Module 9: Fundamentals of the Nervous System Flashcards
Cell body
Also called perikaryon or soma
Contains the usual organelles except centrioles (needed for mitosis, therefore cannot replicate)
Contains Nissl bodies
Nissl bodies
Unique to neurons
Specialized layers of rough ER
Synthesize neurofibrils and microtubules for material transport within the cell
Interneurons
Also called association neurons
Lie entirely within the central nervous system
Receive input from sensory (afferent) neurons and communicate with one another or with motor (efferent) neurons
Neuroglia
Also called glia
Do not conduct nerve impulses (stimuli)
Support, nourish, and protect the neurons
Capable of mitosis
Six types of neuroglia
Astrocytes (CNS) Oligodendrocytes (CNS) Microglia (CNS) Ependymal cells (CNS) Schwann Cells (Neurolemmocytes) (PNS) Satellite cells (PNS)
Nerve
Bundle of nerve cell fibers (axons and dendrites) that follow the same path
Usually contains both sensory (afferent) neurons and motor (efferent) neurons
Found only in the PNS
Tract
A bundle of nerve cell fibers
Found only in the CNS
Ganglia
Clusters of neuron cell bodies
Found only in the PNS
Nuclei
Clusters of neuron cell bodies
Found only in the CNS
Neurolemmocytes (Schwann cells)
Form myelin sheath in the PNS
Neurolemma
Plasma membrane of neurolemmocytes
Responsible for nerve regeneration
Oligodendrocytes
Form myelin sheath in the CNS
No plasma membrane
Acetylcholine (ACh)
Only neurotransmitter released between neurons and skeletal muscles
Resting state
ECF - higher Na+ and Cl-
ICF - higher K+ and negatively charged proteins (Pr-)