photo.jpg

## Neurons * Neurons are the excitable, impulse-conducting cells that perform the work of the nervous system. * Neuroglia protect the neurons. ## Neuroglia * Also called glial cells, neuroglia are the supportive cells of the nervous system. * Glia means "Glue". ### Cell type * **Neuroglia of C...

## Neurons * Neurons are the excitable, impulse-conducting cells that perform the work of the nervous system. * Neuroglia protect the neurons. ## Neuroglia * Also called glial cells, neuroglia are the supportive cells of the nervous system. * Glia means "Glue". ### Cell type * **Neuroglia of CNS** * Oligodendrocytes: form myelin sheath in the brain and spinal cord; speed signal conduction * **Neuroglia of PNS** * Schwann Cells: Form myelin sheath around nerves in PNS, form neurilemma ## Blood-brain Barrier * Feet of the astrocytes join with the endothelial cells lining the walls of capillaries to create a semi-permeable membrane. * The BBB exists throughout the brain allows small molecules to diffuse across to the brain but blocks larger molecules. * This helps protect the brain form foreign substances. * Also prevents most medications from reaching brain tissue making treating disorders of the brain challenging ## Life Lesson: Gliomas * Gliomas are highly malignant and grow rapidly. * Because of the BBB. Only treatment is surgery and radiation ## Neurons * Nerve cells are called neurons and handle the nervous system's role of communication. ### Three classes of Neurons * **Sensory Neurons** (afferent) detect stimuli such as touch, pressure, heat, cold, or chemicals and then transmit information about the stimuli to the CNS.