nervous system part 1 Flashcards
(17 cards)
What are the two main divisions of the nervous system?
Central nervous system (CNS) and Peripheral nervous system (PNS)
What are the two types of cells in nervous tissue?
Neuroglia and Neurons
What is the role of neuroglia?
Protect and support neurons, segregate and insulate neurons, secrete chemicals to guide young neurons, and promote neuron health and growth.
What are the types of neuroglia in the CNS?
Astrocytes, Microglia, Ependymal cells, Oligodendrocytes
What is the function of astrocytes?
Provide support, cover capillaries, and regulate the chemical environment.
What do ependymal cells do?
Line the central cavities of the brain and spinal cord and produce and circulate cerebrospinal fluid (CSF).
What is the function of oligodendrocytes?
Wrap around neuron fibers and form myelin sheaths.
What are the types of neuroglia in the PNS?
Satellite cells and Schwann cells
What do Schwann cells do?
Surround nerve fibers and form myelin sheath.
What are the classifications of neurons?
Bipolar neurons, Unipolar neurons, Multipolar neurons
How do neurons communicate?
Through action potentials and chemical neurotransmitters.
What is an action potential?
A sequence of rapidly occurring events that decrease and reverse the membrane potential and then restore it to the resting state.
What are the phases of an action potential?
A depolarizing phase and a repolarizing phase.
What types of voltage-gated channels are involved in action potentials?
Na+ gated and K+ gated channels.
What happens during axonal degeneration in the PNS?
Injured axon regenerates.
What happens during axonal degeneration in the CNS?
Injured axon cannot regenerate.
What are some factors that inhibit axon regeneration in the CNS?
Oligodendrocytes and microglia cannot remove myelin quickly, and myelin debris contains inhibitors of axon regeneration.
