unit 3 Flashcards
biological psychology
the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes
neuron
nerve cell; the basic building block of the nervous system
dendrites
a neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body
axon
the neuron extension that passes messages through its branches to other neurons or to muscles or glands.
myelin sheath
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
action potential
a neural impulse; a brief electrical charge that travels down an axon.
refractory period
a period of inactivity after a neuron has fired. a resting period after orgasm, during which a man cannot achieve another
threshold
the level of stimulation required to trigger a neural impulse.
all or none response
a neuron’s reaction of either firing (with a full strength response) or not firing
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft
neurotransmitters
chemical messengers that cross the synaptic gaps 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
“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure
agonist
a molecule that, by binding to a receptor site, stimulates a response
antagonist
a molecule that, by binding to a receptor site, inhibits or blocks a response
nervous system
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
central nervous system
the brain and spinal cord
peripheral nervous system
all those nerves that lie outside the brain and spinal cord
nerves
bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs.
sensory neurons
neurons that carry incoming information from the sensory receptors to the brain and spinal cord.
motor 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 that communicate internally and intervene between the sensory inputs and motor outputs.
somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles.
autonomic nervous system
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
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 response.
endocrine system
the body’s “slow” chemical communication system; a set of glands 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 glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress
pituitary glands
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
lesion
tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.
electroencephalogram
an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp
CT (computed tomography) scan
a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure.
PET (position emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task