2 - Nervous Communication Flashcards
What is a receptor?
A cell, or protein on a cell surface membrane, that detects a stimulus. They are only specific to one type of stimulus
What is a coordinator?
Part of the nervous system which formulates an appropriate response to a stimulus before sending impulses to an effector
What is an effector?
A cell that brings about a response to a stimulus, to produce an effect
What are the three main neurone?
- Sensory Neurone
- Motor Neurone
- Relay Neurone
What is the function of the sensory neurone?
Transmits electrical impulses from receptors to the CNS - The brain and spinal chord
What is the function of the motor neurone?
Transmits electrical impulses from the CNS to effectors
What is the function of the relay neurone?
Transmit electrical impulses between sensory neurones and motor neurones
What is a neurotransmitter?
A chemical that transmits a nerve impulse across a synapse
What is a synapse?
A junction between a neurone and another neurone or between a neurone and an effector cell
What is a reflex?
A rapid involuntary response to a reflex
Describe a reflex arc
Stimulus Receptors Sensory neurone CNS Motor neurone Effectors Response
Why Is a nerve impulse specific to a target cell only?
Because it released a chemical messenger directly onto it, producing a response that is usually rapid, short lived and localised
What are the two major divisions of the nervous system?
1- The CNS (central nervous system) - which is made up of the brain and spinal chord
2- The PNS (Peripheral nervous system) - Which is made up of pairs of nerves that originate from either the brain or the spinal chord
Why are reflex arcs important?
- They protect the body from harm
- Effective from birth, and do not have to be learnt
- They are fast because the neurone pathway is short
- The action is rapid as there is no decision making process
- They are involuntary and do not require decision making powers from the brain so it is free to carry out more complex responses
