Histology of Nervous Tissue Exercise 17
Nervous System Figure 11.1
Histology of Nerve Tissue The two principal cell types of the nervous system are: Neurons – excitable (irritable) cells that transmit electrical signals Supporting cells (Neuroglia) – cells that surround and wrap neurons
Neurons (Nerve Cells) Figure 11.4b
Myelin Sheath and Neurilemma: Formation PLAY InterActive Physiology ®: Nervous System I, Anatomy Review, page 10 Figure 11.5a–c
Regions of the Brain and Spinal Cord White matter – dense collections of myelinated fibers Gray matter – mostly soma and unmyelinated fibers http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/Lab9.htm http://www.brainu.org/bu2000.html
Comparison of Structural Classes of Neurons Table 11.1.2
Classification by Function Sensory (afferent) – carry impulse from external and internal environments to CNS Motor (efferent) – carry impulse from CNS to effector organ Interneurons (associative) –neurons between pathways connecting sensory and motor neurons Secondary neurons