Homeostasis,nervous system,synapses and reflexes Flashcards
What is Homeostasis?
Regulation of conditions inside your body to maintain a stable internal enviromnment in response to internal and external changes of conditions.
What are the three main control system?
- Body Temperature
- Blood glucose content
- Water content of body
What is a stimuli?
A change in environment that you might need to respond to.
What restores the optimum level?
The negative feedback mechanism
What is involved in the negative feedback loop?
- level changes from optimum
- receptors detect this change
- coordination centre receives and organises response
- effectors respond
What are the three types of neurones?
- Sensory
- Relay
- Motor
What does the sensory neurone do?
It carries information as electical impulses from receptors to CNS
What does the relay neurone do?
- Carries electrical impulses from sensory to motor neurones
- found in CNS
What does the motor neurone do?
-carries electical impulses from CNS to effectors
What are effectors?
Effectors are muscles or glands which respond to a stimulus.
What is a synapse?
A gap/junction between 2 neurones
What happens whe an electrical impulse reaches a synapse?
- A chemical neurotansmitter is released( in presynaptic neurone)
- this diffuses across the gap (and binds to receptors in the postsynaptic neurone)
- this stimulates a new electrical signal in the next neurone
What is the role of a synapse?
-Ensures that the electrical impulses only travel in ONE
DIRECTION
-They are the basis of MEMORY
-They enable the nervous system to CONTROL
IMPULSES
-The place where DRUGS CAN INTERACT with the
nervous system
Why do synapses slow down transmission of a nervous impulse?
Because the diffusion of chemicals across the gap takes time
What are reflexes?
- -fast automatic responses to stimuli
- bypass conscious brain
