Maciej Nervous system Maciej Flashcards
(10 cards)
Define Homeostasis
The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
What three conditions does the body need to maintain at a constant level ?
Water levels, blood-glucose concentration, temperature
In the bodies response system, what are the receptors ?
Receptors are parts of the body that detect changes in the environment (a stimulus)
In the bodies response system what are the co-ordination centres ?
Parts of the body which process the information from the receptors e.g. (brain, spinal cord, pancreas)
In the bodies response system, what is the effector ?
The part of the body that initiates a response based on the change
Describe the pathway of a nervous system response
- A stimulus is detected by a receptor
- An electrical impulse is sent via the sensory neurone to the central nervous system (brain or spinal cord)
- The central nervous system sends an electrical impulse via the motor neurone to the effector
- The effector issues a response
Why is there a gap between neurones and what is it called ?
- The tiny gap is called a synapse
- The synapse makes sure that the electrical impulse travels in only one direction
What are reflex actions ?
Reflex actions are fast automatic responses, they do not initially involve the brain but rather the spinal cord
What is the pathway of an electrical impulse during a reflex action called ?
Reflex arc
Describe the pathway if a reflex arc
- Stimulus is detected by receptor and sends an impulse
- The impulse travels via the sensory neurone to the central nervous system (Spinal Cord)
- Electrical impulse sent over Relay neurone then to the motor neurone which travels to the effector which issues a response