Term | Definition |
Central Nervous System | Includes the brain and spinal cord. |
Peripheral Nervous System | Includes spinal nerves to carry impulses to and from the spinal cord and cranial nerves to carry impulses to and from the brain. |
Sensory (afferent) Division | Includes somatic sensory fibers and visceral sensory fibers. |
Motor (efferent) Division | Carries impulses from the CNS to organs, muscles and glands. |
Sense Organs | Skin, skeletal muscles, joints, and organs. |
Somatic Division | Voluntarily controlled like skeletal muscles. |
Autonomic Division | Involuntarily controlled like the heart muscle. |
Parasympathetic Division | Referred to as the "Resting and Digesting" system. |
Sympathetic Division | Referred to as the "Fight or Flight" system |
Astrocyte | *Abundant, star shaped. |
Microglial cell | *Spider-like phagocyte. |
Ependymal cells | *Lines the cavity of the brain and spinal cord. |
Oligodendrocytes | *Produces fatty insulating coverings called myelin sheaths. |
Satellite cells | *Act as protective, cushioning cells. |
Schwann cells | *Form myelin sheaths around nerve fibers. |
Nucleus | Control center of the cell body of the neuron. |
Mitochondrion | The energy providing organelle. |
Dendrite | convey incoming messages toward the cell body. |
Cell body | Part of the neuron that contains organelles surrounded by cytoplasm. |
Nissl substance | Rough endoplasmic reticulum |
Axon hillock | Cone like region |
Neurofibrils | Sometimes called the "neuron husk". |
Axon | carry messages away from the cell body. |
Collateral branch | An occasional protrusion along an axon. |
Node of Ranvier | Gaps formed from the individual Schwann cells |
Axon terminal | End of the axon |