Chapter 2 Flashcards
relative and approximate number of neurons and glia in brain:
approx. 80 billion neurons in the brain (75% of which are in the cerebellum!); 1 to 50 times that many glial cells
golgi stain:
shows the whole cell – good for shapes of cells
nissl stain:
shows just soma – good for counting
sensory neurons:
nerve cells that are directly affected by changes in the environment
motor neurons:
cells that transmit neural messages to muscles/glands
oligodendrocytes:
a type of glial cell that forms myelin in the CNS
Schwann cells:
a type of glial cell that forms myelin in the PNS
multiple sclerosis (MS):
literally “many scars” – characterized by the widespread degeneration of myelin
astrocytes:
star-shaped glial cells that form the blood-brain barrier
microglia:
teeny-tiny glia that clean up waste
nerves vs. tracts
nerves are axons in the PNS; tracts are axons in the CNS
ganglia vs. nuclei
ganglia are somas in the PNS; nuclei are somas in the CNS
autonomic nervous system:
the part of the PNS that supplies neural connections to glands and to smooth muscles of internal organs – sympathetic and parasympathetic
cerebral cortex:
outer covering of the cerebral hemispheres, which consist largely of cell bodies and their branches
dorsal direction:
toward or at the back