Chapter 6 - Detecting & Regulating Change Flashcards
What is homeostasis?
Homeostasis is the process of keeping the body’s internal environment fairly constant, within limits.
What is a reflex?
- a rapid, automatic response to a change in the internal or external environment.
What are the characteristics of a reflex?
- 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
What is a reflex arc?
The pathway an impulse follows in travelling from a receptor to an effector
What is the first stage of a reflex arc?
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.
What is the second stage of a reflex arc?
A sensory neuron carries the nerve impulse from the receptor to the CNS.
What is the third stage of a reflex arc?
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.
What is the fourth stage of a reflex arc?
A moron neuron carries the nerve impulse from the CNS to the effector.
What is the fifth stage of a reflex arc?
An effector receives the nerve impulse and carries out the appropriate response. Effectors are muscle cells or secretory cells.