Nervous Communication Flashcards
What do receptors do?
Detect stimuli - they can be cells or proteins on cell surface membranes.
They communicate with the effectors via the nervous system or the hormonal system, or sometimes using both.
What are effectors?
Cells that bring about a response to a stimulus, to produce an effect.
Include muscle cells and cells found in glands, e.g. the pancreas.
What do sensory neurones do?
Transmit electrical impulases from receptors to the CNS.
What do motor neurones do?
Transmit electrical impulses from the CNS to the effectors.
What do relay neurones do?
Transmit electrical impulses between sensory and motor neurones.
How is the peripheral nervous system (PNS) split up?
Into the somatic and autonomic nervous systems. The autonomic nervous system is also split into the sympathetic and parasympathetic nervous system.
What is the function of the somatic nervous system?
To control conscious activities. E.g. running and playing video games.
What is the function of the autonomic nervous system?
To control unconscious activities. E.g. digestion.
What is the function of the sympathetic nervous system?
Gets the body ready for action: ‘fight or flight’.
What is the function of the parasympathetic nervous system?
Calms the body down: ‘rest and digest’.
Reflex arc.
Receptors in the skin detect a 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 (e.g. a muscle).
Your muscle contracts to move away from the stimulus (e.g. heat which will cause damage to skin).
Properties of nervous system communication.
Localised - when an electrical impulse reaches the end of a neurone, neurotransmitters are secreted directly onto target cells.
Short-lived - neurotransmitters are quickly removed once they’ve done their job.
Rapid - electrical impulses are really fast to allow animals to react quickly to stimuli.
