Homeostasis Flashcards
What must the body keep control of ??
Water levels
Blood glucose concentration
Body temperature
What do all control systems contain???
- receptors
- co ordination centre
- effectors
What does the receptor do, and how an example.
Detect stimuli (changes in environment) -skin
What does the co ordination centre do, and give an example.
The brain or the spinal cord or pancreas
-receive and process information from the receptors
What does the effectors do, and give an example.
Muscle or gland
- bring about a response and restore optimum levels
What is the order of the nervous systems response?
Stimuli-receptor-CNS-effector-response
Why is homeostasis important ?
Enzymes need the right conditions to function properly
What is a sensory neurone?
The neurones that carry information as electrical impulses from the receptors to the CNS
What is a motor neurone?
The neurones thus carry electrical impulses from the CNS to effectors
What are effectors?
All your muscles and glands, which respond to nervous impulses
What do receptors do??
Detect stimuli
What do effectors do?
Bing about change
What is the connection between two neurones called ? And how does it work?
When the electoral impulses reach the end of a neurone it stimulates the release of a chemical. chemicals diffuse across the synapse to activate the chemical in the next neurone
What is homeostasis?
The maintenance of a stable environment in response to changes both internal and external conditions
What neurones are in a reflex arc?
- sensory neurone
- relay neurone
- motor neurone
What is a reflex arc ?
The passage of information in a reflex from receptor to effector
What are the differences between the nervous system and reflexes ?
- reflexes bypass the conscious part of the brain
- responses use either the brain or spinal cord
- reflexes are fast and prevent injury
Why are reflexes quicker ?
You don’t have to think about the response
What is the name given to the connection between two neurones
Synapse
What factors effect human reaction time ?
- drugs
- caffeine
- age
- gender
What is reaction time?
The time it takes to respond to a stimulus
Give the control variables when investigatin reaction time
- same person
- same hand
- same height
Why is using a computer rather than a ruler more precise?
Removes human error
Why is using a computer rather than a ruler more accurate?
- It records it in milliseconds
* removes possibility that the person can detect when the ruler is dropped
What does he nervous system allow humans to do?
React to their surroundings and co ordinate their behaviour
How is information passed around the body?
As electrical impulses
What is a stimulus ?
A change in the environment
