Homeostasis
This lesson covers:
- What 'homeostasis' is
- The roles of receptors, coordination centres, and effectors
- The differences between the nervous system and the endocrine system
- What we mean by 'negative feedback'
What is homeostasis?
Maintaining a stable internal environment despite changing conditions
Changing an internal environment within the body
Maintaining a constant external environment
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Why does the body need to maintain optimal conditions?
For optimal enzyme action and cell function
To kill pathogens
For slow enzyme action and cell function
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Which of these are considered 'internal conditions'?
(Select all that apply)
Room temperature
Blood glucose concentration
Blood pH
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True or false? Homeostasis ensure internal conditions stay exactly constant, they don't fluctuate at all.
True
False
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Which of these are considered 'external conditions'?
(Select all that apply)
Room temperature
Blood oxygen concentration
The amount of fluids you drink
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effector / receptor
Homeostasis relies on automatic control systems.
In what order are signals passed along the control system?
âž” coordination centre âž”
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What is the role of a receptor?
Carries out the response
Interprets changes and organises a response
Detects changes in the internal or external environment
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What is the role of a coordination centre?
Detects changes in the internal or external environment
Carries out the response
Interprets changes and organises a response
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Where are the coordination centres located in the body?
(Select all that apply)
Muscles
Brain
Skin
Spinal cord
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Name the two types of effectors and state what they do.
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Is the nervous system or the endocrine system faster acting?
Nervous
Endocrine
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Which system acts more generally across the body, the nervous system or the endocrine system?
Endocrine
Nervous
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Homeostasis relies on a system of , meaning whenever the levels of something get too high they're brought back down, and whenever the levels of something get too low, they're brought back up.
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If our body temperature gets too high, negative feedback will cause our temperature to:
Increase further
It won't do anything
Decrease back down
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How does negative feedback work?
Any change in a system causes an action that reverses the change
Any change in a system causes an action that amplifies the change
Stops any changes from taking place
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