Nervous tissue Flashcards
What are neurons?
Special cells that form a continuous network, extending all over the body.
Neurons make up the nervous system
Why do neurons need a continuous supply of oxygen and glucose?
Neurons have a very high metabolic rate and will not survive without oxygen.
What are glial cells?
Supporting cells
What is the function of glial cells?
Make myelin and support and protect neurons
What is the structure of a neuron?
Have a cell body and neuron fibres
What is the function of Neuron fibres?
Allow for nerve impulses to be carried long distances.
What does the fibres in the neurons consist of?
Dendrites and neurons
What are Dendrites?
Short, tapering processes that branch out to provide a large surface area to receive signals from other neurons
What is the function of Dendrites?
Conduct impulses TOWARDS the cell body.
What is an axon?
Branch off at its end to form terminal branches
What is the function of an axon?
Conducts impulses AWAY FROM the cell body.
What are the different type of Neurons?
Sensory/unipolar Neurons,
Connector Neurons,
Motor/multipolar neurons
What are sensory/unipolar neurons?
One fibre is attached to cell body
Why are sensory neurons referred as afferent neurons?
Carry impulses from receptors TOWARDS the CNS where sensation interpreted.
What are connector neurons?
They are multipolar neurons found in CNS, make up 99% of neurons
What are multipolar neurons?
Many fibres are attached to cell body
What is the function of the connector neurons?
Receive impulses from sensory neurons and pass them on to other neurons?
What a some of the other names given to Connector neurons?
Relay neurons,
Association neurons,
Interneurons
Why are Motor Neurons are referred as efferent neurons?
Carry impulses AWAY FROM the CNS to effectors, for appropriate response can be brought.
What does Nervous Tissue consist of?
Neurons and neuroglia
What is the structure of a of a motor neuron?
Dendrites Cell body: Nissel Body, cell membrane, nucleus, cytoplasm, neuroplasm Node of ranvier Schwann Axon Myelin Sheath Terminal branches Synaptic knob
What is the function of a cell body?
Controls the metabolism of the cell
What is the function of node of Ranvier?
Allows rapid conduction of impulses by allowing them to jump from one node to the next
What is the function of Schwaan cells
Secretes the myelin sheath when wrapped around axon
What is the function of the myelin sheath
Forms an electrical insulation to prevent impulses from being disrupted from activity
What is the function of terminal branches?
Carry impulses to synaptic knob
What is the function of a synaptic knob?
Forms a synapse with another neuron , a muscle or a gland cell
