Exam 3 Review:  Chapter 11:  Gross Anatomy of the Nervous System  

Human Brain, cross-section	Spinal Cord, cross-section

nerve fiber - A threadlike process of a neuron, especially the prolonged axon that conducts nerve impulses.

nerve - A bundle of hundreds or thousands of motor axons and sensory dendrites wrapped in three distinctive layers of connective tissue (epineurium, perineurium, and endoneurium) and being routed to or from a particular peripheral region in the body; these are the major components of the Peripheral Nervous System.

ganglion, ganglia - Small masses of nervous tissue, containing primarily cell bodies of neurons; the terms are appropriate to describe areas in either the Central or Peripheral Nervous Systems.  (Although the term also applies to regions of gray matter in the central nervous system such as the "basal ganglia", this term increasingly refers specifically to collections of cell bodies in the peripheral nervous system.)

tract - A bundle of (usually or mostly myelinated) nerve fibers having a common origin, termination, and function located in the white matter of the CNS.

gray matter - Nerve cell bodies, dendrites, and axon terminals or bundles of unmyelinated axons and neuroglia organized into functional groupings within the Central Nervous System; in the spinal cord, gray matter forms an H-shaped inner core, surrounded by white matter; in the brain a thin outer shell of gray matter (cortex) covers the cerebral hemispheres.  (Additional regions of gray matter are found deep in the brain where the are referred to as nuclei, or with diminishing frequency, ganglia; and additional regions are found within the ganglia of the Peripheral Nervous System.)

white matter - Aggregations of myelinated axons spatially organized into functional tracts within the Central Nervous System or the Peripheral Nervous System.

nucleus, nuclei- Any small mass of nervous tissue gray matter, containing primarily clusters of cell bodies and dendrites of neurons with similar functions, located among the various white matter fiber tracts within the Central Nervous Systems.

Explain:

1. The difference between gray and white matter and what parts of neurons would generally be located in gray versus white matter.