The Neuron Flashcards
What are specialized cells that make up the nervous system?
Neurons
Neurons receive, process, and transmit information between each other.
What structure of a neuron receives information from other neurons?
Dendrites
Dendrites carry information from the synapses to the cell body.
What part of the neuron controls metabolism and maintenance?
Cell body (soma)
The cell body receives messages from other neurons and contains the nucleus.
What is the function of the axon in a neuron?
Carries the nerve impulse away from the soma towards the axon terminal
The axon communicates with other nerves or cells.
What is the myelin sheath?
A white, fatty substance that covers the axon
It insulates the axon, preventing electrical interference and increasing the efficiency of nerve impulses.
Fill in the blank: Myelin can increase the speed of nerve impulses, allowing them to travel up to _______.
400km per hour
What are small gaps in the myelin sheath called?
Nodes of Ranvier
These gaps allow the electrical impulse to ‘jump’ from one node to another, increasing speed.
What do axon terminals do?
Transmit messages to the next neuron
Axon terminals have ‘terminal buttons’ that secrete neurotransmitter chemicals.
What is the junction between two nerve cells called?
Synapse
Neurons do not touch; there is a tiny space between them.
How do neurons communicate?
Chemically via neurotransmitters
The presynaptic neuron spills neurotransmitters into the synapse for the postsynaptic neuron to take up.
What are glial cells?
Cells that provide support to neurons in four ways:
* Holding neurons in place
* Supplying nourishment and oxygen
* Removing dead neurons
* Producing myelin
What are the three main types of neurons?
Motor neurons, sensory neurons, interneurons
What do motor neurons do?
Communicate messages from the CNS to muscles
Motor neurons are also called efferent neurons and are mostly multipolar.
What is the role of sensory neurons?
Carry sensory information from the body to the CNS
Sensory neurons are also called afferent neurons and are mostly pseudounipolar.
What is the function of interneurons?
Carry information between motor and sensory neurons in the CNS
They transmit impulses between other neurons as part of a reflex arc and are mostly not myelinated.
