B5 - Homeostasis And Response Flashcards
What is the definition of the word homeostasis?
Maintaining a constant internal environment
How does the body control internal conditions?
With automatic control systems
What are the three key components of an automatic control system?
Receptors, coordinators, effectors
What is the mechanism that the automatic control systems use to keep conditions normal?
Negative feedback
What two systems does the body have to maintain homeostasis?
The nervous system and the endocrine system
What is the proper term for something that happens outside of the body that the body needs to respond to?
A stimulus
What are receptors?
Cells that detect stimuli
What are effectors?
They are cells that receive nervous impulses and bring about a change
What is the central nervous system (CNS)?
Brain and spinal cord
What does the CNS do?
Coordinates a response based on the information it receives
How are electrical impulses transported from receptors to the CNS?
By the sensory neurones
How are electrical impulses transported from the CNS to the effectors?
By the motor neurones
What are the two main types of effectors?
Muscles and glands
What is a synapse?
A gap between the neurones
How do electrical impulses travel across the synapses?
Chemicals are released and diffuse across the synapse and a new electrical impulse is set off
What are reflexes?
Automatic responses that don’t involve the conscious part of the brain
What is the passage of information in a reflex called?
The reflex arc
Which parts of the CNS do reflex arcs pass through?
Subconscious parts of the brain and the spinal cord
In a reflex arc, what does the information do instead of the CNS making a decision?
Passes through a relay neurone
Are reflexes or usual responses faster?
Reflex
Why are reflexes faster than normal responses?
Because the information doesn’t have to be considered, the brain doesn’t have to decide which signal to send along the motor neurone
What does the cerebral cortex do?
Responsible for consciousness, intelligence, memory and language
What does the medulla do?
Control subconscious activities
What does the cerebellum do?
Responsible for muscle coordination
