Unit 2 chapter 5 Flashcards
Three stages to a nervous response:-
- Stimuli- a change in the environment
- receptors-groups of cells that detect stimuli
- effectors-cause a response (muscles,glands)
Stimulus
A change in the environment
Receptors
Groups of cells that detect stimuli
Effectors
Cause a response (muscles,glands)
Receptor cells
Change stimuli into electrical impulses
Travel along nerves to the CNS (central nervous system) made up of brain and spinal cord
Where are receptor cells found?
In sense organs
Nerves
Carry electrical impulses around your body so it can react to changes in the environment
Sensory neurones
Carry electrical impulses from CNS to effectors
0.7 of a second
Relay neurons
Found in CNS,carry electrical impulses from sensory neuron to motor neuron
Motor neurons
Carry electrical impulses from CNS to effectors
Reflex
Automatic reactions that occur without thinking about them
What waves does sound travel as?
Longitudinal waves
What sounds can humans hear? (Hertz)
Between 20 hertz-20,000
With longitudinal waves,do particals vibrate parallel to the way energy travels?
Yes
Why can’t sound travel through space?
Sound waves cannot travel in a vacuum
What are hormones?
Chemical messengers that travel around your body in the blood secreted by glands.
What do hormones control?
Body processes that need constant adjustment to maintain a constant internal environment
What is homeostasis?
The maintenance of a constant internal environment
How does your body control its internal environment?
Using negative feedback
Where are hormones produced?
In glands.
What is controlled by homeostasis?
Body temperature,body water
How is type 1 diabetes controlled?
By objecting insulin,maintaining a healthy diet and ensuring regular physical activity
How is type 2 diabetes controlled?
Diet and exercise,avoiding eating league quantities of carbohydrate-rich foods,exercise after eating
Insulin also injected when this is not enough
What part of your brain monitors body temperature?
The thermoregular centre
What happens if your body temperature is too low or high?
It causes changes in skin returning body temperatures to normal
How does sweat cool down your body?
Water in sweat evaporates
What is dilation?
Widening of blood vessels
What is constriction?
Narrowing of blood vessels
What do chemical reactions control?
Everything that happens in your body
What do acids and bases cause damage to?
Skin,teeth,internal organs
What are the chemical reactions that body cells carry out controlled by?
Enzymes
