B10 Flashcards
What is homeostasis ?
Regulation of internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
Why homeostasis is important?
Need the right conditions for enzymes actions. Enzymes have an optimum temperature
What is an automatic control system?
Regulates internal environment , nervous system and hormonal system are examples
What do automatic control systems regulate?
- blood glucose concentration
- body temperature
- water levels
What is the response to na automatic control system?
Nervous responses or chemical responses
What do receptors do?
Detect stimuli (changes in environment)
What are coordination centres?
Recieve and process information from recoetors . These include the brain, spinal cord and pancreas
What is the effector?
Muscles or glands which bring about responses which restore optimum levels
What does the nervous system enable us to do?
React to surroundings and coordinate behaviour.
Steps in the central nervous system ?
Stimulus Receptor Sensory neurone CNS Motor neurone Effector Response
What is the central nervous system?
In vertebrates (animals with backbones) this consists of the brain , spinal cord only. Connected to the body by the sensory and motor neurones. It receives information from receptors and gives a response
What is the sensory neurone?
Carry information as electrical impulses from the receptors to the cns?
What carried electrical impulses?
Neurones
What is the motor neurone.
Carries electrical impulse from the receptors to the cns
Types of receptors?
- taste receptors in the tounge
- sound receptors in the ears.
What are synapses?
Gaps between neurones
What happens when an electrical impulse wnats to pass a synapse?
Transfere across by chemicals which diffuse across the gap . The chemicals then set of to the next electrical signal in the next neurone.
What are reflex actions?
Automatic and rapid , they do not involve the conscious part of the brain. They can reduce the chance of being injured.
Examples of a reflex action?
If someoje shines a bright light in your eye , your pupils get smaller to stop them from getting damaged. Or if you shock your body it releases adrenaline automatically
What is the passage of information called in a reflex action?
Reflex arc
How is a reflex arc different than a normal reaction?
Goes through the spine al cord or an unconscious part of the brain to make the reaction quicker.
What are the chemicals called that diffuse across the synapse?
Neurotransmitter chemicals
