Unit 1: Biological Bases of Behavior Flashcards
neurons
nerve cells; the basic building blocks of the nervous system
glial cells
cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning, thinking, and memory
heredity
the genetic transfer of characteristics from parents to offspring
nature
the innate, presumably genetically determined, characteristics and behaviors of an individual. In psychology, the characteristics most often and traditionally associated with nature are temperament, body type, and personality
nurture
the totality of environmental factors that influence the development and behavior of a person, particularly sociocultural and ecological factors such as family attributes, parental child-rearing practices, and economic status
genetic predisposition
a tendency for certain traits to be inherited, including physical and mental conditions and disorders
evolutionary perspective
the study of the evolution of behavior and the mind, using principles of natural selection
natural selection
the principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations
eugenics
a social and political philosophy, based loosely on Charles Darwin’s evolutionary theory and Francis Galton’s research on hereditary genius, that seeks to eradicate genetic defects and improve the genetic makeup of populations through selective human breeding
twin studies
research utilizing twins. The purpose of such research is usually to assess the relative contributions of heredity and environment to some attribute. Specifically, twin studies often involve comparing the characteristics of identical and fraternal twins and comparing twins of both types who have been reared together or reared apart
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
autonomic nervous system (ANS)
the part of the peripheral nervous system (PNS) that controls the glands and the muscles of the intestinal organs (such as the heart). Its sympathetic division arouses; its parasympathetic system 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
somatic nervous system (SNS)
the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system
neural transmission
the process by which a signal or other activity in a neuron is transferred to an adjacent neuron or other cell
action potential
a neural impulse, a brief electrical charge that travels down an axon
all-or-nothing principle
a neuron’s reaction of either firing (with a full-strength response) or not firing
depolarization
a reduction in the electric potential across the plasma membrane of a cell, especially a neuron, such that the inner surface of the membrane becomes less negative in relation to the outer surface
refractory period
in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state
resting potential
the electric potential across the plasma membrane of a neuron when it is in the nonexcited, or resting, state
reuptake
a neurotransmitter’s reabsorption by the sending neuron
threshold
the level of stimulation required to trigger a neural impulse
multiple sclerosis
a disease of the central nervous system (brain and spinal cord) characterized by inflammation and multifocal scarring of the protective myelin sheath of nerves, which damages and destroys the sheath and the underlying nerve, disrupting neural transmission
myasthenia gravis
an autoimmune disease in which the body produces antibodies against acetylcholine receptors, causing faulty transmission of nerve impulses at neuromuscular junctions
excitatory neurotransmitters
exert a facilitatory or activating downstream effect on postsynaptic neurons. That is, they depolarize the postsynaptic neurons, resulting in a greater likelihood of an action potential.
inhibitory neurotransmitters
hyperpolarize the postsynaptic neurons—thereby making the intracellular space more negative, and hence, requiring a greater positive charge to overcome—resulting in a smaller likelihood of an action potential
dopamine
a neurotransmitter that influences movement, learning, attention, and emotion; an oversupply can lead to schizophrenia; undersupply can lead to tremors and decreased mobility in Parkinson’s disease
Serotonin
a neurotransmitter that affects mood, hunger, sleep, and arousal. Undersupply linked to depression, Some drugs that raise serotonin levels are used to treat depression
norepinephrine
Helps control alertness and arousal. Undersupply can depress mood
Glutamate
A major excitatory neurotransmitter involved in memory. Oversupply can overstimulate the brain, producing migraines or seizures
GABA
(gamma-aminobutyric acid) A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia.
Endorphins
A neurotransmitter that influences the perception of pain or pleasure. Oversupply with opioid drugs can suppress the body’s natural endorphin supply
Substance P
Involved in pain perception and immune response. Oversupply can lead to chronic pain.
Acetylcholine (ACh)
Enables muscle action, learning, and memory. With Alzheimer’s disease, ACh-producing neurons deteriorate
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
adrenaline
Hormone that increases heart rate, blood pressure, and blood sugar, providing a surge of energy to power our “fight or flight” response.
leptin
a protein, manufactured and secreted by fat cells, that may communicate to the brain the amount of body fat stored and may help to regulate food intake. Leptin receptors have been found in the hypothalamus, and, when they are stimulated, food intake is reduced
ghrelin
a peptide secreted by endocrine cells in the stomach that binds to growth hormone receptors in the hypothalamus and anterior pituitary, stimulating appetite and the release of growth hormone
melatonin
an amine hormone, produced mainly by the pineal gland as a metabolic product of the neurotransmitter serotonin, that helps to regulate seasonal changes in physiology and may also influence puberty. It is implicated in the initiation of sleep and in the regulation of the sleep–wake cycle
oxytocin
a peptide produced in the hypothalamus and released by the posterior pituitary gland into the blood, where it acts as a hormone, or into the central nervous system, where it acts as a neurotransmitter and binds to oxytocin receptors to influence behavior and physiology. Perhaps best known for its role in stimulating contractions of smooth muscle in the wall of the uterus to facilitate labor
psychoactive drug
a chemical substance that alters the brain, causing changes in perceptions and mood
agonist
a molecule that increases a neurotransmitter’s action
antagonist
a molecule that inhibits or blocks a neurotransmitter’s actions
reuptake inhibitors
a substance that interferes with the reabsorption of neurotransmitters by the presynaptic neurons that released them
stimulants
drugs that excite neural activity and speed up body functions
caffeine
stimulant that increases alertness and wakefulness. negative effects include anxiety, restlessness, and insomnia in high doses
cocaine
stimulant increasing arousal and relaxation and sense of well-being; negative effects include cardiovascular stress, suspiciousness, and a depressive crash
depressants
drugs that reduce neural activity and slow body functions
alcohol
depressant with an initial high followed by relaxation and disinhibition. Negative effects can include depression, memory loss, organ damage, impaired reactions
hallucinogens
psychedelic (“mind-manifesting”) drugs that distort perceptions and evoke sensory images in the absence of sensory input
marijuana
a mild hallucinogen that enhances sensation, relief of pain, distortion of time, and relaxation. Negative effects could include impaired learning and memory and increase risk of psychological disorders
opioids
opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety
heroin
depressant that comes with a rush of euphoria and relief from pain. Negative effects can include depressed physiology and loss of natural endorphin function
tolerance
the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect
addiction
an everyday term for compulsive substance use (and sometimes for dysfunctional behavior patterns, such as out-of-control gambling) that continue despite harmful consequences
withdrawal
the discomfort and distress that follow discontinuing an addictive drug or behavior
brain stem
the central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions