The structure & Function of sensory, relay & motor neurons Flashcards
Define Neurons
Neurons are nerve cells within the nervous system that process & transmit messages through electrical & chemical signals, they provide nervous system with its primary means of communication
3 Types of neurons:
* Motor neurons
* sensory neurons
* Relay neurons
All 3 types of neurons have dendrites,cell bodies & axon
Outline sensory neurons
These are cells that send info to brain regarding senses, they carry messages from the peripheral nervous system, PNS towards the Central nervous system (CNS)
They have long dendrites & short axon
they are affarent neurons as carry info from PNS towards CNS
They keep brain informed about external & internal enviroment via processing info from eyes,ears,nose,skin
Outline motor neurons
Found in central nervous system (CNS)
They connect the CNS to effectors such as muscles & glands in order to control muscle movements
They are efferent neurons as they carry info away from CNS towardsPNS
They have short dendrites & long axons
When a motor neuron is stimulated they release neurotransmitters that bind to receptors on muscles to trigger a response, which leads to movement
Outline relay neurons
Also known as interneurons as they can take on role of sensory & motor neurons in nervous system
They connect the sensory neurons to the motor neurons
They are based in the CNS & carry signals across this part of the nervous system
They have a short axon and short dendrites
Outline structure of neurons-use book
Outline electric transmission , the firing of neuron
When a neuron is in its resting state the inside of the cell is negatively charged compared to the outside. When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for split second causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of the neuron
