| A | B |
|---|
| Central Nervous system | Group of organs that consists of the brain and spinal cord. |
| Peripheral Nervous system | Group of organs that consists of the nerves that connect the central nervous system to other body parts. |
| Sensory Function | Located at the end of peripheral nerves and are specialized to gather information by detecting changes that occur inside and outside the body. |
| Integrative Function | When signals in the form of nerve impulses are brought together creating a sensation;conscious or subconscious decisions are made. |
| Motor Function | Employ peripheral nerves, which carry impulses from the central nervous system to responsive parts called effectors. |
| Neuron | The structural and functional units of the nervous system and are specialized to react to physical and chemical changes. |
| Cell Body | Contains a mass of granular cytoplasm, a cell membrane, and various other organelles usually found in cells. |
| Neurofibrils | A network of fine threads which extend into the nerve fibers. |
| Nissl Bodies | Membranous sacs scattered throughout the cytoplasm which are similar to rough ER in other cells. |
| Dendrites | Short and highly branched nerve fibers that provide the main receptive surfaces of the neuron to which fibers from other neurons communicate. |
| Axons | Nerve fibers that are specialized to conduct nerve pulses away from the cell body. |
| Schwann Cells | Large axons of peripheral nerves commonly enclosed in sheaths of neuroglial cells. |
| Myelin | A lipoprotein that forms a myelin sheath on the outside of an axon. |
| Nodes of Ranvier | Narrow gaps in the myelin sheath between adjacent Schwann cells. |
| Astrocytes | Commonly found between nervous tissue and blood vessels; regulate the concentrations of nutrients and ions within the nervous tissue. |
| Oligodendrocytes | Function in the formation of myelin within the brain and the spinal cord. |
| Microglial cells | Scattered throughout the CNS, where they help support neurons and phagocytize bacterial cells and cellular debris. |
| Ependymal cells | Covers specialized brain parts and forms the inner linings that enclose spaces within the brain and spinal cord. |
| Neurilemma | Sheath on the outside of nerve fibers due to the presence of Schwann cells. |
| Polarization | The development of an electrical charge on the surface of a membrane. |
| Depolarization | The loss of an electrical charge on the surface of a membrane. |
| Resting potential | The difference in electrical charge between the inside and outside of an undisturbed nerve cell membrane. |
| Action potential | The sequence of electrical changes occurring when a nerve cell membrane is exposed to a stimulus that exceeds its threshold. |
| All or none response | A phenomenon in which a muscle fiber contracts completely when it is exposed to a stimulus of threshold strength. |
| Synapse | The junction between the axon end of one neuron and the dendrite or cell body of another neuron. |
| Neurotransmitter | A chemical substance secreted by the terminal end of an axon that stimulates a muscle fiber contraction or an impulse in another neuron. |
