smc-3659-60-Nervous System

BIOLOGY, M8 2014 HSC 31a

The biological structure shown is part of one of the systems in the body.

Name the biological structure. (1 mark)

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Outline the steps involved in this system's response to a stimulus. (3 marks)

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i. Nerve cell/neuron

ii. Steps involved in system’s response to a stimulus

A stimulus is detected by a receptor nerve cell which convert the stimulus to an electrochemical impulse, which is then carried by sensory cells to the brain.
The signal reaches a certain segment on the brain depending on what signal was received, where an action is determined to be carried out.
Motor neurons carry the signal to an effector, which carries out the response

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i. Nerve cell/neuron

ii. Steps involved in system’s response to a stimulus

A stimulus is detected by a receptor nerve cell which convert the stimulus to an electrochemical impulse, which is then carried by sensory cells to the brain.
The signal reaches a certain segment on the brain depending on what signal was received, where an action is determined to be carried out.
Motor neurons carry the signal to an effector, which carries out the response.

♦ Mean mark (ii) 48%.

Identify TWO responses of a named endotherm to a decrease in body temperature. (2 marks)

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Outline the role of the nervous system of an endotherm in maintaining homeostasis when its body temperature changes. (2 marks)

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a. Vasoconstriction and shivering.

b. Body temperature maintenance in endotherms:

This is achieved via negative feedback loops.
Temperature receptors in the brain and skin detect changes in body temperature.
The central nervous system receives a signal via the receptors.
Muscles or glands (effectors) then receive nerve signals sent from the central nervous system.

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a. Vasoconstriction and shivering.

b. Body temperature maintenance in endotherms:

This is achieved via negative feedback loops.
Temperature receptors in the brain and skin detect changes in body temperature.
The central nervous system receives a signal via the receptors.
Muscles or glands (effectors) then receive nerve signals sent from the central nervous system.

Which of the following body systems is involved in detecting and responding to environmental changes?

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`D`

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The nervous system detects and responds to environmental change using sensory nerves.

`=>D`