Neurons and Synaptic Transmission Flashcards
What is a motor neuron?
neurons that form synapses with muscles and control their contractions
What is a neurotransmitter?
chemical substances that play an important part in the workings of the nervous system by transmitting nerve impulses across a synapse
What is a relay neuron?
neurons that allow sensory and motor neurons to communicate with each other
What is the most common type of neuron in the CNS?
relay neurons
What is a sensory neuron?
neurons that carry nerve impulses from sensory receptors to the spinal cord and the brain
What is a synapse?
the conjunction of the end of the axon of a neuron and the dendrite/cell body of another
What is synaptic transmission?
refers to the process by which a nerve impulse passes across the synaptic cleft from one neuron (the presynaptic neuron) to another (the postsynaptic neuron)
What cells are the brain made up of?
glial cells and astrocytes
What are amongst the cells in the brain?
neurons
How many neurons does the average human brain have? (+ how many are connected to these)
100 billion neurons and each neuron is connected to 1,000 other neurons
Where do the dendrites of neurons receive information from?
sensory receptors or other neurons
What happens to the information after the dendrites of neurons receive it?
the information is then passed down to the cell body and on to the axon
What happens when the information has reached the axon?
it travels down the axon in the form of an electrical signal known as an action potential
What are neurons?
cells that are specialised to carry neural information throughout the body
What are the 3 types of neurons?
- sensory neurons
- moor neurons
- relay neurons
What are the 3 key features of a neuron?
- cell body
- dendrites
- axon
What is the job of dendrites?
to receive signals from other neurons or from snesory receptors
What are dendrites connected to?
the cell body
What is the cell body?
the control centre of the neuron
From the cell body, where is the impulse carried?
along the axon, where it terminates at the axon terminal
What is the myelin sheath?
an insulating layer that forms around the axon
How long is a neuron?
can vary from a few millimetres up to one metre
Give 3 examples of sensory receptors?
receptors for vision, taste and touch