Homeostasis

Created by: LaurenWoolley11
Created on: 09-07-17 11:17

What is an effector?

A cell, tissue or organ that brings about a response- either a muscle or a gland

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Define homeostasis.

The maintenance of a relatively stable internal environment (within narrow) limits even when the external environment may be changing

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How do organsims achieve homeostasis?

Through negative feedback mechanisms

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What happens in a positive feedback mechanism?

A deviation from the normal range is amplified resulting in further deviation

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Give an example of a biological positive feedback mechanism.

In childbirth- release of hormone oxytocin stimulates uterine contractions/the baby pushes on the cervix/more oxytocin released/more contractions

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Give an example of a thermostable environment.

Deep/open ocean

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Name the two receptors involved in thermoregulation and what they detect the temperature of.

1)Peripheral thermoreceptors dectect temperature of the skin 2)thermoreceptors in the hypothalamus which detect the temperature of blood flowing past the brain

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What is an ectotherm?

An organism which exerts minimal physiological control over its internal body temperature

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Give two examples of ectotherms.

Reptiles and amphibians

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Give two examples of endotherms.

Mammals and birds

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When we are too hot- why do the sweat glands release sweat?

They recieve an action potential from the brain. The sewat evaporating from the skin cools it as it takes heat energy with it.

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Which effectors act when we are too cold? What do they do?

Erector pilli muscles contract-trap air/arterioles constrict-less blood flows close to surface/muscles contract in spasms-releases heat energy from respiration.

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Other cards in this set

Card 2

Front

Define homeostasis.

Back

The maintenance of a relatively stable internal environment (within narrow) limits even when the external environment may be changing

Card 3

Front

How do organsims achieve homeostasis?

Back

Card 4

Front

What happens in a positive feedback mechanism?

Back

Card 5

Front

Give an example of a biological positive feedback mechanism.

Back

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Homeostasis