Histology of the CNS Flashcards
(25 cards)
What are the three constituent parts of the brain?
Cerebrum, Cerebellum, and Brain Stem.
How is the brain suborganized?
Into gray matter and white matter.
Distinguish between gray matter and white matter in the brain.
Gray Matter:
Outer covering (cortex).
Contains nerve cell bodies, axons, dendrites, and central glial cells.
Nuclei are islands of gray matter.
Contains more cells per unit area, largely nerve cell bodies.
Organized into 6 layers based on the arrangement of cells and fibers.
White Matter:
Inner core (medulla).
Contains axons of nerve cells, blood vessels, and associated glial cells.
Axons form tracts traveling from one part of the nervous system to another.
Contains fewer cells per unit area, largely neuroglial cells
List the cortical neuron types found in the cerebrum.
Pyramidal cells, Stellate (granule) cells, Cells of Martinotti, Fusiform cells, and Horizontal cells of Cajal.
What is neuropil?
Neuropil is a meshwork of axonal, dendritic, and glial processes associated within gray matter.
Describe the organization of gray and white matter in the brain stem.
The brain stem is not clearly separated into regions of gray and white matter. Cranial nerve nuclei are islands of gray matter surrounded by some distinct tracts of white matter. In areas of reticular formation, the distinction between gray and white matter is less evident.
Name the different parts of the brain stem.
Midbrain, Pons, and Medulla Oblongata.
What is the general organization of gray and white matter in the spinal cord?
The spinal cord has both gray matter and white matter
What are the peripheral neuroglia and their functions?
Schwann Cells: Myelination.
Satellite Cells: Control neuronal microenvironment, provide electrical insulation, and facilitate pathway metabolic exchanges.
What are the central neuroglia and their functions?
Oligodendrocytes: Myelin formation and maintenance.
Astrocytes: Physical and metabolic support.
Microglia: Phagocytic.
Ependymal cells: Line ventricles and the central canal.
What are the components of the CNS overview related to protection?
Bone, Meninges, and CSF (Cerebrospinal Fluid).
Which specific glial cell type is responsible for myelin formation and maintenance in the Central Nervous System (CNS)?
Oligodendrocytes.
What are the key cellular components found in gray matter?
Nerve cell bodies, axons, dendrites, and central glial cells.
What is the primary histological difference between gray matter and white matter in the brain, in terms of cellular composition?
Gray matter contains more nerve cell bodies, while white matter primarily contains axons and neuroglial cells.
The cerebral cortex is organized into how many layers, and what is this organization based on?
Six layers, based on the arrangement of cells and fibers.
In the brain, what are “nuclei” in the context of gray matter?
Islands of gray matter.
What is the major difference in cell density between gray and white matter in the cerebrum?
Gray matter contains more cells per unit area, while white matter contains fewer cells per unit area.
What is a common clinical scenario related to the substantia nigra, which is located in the midbrain?
Parkinson’s Disease.
Which type of neuron is explicitly listed as a cortical neuron type in the cerebrum and is often emphasized due to its distinctive shape?
Pyramidal cells.
What is the function of astrocytes in the CNS?
Physical and metabolic support.
