Chapter 4; Textbook Flashcards
Define Central Nervous System?
The portion of the nervous system consisting of the brain and spinal cord.
What is the Spinal Cord?
A collection of neurons and supportive tissues running from the base of the brain down the centre of the back, protected by a column of bones (the spinal cord).
Define Peripheral Nervous System?
All portions of the nervous system outside the brain and spinal cord; it includes sensory and motor nerves.
Define Somatic Nervous System?
The subdivision of the peripheral nervous system that connects to sensory receptors and to skeleton muscles; sometimes called the skeletal nervous system.
What is the Autonomic Nervous System?
The subdivision of the peripheral nervous system that regulates the internal organs and glands.
What is the Sympathetic Nervous System?
The subdivision of the autonomic nervous system that mobilizes bodily resources and increases the output of energy during emotion and stress.
What is the Parasympathetic Nervous System?
The subdivision of the autonomic nervous system that operates during relaxed states and that conserves energy.
What is a neuron?
A cell that conducts electrochemical signals; the basic unit of the nervous system; also called a nerve cell.
What are glia?
Cells that support, nurture, and insulate neurons, remove debris when neurons die, enhance the formation and maintenance of neural connections, and modify neuronal functioning.
What are dendrites?
A neuron’s branches that receive information from other neurons and transmit it toward the cell body.
What is the cell body?
The part of the neuron that keeps it alive and determines whether or not it will fire.
What is the axon?
A neuron’s extending fibre that conducts impulses away from the cell body and transmits them to other neurons.
What is the myelin sheath?
A fatty insulation that may surround the axon of a neuron.
What is a nerve?
A bundle of nerve fibres (axons and sometimes dendrites) in the peripheral nervous system.
What is neurogenesis?
The production of new neurons from immature stem cells.
What are stem cells?
Immature cells that renew themselves and have the potential to develop into mature cells; given encouraging environments, stem cells from early embryos can develop into any cell types.
What is the synapse?
The site where transmission of a nerve impulse from one nerve cell to another occurs; it includes the axon terminal, the synaptic cleft, and receptor sites in the membrane of the receiving cell.
What is an action potential?
A brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated; it serves to produce an electrical impulse.
What is a neurotransmitter?
A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron.
What is plasticity?
The brain’s ability to change and adapt in response to experience - for example, by reorganizing or growing new neural connections.
What are endorphins?
Chemical substances in the nervous system that are similar in structure and action
