NS Histology Flashcards
What are characteristics of a multipolar neuron?
Two or more dendrites
One axon
Mostly motor neurons and interneurons
What are characteristics of bipolar neurons?
One dendrite
One axon
Associated with special senses in eye and ear
What are characteristics of pseudounipolar neurons?
One process from soma that divides into two long axonal branches, one that acts as dendrite in periphery
Sensory neurons
What are characteristics of the cell body of a neuron?
Large euchromatic nucleus
Prominent nucleolus
Nissl bodies- thick rER and ribosomes
Prominent golgi apparatus
What is the landmark to distinguish between an axon and a dendrite?
Axon hillock - lacks large cytoplasmic organelles
Where is an AP generated?
Axon initial segment - between axon hillock and beginning of myelin sheath
What are the types of synapses?
Axosomatic - axon to soma
Axoaxonic - axon to axon
Axodendritic - axon to dendrites
What are the two types of receptors found in synaptic clefts?
NT-gated channels
G-protein coupled receptor
What are general functions of neuroglia?
Physical support and protection for neurons
Insulation for nerve soma and processes - facilitates rapid transmission of nerve impulses
Repair of neuronal injury
Regulation of internal fluid environment of CNS
Clearance of NTs from synaptic clefts
Metabolic exchange between the vascular system and the neurons of the nervous system
What demyelinating disease affects the PNS?
Guillain-Barre syndrome
What causes Guillain-Barre syndrome?
T-cell mediated immune response against myelin
What demyelinating disease affects the CNS?
Multiple sclerosis
What causes MS?
Autoimmune
What are the two types of astrocytes?
Protoplasmic - gray matter
Fibrous - white matter
Where is the blood-CSF barrier formed by ependymal cells located?
In the choroid plexuses of each ventricle in the brain and in spinal canal
