Chapter2 Flashcards
acetylcholine (ACh)
The neurotransmitter responsible for motor control at the junction between nerves and muscles; also involved in mental processes such as learning, memory, sleeping, and dreaming.
action potential
The neural impulse that passes along the axon and subsequently causes the release of chemicals from the terminal buttons.
agonist
Any drug that enhances the actions of a specific neurotransmitter.
all-or-none principle
The principle whereby a neuron fires with the same potency each time, although frequency can vary; it either fires or not-it cannot partially fire.
amygdala
A brain structure that serves a vital role in our learning to associate things with emotional responses and in processing emotional information.
antagonist
Any drug that inhibits the action of a specific neurotransmitter.
autonomic nervous system (ANS)
A major component of the peripheral nervous system; it regulates the body’s internal environment by stimulating glands and by maintaining internal organs such as the heart, gall bladder, and stomach.
axon
A long narrow outgrowth of a neuron by which information is transmitted to other neurons.
basal ganglia
A system of subcortical structures that are important for the initiation of planned movement.
brainstem
A section of the bottom of the brain, housing the most basic programs of survival, such as breathing, swallowing, vomiting, urination, and orgasm.
Broca’s area
The left frontal region of the brain, crucial for the production of language.
cell body
In the neuron, where information from thousands of other neurons is collected and processed.
central nervous system (CNS)
The brain and spinal cord.
cerebellum
A large, convoluted protuberance at the back of the brainstem, essential for coordinated movement and balance.
cerebral cortex
The outer layer of brain tissue, which forms the convoluted surface of the brain.
chromosomes
Structures within the cell body that are made up of genes.
dendrites
Branchlike extensions of the neuron that detect information from other neurons.
dizygotic twins
Twin siblings who result from two separately fertilized eggs (i.e., fraternal twins).
dominant gene
A gene that is expressed in the offspring whenever it is present.
dopamine
A monoamine neurotransmitter involved in reward, motivation, and motor control.
endocrine system
A communication system that uses hormones to influence thoughts, behaviors, and actions.
endorphins
A neurotransmitter involved in natural pain reduction and reward.
epinephrine
The neurotransmitter responsible for adrenaline rushes, bursts of energy caused by its release throughout the body.
frontal lobes
The region at the front of the cerebral cortex concerned with planning and movement.
GABA (gamma-aminobutyric acid)
The primary inhibitory transmitter in the nervous system.
gene
The unit of heredity that determines a particular characteristic in an organism.
genotype
The genetic constitution determined at the moment of conception.
glutamate
The primary excitatory transmitter in the nervous system.
gonads
The main endocrine glands involved in sexual behavior: in males, the testes; in females, the ovaries.
heritability
A statistical estimate of the variation, caused by differences in heredity, in a trait within a population.
hippocampus
A brain structure important for the formation of certain types of memory.
hormones
Chemical substances, typically released from endocrine glands, that travel through the bloodstream to targeted tissues, which are subsequently influenced by the hormones.
hypothalamus
A small brain structure that is vital for temperature regulation, emotion, sexual behavior, and motivation.
interneurons
One of the three types of neurons, these neurons communicate only with other neurons, typically within a specific brain region.
monozygotic twins
Twin siblings who result from one zygote splitting in two and therefore share the same genes (i.e., identical twins).
motor neurons
One of the three types of neurons, these efferent neurons direct muscles to contract or relax, thereby producing movement.
myelin sheath
A fatty material, made up of glial cells, that insulates the axon and allows for the rapid movement of electrical impulses along the axon.
neuron
The basic unit of the nervous system; it operates through electrical impulses, which communicate with other neurons through chemical signals. Neurons receive, integrate, and transmit information in the nervous system.
neurotransmitter
A chemical substance that carries signals from one neuron to another.
nodes of Ranvier
Small gaps of exposed axon, between the segments of myelin sheath, where action potentials are transmitted.
norepinephrine
The neurotransmitter involved in states of arousal and awareness.
occipital lobe
A region of the cerebral cortex, at the back of the brain, important for vision.
parasympathetic division of ANS
A division of the autonomic nervous system; it returns the body to its resting state.
parietal lobe
A region of the cerebral cortex, in front of the occipital lobes and behind the frontal lobes, important for the sense of touch and of the spatial layout of an environment.
Parkinson’s disease
A neurological disorder that seems to be caused by dopamine depletion, marked by muscular rigidity, tremors, and difficulty initiating voluntary action.
peripheral nervous system (PNS)
All nerve cells in the body that are not part of the central nervous system. The PNS includes the somatic and autonomic nervous systems.
phenotype
Observable physical characteristics that result from both genetic and environmental influences.
pituitary gland
Located at the base of the hypothalamus; the gland that sends hormonal signals controlling the release of hormones from endocrine glands.
plasticity
A property of the brain that allows it to change as a result of experience, drugs, or injury.
prefrontal cortex
A region of the frontal lobes, especially prominent in humans, important for attention, working memory, decision making, appropriate social behavior, and personality.
receptors
In neurons, specialized protein molecules, on the postsynaptic membrane, that neurotransmitters bind to after passing across the synaptic cleft.
recessive gene
A gene that is expressed only when it is matched with a similar gene from the other parent.
resting membrane potential
The electrical charge of a neuron when it is not active.
restructuring
A new way of thinking about a problem that aids its solution.
reuptake
The process whereby a neurotransmitter is taken back into the presynaptic terminal buttons, thereby stopping its activity.
sensory neurons
One of the three types of neurons, these afferent neurons detect information from the physical world and pass that information along to the brain.
serotonin
A monoamine neurotransmitter important for a wide range of psychological activity, including emotional states, impulse control, and dreaming.
somatic nervous system
A major component of the peripheral nervous system; it transmits sensory signals to the CNS via nerves.
substance
P A neurotransmitter involved in pain perception.
sympathetic division of ANS
A division of the autonomic nervous system; it prepares the body for action.
synapse, or synaptic cleft
The site for chemical communication between neurons, which contains extracellular fluid.
synesthesia
Cross-sensory experience (in which, e.g., a visual image has a taste).
temporal lobes
The lower region of the cerebral cortex, important for processing auditory information and for memory.
terminal buttons
Small nodules, at the ends of axons, that release chemical signals from the neuron to the synapse.
thalamus
The gateway to the brain; it receives almost all incoming sensory information before that information reaches the cortex.
