12.3 Short Answer Questions
1) The ________ matter of the spinal cord forms a butterfly-shaped structure.
2) ________ is a progressive disease that destroys patches of myelin in both the brain and spinal cord.
3) ________ form the myelin sheaths in the brain and spinal cord.
4) ________ is the term for the previously held belief that fully differentiated neurons could not divide.
5) ________ are chemicals that control the growth of newly forming neurons.
6) Cytoplasm, organelles, and neurotransmitters move through the cytoplasm of the axon by a mechanism called ________.
7) White matter is white in color because of ________.
8) A(n) ________ is a medical specialist in the study of the nervous system and its disorders.
9) Nearly all somatic sensory neurons are of this type, based on the classification of the type and number of processes.
10) Nearly all motor neurons are of this type, based on the classification of the type and number of processes.
11) ________ are the neuroglial cells with cilia.
12) These neurons reside only in the CNS and connect motor and sensory neurons.
13) Neurotransmitters are found packaged inside ________ in the axon terminal.
14) ________ neurons develop from neural crest cells.
15) The simplest of all reflexes is the ________ reflex.