Unit 3: Modules 9-11 Flashcards
A nerve cell, the basic building block of the nervous system
Neuron
The part of the neuron that contains the nucleus, the cell’s life-support center
Cell Body (soma)
A neuron’s often bushy, branching extensions, that receive and integrate messages, conducting impulses toward the cell body
Dendrites
The neuron extension that passes messages through its branches to other neurons or to muscles or glands
Axon
A fatty tissue layer that segmentally encases the axons of some neurons, enables vastly greater transmission speed as neurons hop from one node to the next
Myelin Sheath
Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Glial Cells
A neural impulse, a brief electronically charge that travels down an axon
Action Potential
The level of stimulation required to trigger a neural impulse
Threshold
In neural processing, a brief resting pause that occurs after neuron has fired, subsequent action potentials cannot occur until the axon returns to its resting state
Refractory Period
A neuron’s reaction of either firing (with a full-strength response) or not firing
All-or-none-response
The junction between the axon tip of the sending neuron and the dendrite or cell body or receiving neuron. The tiny gap at this junction is called:
Synapse or synaptic cleft
Chemical transmitter that crosses the synaptic gap between neurons, when released by sending neurons, they travel across the synapse and bind to receptor sites on the receiving neuron, influencing whether that neuron will generate a neural impulse
Neurotransmitter
Neurotransmitter’s reabsorption by the sending neuron
Reuptake
Natural, opiate-like neurotransmitters linked to pain control and to pleasure, “morphine-within”
Endorphins
Molecule that increases a neurotransmitter’s action
Agonist
Molecule that inhibits or blocks a neurotransmitter’s action
Antagonist
The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Nervous System
The brain and spinal cord
Central Nervous System (CNS)
The sensory and motor neurons that connect the central nervous system to the rest of the body
Peripheral Nervous System (PNS)
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs
Nerves
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
Sensory (afferent) Neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Motor (efferent) Neurons
Neurons within the brain and spinal cord, communicate internally and process information between sensory inputs and motor outputs
Interneurons
Division of the peripheral nervous system that controls the glands and muscles of internal organs (ex: the heart) sympathetic - arouses parasympathetic - calms
Autonomic Nervous System
