NeuroScience: Neural and Hormonal Systems Flashcards
neuroplasticity
the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.
biological psychology
the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.
neuron
a nerve cell; the basic building block of the nervous system.
cell body
the part of a neuron that contains the nucleus; the cell’s life-support center.
dendrites
a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.
axon
the segmented neuron extension that passes messages through its branches to other neurons or to muscles or glands.
myelin [MY-uh-lin] sheath
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.
glial cells (glia)
cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.
action potential
a neural impulse; a brief electrical charge that travels down an axon.
threshold
the level of stimulation required to trigger a neural impulse.
refractory period
resting pause after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.
all-or-none response
a neuron’s reaction of either firing (with a full-strength response) or not firing.
synapse [SIN-aps]
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
neurotransmitters
chemical messengers that cross the synaptic gap between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
reuptake
a neurotransmitter’s reabsorption by the sending neuron.
endorphins [en-DOR-fins]
“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure.
agonist
a molecule that increases a neurotransmitter’s action.
antagonist
a molecule that inhibits or blocks a neurotransmitter’s action.
central nervous system (CNS)
the brain and spinal cord.
peripheral nervous system (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
nerves
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs.
sensory (afferent) neurons
neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.
motor (efferent) neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
interneurons
neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.
somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.
autonomic [aw-tuh-NAHM-ik] nervous system (ANS)
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy.
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy.
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk reflex.
endocrine [EN-duh-krin] system
the body’s “slow” chemical communication system; glands and fat tissue that secrete hormones into the bloodstream.
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
adrenal [ah-DREEN-el] glands
a pair of glands that sits just above the kidneys and secretes hormones that help arouse the body in times of stress. (adrenaline)
pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
