11.1 Flashcards
Neuron
A nerve cell that is capable of conducting nerve impulses.
Neural signalling
The reception, transmission, and integration of nerve impulses by neurons, and the response to these impulses.
Afferent neuron
A neuron that carries impulses from sensory receptors to the central nerve out system; also called sensory neuron.
Interneuron
A local circuit neuron of the central nervous system that relays impulses between afferent (sensory) and efferent (motor) neurons.
Efferent neuron
A neuron that carries impulses from the central nervous system to skeletal muscles; also known as a motor neuron.
Dendrite
A projection of cytosol that carries signals toward the nerve cell body.
Axon
An extension of cytosol that carries nerve signals away from the nerve cell body.
Glial cell
A non-conducting cell that is important for the structural support and metabolism of nerve cells.
Myelin sheath
An insulted covering over the axon of a nerve cell.
Node of ranvier
A regularly occurring gap between sections of myelin sheath along the axon.
Central nervous system (CNS)
The body’s coordinating center for mechanical and chemical actions; made up of the brain and spinal cord.
Peripheral nervous system
All parts of the nervous system, excluding the brain and spinal cord; relay information between the central nervous system and other parts of the body.
Afferent system
The component of the peripheral nervous system that receives input through receptors and transmits the input to the central nervous system.
Efferent system
The component of the peripheral nervous system that carries signals away to the effector (muscles and glands).
Somatic system
A subdivision of the efferent system (within the PNS); composed of efferent (motor) neurons that carry signals to skeletal muscles in response to external stimuli.
Autonomic system
A subdivision of the efferent system (within the PNS); regulates the internal environment.
Autonomic system
A subdivision of the efferent system (within the PNS); regulates the internal environment.
Sympathetic division
One of the two subdivisions of the autonomic nervous system; increases energy consumption and prepares the body for action.
Parasympathetic
One of two subdivisions of the autonomic nervous system; stimulates body activities that acquire and conserve energy.
Neural circuit
The coordination of the receptor, afferent neuron, interneuron, efferent neuron, and effector in response to a stimulus.
Reflex arc
A neural circuit that travels through the spinal cord but does not require the coordination of the brain; allows for reflex action.
