Nervous Tissue- Neuron & Synapses & Classification

Nervous Tissue

cells are densely packed & intertwined

What are two main type of Cell in Nervous Tissue?

Neurons & Support Cells

Neurons

transmit electrical signals

Support Cells (Neuroglial cells in CNS) 

Non-excitable; surronds & wrap neurons 

Neuron - Dendrites 

branches from cell body. Site for receiving signals from other cells & transmitting them to the cell body 

Neuron - Axon

only 1; the impulse generator sending excitatory signal away from cell body

Neuron - Terminal Bouton

Neurotransmitters released from vesicles onto target

Presynaptic neuron 

conducts signal toward a synapse 

Postsynaptic Neuron

transmits electrical activity away from a synapse

Synaptic Vesicles 

membrane-bound sacs containing neurotransmitter 

Where are Synaptic vesicles located?

Presynaptic Side 

Synaptic cleft

space that separates the plasma membrane of the two neurons

Multipolar

Most abundant in body. 

Where are Multipolar found? 

Major neuron type in the CNS 

Bipolar

Rare

Where are Bipolar Neurons found?

Some special sensory organs (Olfactory mucosa, eye, & ear)

Unipolar (Pseudounipolar) 

common only in dorsal root ganglia of the spinal cord & sensory ganglia of the cranial nerves

Where are Unipolar (Pseudounipolar) found?

mainly in the PNS