6A: Nervous communication Flashcards
What do receptors detect?
They detect stimuli - they can be cells or proteins on the cell surface membranes. There are specific receptors for specific stimuli
What do effectors do?
They produce a response to a stimulus to produce an effect.
How do receptors communicate with effectors?
Via the nervous system or hormonal system, sometimes using both
How does the nervous system send information?
As electrical impulses called neurones
What do the 3 types of neurone do?
Sensory - sends electrical impulses from receptors to CNS
Motor - sends electrical impulses from CNS to effectors
Relay - transmits electrical impulses between sensory and motor neurones
How does the nervous system work?
A stimulus is detected by receptor cells and an electrical impulse is sent along a sensory neurone.
Neurotransmitters take the information to the next neurone, which then sends an electrical impulse.
The CNS processes the information and sends an electrical impulse along the motor neurone to an effector which produces a response.
What is the CNS made up of?
The brain and spinal cord
What is the peripheral nervous sytem made up of?
Somatic nervous system and Autonomic nervous systems
What is the autonomic nervous system made up of?
Sympathetic and Parasympathetic Nervous system
What is a reflex?
Where the body responds to a stimulus without making a conscious decision to respond
Why are reflexes so rapid?
Because information travels really fast from receptors to effectors
How can a reflex arc be overridden?
If there is a relay neurone involved its possible to override it
Why is nervous system communication localised?
When an electrical impulse reaches the end of a neurone, Neurotransmitters are secreted directly onto target cells so the nervous response is localised.
Why is nervous system communication rapid?
Because they are quickly removed once they’ve done their job.
Why is nervous system communication rapid?
Because the electrical impulses are really fast which allows animals to react quickly to stimuli.
What is the peripheral nervous system made up of?
The neurones that connect the CNS to the rest of the body
What do the somatic and autonomic nervous systems control?
Somatic controls conscious activities, and autonomic controls unconscious activities
What do the sympathetic and parasympathetic nervous systems control?
Parasympathetic nervous system calms the body down, and the sympathetic nervous system gets the body ready for action
What is an example of a reflex arc?
- Thermoreceptors in the skin detect the heat stimulus
- The sensory neurone carries impulses to the relay neurone
- The relay neurone connects to the motor neurone
- The motor neurone sends impulses to the effector
- Your muscle contracts to withdraw your hand to stop it from being damaged
