Test 1 Study Guide Part 2 Flashcards
PNS includes:
- Cranial nerves, and spinal nerves
What are brain tumors in adults normally composed off? Why?
Neuroglia/glial cells
Because these cells are still dividing unlike most neurons.
General term for dendrites and axons:
Processes (extension of the cell body)
Function of neuron body/features of interest:
Metabolic center of the cell, Nissl bodies (rough ER) are localized here and in some large dendrites, they generate proteins for the cell.
A cluster of cell bodies in the CNS Is called:
A cluster of cell bodies in the PNS Is called:
Nuclei
Ganglia
Axonal collaterals:
Axonal collaterals:
extensions/splits which break off from the original axon. An axon can have as many as 200 or more Axon collaterals (collaterals can split further, innervating as many as 30 - 60 thousand neurons).
Three types of neurons
Sensory/afferent neurons:
Motor/efferent neurons:
Interneurons/association neurons:
What is the function of associative/interneurons:
They are located entirely within the CNS and serve to associate or integrate functions of the nervous system (they do all processing)
What are the two broad class of motor/efferent neurons and what do they do:
- Somatic: Regulates skeletal muscles, voluntary and involuntary
- Autonomic: Smooth muscle, cardiac muscle, glands
What are the two subdivisions of autonomic motor neurons and what do they do:
Sympathetic: Generally speeds up activities
Parasympathetic: Generally slows activities
What is the significance of autonomic ganglia and their control centers?
Autonomic ganglia: house the cell bodies of the neurons which innervate the autonomic system
Control centers: Autonomic ganglia interact with neurons which are housed in the autonomic nervous system to compose the autonomic nervous system (and make decisions as to what it should do)
Locations of the following:
- pseudounipolar neurons:
- Bipolar neurons:
- Multipolar neurons:
pseudounipolar neurons:
- Sensory neurons are pseudounipolar (synapse with brain or spinal cord)
Bipolar neurons:
- Retina of the Eyes
Multipolar neurons:
- Most common types (multiple dendrites one axon)
A bundle of axons in the CNS is called:
A bundle of axons in the PNS is called:
Tract
Nerve
Neuroglial cells of the PNS:
Satellite cells/ganglionic gliocytes: Schwann cells (neurolemmocytes):
Neuroglial cells of the CNS:
Oligodendrocytes
Astrocytes
Ependymal cells
Microglial
What makes microglial cells unique?
Derived from a hematopoietic cell line (they come from embryonic yolk sack and migrate to the developing neural tube)
How are microglia different from macrophages, how are they the same?
Because macrophages come from monocytes formed in the bone marrow.
They are the same because both are of a myeloid origin (gives rise to RBCs, many immune cells, monocytes and macrophages)
Microglial resting through activation:
Resting state: they have many processes extended probing for damage or foreign stimuli.
Infection, trauma or an altered state leads to:
- Development of amoeboid in shape
- Phagocytic motile cells
- Follow chemokines, remove damaged dendrites, axon terminals, myelin, and other debris
- Release anti-inflamatory chemokines
- Kill exogenous pathogens
What are the dangers of active microglial cells?
Overactive microglial cell can release free radicals that contribute to neurodegenerative disease.
Why are satellite cells also called ganglionic gliocytes?
Ganglionic gliocytes remove waste and give nutrients to neurons. Since the soma, the metabolic center of the cells are located in the ganglions (n the PNS) the sattelite cells are also localized there. thus ganglionic. Gliocytes is likely because they are small glial cells.