Chapter 6 - Detecting & Regulating Change Flashcards Preview

Human Biology - Unit 3 > Chapter 6 - Detecting & Regulating Change > Flashcards

Flashcards in Chapter 6 - Detecting & Regulating Change Deck (9)
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1
Q

What is homeostasis?

A

Homeostasis is the process of keeping the body’s internal environment fairly constant, within limits.

2
Q

What is a reflex?

A
  • a rapid, automatic response to a change in the internal or external environment.
3
Q

What are the characteristics of a reflex?

A
  • a stimulus is required to trigger a reflex - a reflex is not spontaneous
  • a reflex is involuntary - it occurs without any conscious thought
  • a reflex response is rapid - only a small number of neurons are involves
  • a reflex response is stereotyped - it occurs the same way each time
3
Q

What is a reflex arc?

A

The pathway an impulse follows in travelling from a receptor to an effector

4
Q

What is the first stage of a reflex arc?

A

The receptor is either the ending of a sensory neuron or a specialised cell associated with the end of a sensory neuron. The receptor reacts to a change in the internal or external environment by initiating a nerve impulse in the sensory neuron.

5
Q

What is the second stage of a reflex arc?

A

A sensory neuron carries the nerve impulse from the receptor to the CNS.

6
Q

What is the third stage of a reflex arc?

A

There is at least on synapse. The nerve impulse may be passed directly to a motor neuron or there may be one or more interneurons, which direct the impulse to the correct motor neuron.

7
Q

What is the fourth stage of a reflex arc?

A

A moron neuron carries the nerve impulse from the CNS to the effector.

8
Q

What is the fifth stage of a reflex arc?

A

An effector receives the nerve impulse and carries out the appropriate response. Effectors are muscle cells or secretory cells.