Cells of the Nervous System

pages 24-29, 49-56

neurons (nerve cells)

sense detailed changes in the environment, rapidly communicate these changes to other neurons & coordinate the body’s response to this sensation

glia (glial cells)

contribute to brain function by mainly insulating, supporting & nourishing neighboring cells

histology

microscopic study of the structure of tissues

Nissl stain

Franz Nissl used dyes to show individual neurons

Nissl bodies

clumps of material surrounding the nuclei of neurons

cytoarchitecture

arrangement of neurons in different parts of the brain

Golgi stain

soak the brain in silver chromatic solution to make a small percentage of neurons become darkly colored in their entirety

cell body

the central region of the neuron containing the nucleus (also soma/perikaryon)

soma

the central region of the neuron containing the nucleus (also cell body/perikaryon)

perikaryon

the central region of the neuron containing the nucleus (also soma/cell body)

neurites

the projections that come from the soma

axons

a neurite specialized to conduct nerve impulses/action potentials, normally away from the soma

dendrites

a neurite specialized to receive synaptic inputs from other neurons

neuron doctrine

the concept that the neuron is the elementary functional unit of the brain & that neurons communicate with each other by contact, not continuity (Cajal)

cytosol

the watery, salty, potassium-rich fluid inside a cell

organelles

membrane-enclosed structure inside a cell, ex: nucleus, mitochondrion, endoplasmic recticulum & Golgi apparatus

cytoplasm

cellular material continued by the cell membrane

astrocytes

a glial cell in the brain that supports neurons & regulates the extracellular ionic & chemical environment

oligodendroglia

a glial cell that provides myelin in the CNS

schwann cells

a glial cell that provides myelin in the PNS

myelin

membranes wrapping (/sheath) around axons provided by oligodendroglia cells in the CNS & Schwann cells in the PNS

node of ranvier

a space between 2 consecutive myelin sheaths where an axon comes in contact w/the extracellular fluid

microglia

class of nonneural cells in the CNS that have important roles in immunity, phagocytosis, and neural development

ependymal cells

a type of glial cell that provides the lining of the brain’s venticular system