Neurons Flashcards
what are neurons
Neurons are nerve cells. They are highly specialised cells of the nerve cells. Neurons generate electrochemical nerve impulses and carry information from one part of the body to another.
what is glial tissue
Glial cells support, protect and provide neurons with nutrition, and insulate them from each other.
what is an example of glial tissue
schwann tissue
how can neurons be classified
- structure
- function
what are the three functional types of neurons
- Afferent
- Efferent
- Interneurons
how do afferent neurons function
- take nerve impulses from receptors o the central nervous system
- are sensory receptors
how do efferent neurons function
- take nerve impulses from the central nervous system to effectors
- are motor/effector
how do interneurons function
These neurons located in the central nervous are the link between the sensory and motor neurons
what other names is interneurons function
- association neurons
- connector
- relay
what are four structural types of neurons
- Unipolar
- Bipolar
- Multipolar
- pseudounipolar
describe unipolar neurons
Has only one extension called an axon from the cell body. It is not found in humans, they are found in insects.
describe bipolar neurons
Have one axon and one dendritic extending from the cell body. Both axon and dendrite may have many branches at their ends.
where are three places bipolar neurons be found
- ear
- eye
- nose
describe multipolar neurons
Have one axon and several dendrites extending from the cell body. All somatic motor neurons and most interneurons.
describe what pseudounipolar neurons are
Has properties of both unipolar and bipolar neurons. There is a single axon from the cell body which branches off into dendrites and axon terminals. They are usually sensory axons.
what is the cell body also known as
- cyton
- soma
what is the cell body
The cell body is part of the neuron that contains the nucleus and is responsible for controlling the functioning of the cell. Consists of granular cytoplasm due to a cluster of ribosomes. There are abundant organelles.
what are dendrites
- Short and high-branched.
- Synapse with other neurons or receptors.
- Transmit electrochemical impulses towards the cell body.
what are axons
- Is a single, long nerve fibre.
- Carries nerve impulses away from the cell body.
- Terminate at the synaptic end bulbs.
- Connect with muscles, glands and neurons.
what is it called when axons connect to muscles
neuromuscular junction
what is it called when axons connect to glands
neuroglandular junction
what is the myelin sheath
The myelin sheath is a white, fatty sheath surrounding the axon of most neurons.
what produces the myelin sheath of the peripheral nervous system
Schwann cells
what are the three functions of the myelin sheath
- speeds up nerve transmission
- acts as an insulator
- protects nerve fibres
what are the gaps between the myelin sheath on an axon called?
nodes of Ranvier
what is the outermost structure of a Schwann cell
neurilemma
what is a synapse
Is a space or junction between two adjacent neurons
what is a neurotransmitter
A molecule that carries a nerve impulse across a synapse
