B10

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  • Created by: JeremyLin
  • Created on: 05-06-20 11:46
What is homeostasis?
Regulation of internal conditions for optimal functionality within an organism made in response to external changes in the environment
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Why is homeostasis important?
It is important as it helps maintain the conditions within an organism to a suitable level, allowing cell functions and enzymes to work normally
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What are receptors, coordination centres and effectors?
Receptors - cell that detect changes in the internal or external environmentCoordination centres - receive and process info from receptors, send out signals and coordinate response Effectors - muscles or glands that carry out the changes
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Name 3 examples of internal body conditions needed to be maintained
Body temperature - Water content of body - Glucose concentration in blood
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How does the nervous system work?
Sensory receptors pass on electrical signals through neurones until it reaches the central nervous system. The motor neurones carry on the impulse from the CNS to the effectors. Muscles respond by contracting. Glands respond by secreting chemicals.
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What are reflexes for?
Reflexes are to avoid danger or harm. They also take care of basic body functions.
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Name 2 examples of basic body functions carried out using reflexes
Breathing and moving food through the digestion system
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What 3 neurones are involved in reflexes?
Sensory, relay and motor
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What is the reflex pathway in order?
Stimulus - Receptor - Sensory Neurone - Relay Neurone - Motor Neurone - Effector - Response
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What are the 3 different regions of the brain and their functions?
Cerebral cortex - Consciousness, intelligence, memory and language Cerebellum - coordinating muscular activity and balance Medulla - unconscious activity such as controlling heartbeat and activity
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What is the main function of the sclera?
It offers protection and has a transparent area at the front of the eyeball to let light go through. The cornea also lets light rays come in at different angles and directions, ensuring it's focused on the retina.
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What does the iris do?
The iris controls the size of the pupil and the amount of light that is entering the eye.
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What do the ciliary muscles and suspensory ligaments do?
They change the shape of the lens so it can fine focus light on the retina.
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What does the optic nerve do?
It carries impulses from the retina to the brain
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What does accommodation involve?
Changing the shape of the lens of the eye so it can focus better on nearby or distant objects.
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How do the ciliary muscles, lens and suspensory ligaments help focus on close objects?
The ciliary muscle contracts, the suspensory ligaments loosen and the lens become thicker so it can refract light rays strongly
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How do the ciliary muscles, lens and suspensory ligaments help focus on further objects?
The ciliary muscle relax, the suspensory ligaments tighten and the lens are pulled thin so light rays are only refracted slightly
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How can defects in the eye be treated?
Through spectate lenses (refract light rays so they can focus on the retina) hard and soft contact lenses, laser surgery and replacement lenses in the eye.
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Card 2

Front

Why is homeostasis important?

Back

It is important as it helps maintain the conditions within an organism to a suitable level, allowing cell functions and enzymes to work normally

Card 3

Front

What are receptors, coordination centres and effectors?

Back

Preview of the front of card 3

Card 4

Front

Name 3 examples of internal body conditions needed to be maintained

Back

Preview of the front of card 4

Card 5

Front

How does the nervous system work?

Back

Preview of the front of card 5
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