VI - Nervous Tissue Flashcards
Most important histopathologic indicator of CNS injury
gliosis
Functional and structural unit of the CNS, classified according to neurites or size
neuron
Excitable cells that are specialized for the reception of stimuli and conduction of nerve impulse
neuron
Connective tissue of the CNS, non-excitable, structural, protective
glial cells
Neurons: 1 axon that divides into a peripheral and a CNS branch, 0 dendrites, posterior root ganglia, cranial nerves
unipolar/pseudounipolar
Neurons: 1 axon, 1 dendrite, vestibular, cochlear ganglia, retinal ganglia, olfactory mucosa
bipolar
Neurons: 1 axon, ≥ 2 dendrites, most of CNS
multipolar
Neurons: no true axon, many dendrites, do not produce action potentials, regulate electrical changes of adjacent neurons
anaxonic
Neurons: receive stimuli from receptors
sensory / afferent
Neurons: sends impulses to effector organs
motor / efferent
Neurons: under voluntary control, innervate skeletal muscle
somatic motor
Neurons: involuntary, innervate glands, cardiac muscle and smooth muscle
autonomic motor
Neurons: establish relationships among other neurons
interneurons
Neurons: single long axon, fiber tracts of the brain and spinal cord, peripheral nerves, motor cells of the spinal cord
golgi type 1 cells
Neurons: single short axon, cerebral & cerebellar cortex
golgi type 2 cells
Neurons: conduct nerve impulse towards the cell body
dendrites
Neurons: contains the cell activities
body
Neurons: small conical elevation on the cell body
axon hillock
Neurons: conduct impulses away from the cell body
axon
Neurons: gaps between myelinated segments exposed to the extracellular milieu of the cell
nodes of Ranvier
Neurons: axon terminals, contain neurotransmitter vesicles
synaptic terminals
Neurons: materials are transported to the axons from the cell body, kinesin
Anterograde Axonal Transport
Neurons: transport of nerve growth factor, HSV, tetanus toxin, botulinum toxin, dynein
Retrograde Axonal Transport
What cellular structure is particularly increased in neurons
rough endoplasmic reticulum
RER in the CNS is in the form of
Nissl substance
Composed of stacked RER
Nissl substance
Phenomenon in fatigue or neuronal damage in which the Nissl substance moves and becomes concentrated in the periphery
chromatolysis
Stain used to localize Nissl substance
Aniline Stain
Major inhibitory NT in the spinal cord
glycine
Major inhibitory NT in the brain
GABA
Major excitatory NT in the CNS
glutamate
NT depleted in Parkinson’s disease
dopamine
NT in excess in Schizophrenia
dopamine
NT that plays a role in depression, anxiety and panic attacks
serotonin, norepinephrine
NT abundant in the raphe nuclei of the brain
serotonin
Maintains CNS hemostasis, protect and surround neurons and hold them in place
neuroglia
Provides oxygen and nutrients to neurons, insulates neurons from each other, destroys and removes pathogens in the CNS
neuroglia
Neuroglia: structural and metabolic support, BBB, repair processes, white matter
astrocytes (fibrous cell)
Neuroglia: structural and metabolic support, BBB, repair processes, gray matter
astrocytes (protoplasmic)
Neuroglia: along myelinated nerves and surrounding neuron cell bodies, form myelin in CNS
oligodendrocytes
Neuroglia: peripheral nerves, form myelin in PNS
Schwann cells (neurolemmocyte)
Neuroglia: scattered throughout CNS, phagocytic action
microglia
Neuroglia: peripheral ganglia, structural and metabolic support for neuronal cell bodies
satellite cells
Neuroglia: lines the ventricles and central canals, circulation and absorption of CSF
ependyma (ependymyocytes)
Neuroglia: lines the floor of the 3rd ventricle, transport CSF to the hypophyseal portal system
ependyma (tanycytes)
Neuroglia: line the choroidal plexus, production of CSF
ependyma (choroidal epithelial cells)
Supporting framework, project foot processes (perivascular feet) in the capillaries which contribute to the BBB, play a role in the metabolism of NT
astrocytes
Buffer the potassium concentration of the CNS form glial scars after injury, undergo hypertrophy and hyperplasia after injury, contain Glial Fibrillary Acidic Protein (GFAP)
astrocytes
Most common primary CNS tumor in children
astrocytoma
Largest neuroglial cells
astrocytes
Myelinate axons in the PNS
Schwann cells
Neuroglia: originate from the mesoderm
microglia
Neuroglia: line the ventricular cavities
ependymal cells
Neuroglia: have numerous processes with expanded vascular end feet or pedicles which attach to the wall of the capillaries
astrocytes
Neuroglia: Part of the mononuclear phagocytic system
microglia
Forms glial scars
astrocytes
Modified type of ependymal cells in the hypothalamus
tanycytes
Neuroglia: participate in BBB
astrocytes
Neuroglia: myelinate axons in the CNS
oligodendrocytes
Neuroglia: undergo hyperplasia and hypertrophy in reaction to CNS injury
astrocytes
Neuroglia: ciliated cells which help move CSF through ventricles
ependymal cells
Degeneration of oligodendrocytes results in
multiple myeloma
Limiting layer of perivascular astrocytic feet, tight junction betweet endothelial cells of capillaries
Blood-Brain Barrier
Tight junctions between choroid epithelial cells, endothelial cells of capillaries
Blood-CSF Barrier