23. How can long and short sight be corrected?
Contact lenses, glasses or laser eye surgery. Convex lens = long sight Concave = Short sight
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Other cards in this set

Card 2

Front

2. What is your nervous system made up of? (two things)

Back

The central nervous system and the perpheral nervous system (receptors and neurones)

Card 3

Front

3. What are receptors?

Back

Preview of the front of card 3

Card 4

Front

4. What receptors do animals have?

Back

Preview of the front of card 4

Card 5

Front

5. What are neurones?

Back

Preview of the front of card 5
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