Interaction of Heredity & Environment
This term refers to the genetic and biological influences on human behavior and psychological traits.
What is nature?
Nature refers to inherited genetic and biological influences, while nurture refers to environmental influences.
These branchlike extensions of a neuron receive incoming messages from other neurons.
What are dendrites?
Dendrites receive signals and transmit them toward the cell body.
These chemical messengers cross the synaptic gap and bind to receptors on receiving neurons.
What are neurotransmitters?
Neurotransmitters are released from axon terminals and bind to receptors on target cells.
These chemical substances alter consciousness, mood, perception, or behavior by affecting the central nervous system.
What are psychoactive drugs?
Psychoactive drugs influence brain functioning and may affect thinking, emotions, perception, and behavior.
This term refers to the brain's ability to change and reorganize its neural connections in response to learning, experience, or injury.
What is neuroplasticity?
Neuroplasticity allows the brain to adapt throughout life by strengthening, weakening, or reorganizing neural connections.
These inherited units of DNA carry biological information from parents to offspring and influence traits and behavior.
What are genes?
Genes are segments of DNA that contribute to inherited characteristics.
This long extension of a neuron carries electrical impulses away from the cell body toward other neurons, muscles, or glands.
What is the axon?
The axon carries action potentials away from the cell body.
This neurotransmitter is involved in muscle movement, learning, and memory and is reduced in the brains of many individuals with Alzheimer's disease.
What is acetylcholine (ACh)?
Acetylcholine helps activate skeletal muscles and plays important roles in attention and memory.
Alcohol, benzodiazepines, and barbiturates belong to this category of psychoactive drugs, which generally slow central nervous system activity.
What are depressants?
Depressants reduce central nervous system activity and can impair coordination, judgment, and reaction time.
This technique uses electrodes placed on the scalp to record the brain's electrical activity and is frequently used to study sleep stages.
What is an electroencephalogram (EEG)?
EEG records electrical activity with excellent temporal resolution, making it useful for studying sleep, seizures, and rapid neural responses.
Researchers study these siblings, who share nearly 100% of their DNA, to investigate the influence of heredity on behavior.
Who are identical (monozygotic) twins?
Comparing identical and fraternal twins helps researchers estimate genetic contributions to variation in traits.
This fatty insulating layer surrounding many axons speeds up the transmission of neural impulses.
What is the myelin sheath?
Myelin allows action potentials to travel more efficiently through saltatory conduction between nodes of Ranvier.
This process occurs when a sending neuron reabsorbs neurotransmitters from the synaptic gap after they have delivered their message.
What is reuptake?
Reuptake helps terminate neurotransmitter signaling by transporting chemical messengers back into the presynaptic cell.
Cocaine, amphetamines, and caffeine belong to this category of drugs, which generally increase central nervous system activity and alertness.
What are stimulants?
Stimulants increase neural activity and may elevate heart rate, alertness, and energy.
A neurologist wants to identify structural damage following a traumatic brain injury. This technique uses magnetic fields and radio waves to create detailed images of brain anatomy.
What is magnetic resonance imaging (MRI)?
Structural MRI provides detailed images of brain tissue and is useful for identifying anatomical abnormalities.
This statistical estimate describes how much of the variation in a trait within a population is associated with genetic differences.
What is heritability?
Heritability describes variation across a population, not the percentage of an individual's trait caused by genes.
This division of the autonomic nervous system increases heart rate and prepares the body to respond to a perceived threat.
What is the sympathetic nervous system?
The sympathetic division supports fight-or-flight responses; the parasympathetic division supports rest-and-digest functions.
This inhibitory neurotransmitter helps reduce neural activity and is important for regulating anxiety and preventing excessive neuronal firing.
What is GABA?
GABA is the primary inhibitory neurotransmitter in the adult brain. Its action generally makes neurons less likely to fire.
After regularly consuming caffeine, a student must drink three cups of coffee to experience the alertness that one cup previously produced. This illustrates this drug-related phenomenon.
What is tolerance?
Tolerance occurs when repeated exposure to a substance reduces its effects, so a larger dose is needed to produce a similar response.
After a stroke damages part of the brain, rehabilitation helps other neural pathways reorganize to support the recovery of lost abilities. This is an example of this process.
What is neuroplasticity?
Following injury, surviving neural networks may reorganize and compensate for some lost functions, although the degree of recovery varies.
A student inherits a genetic predisposition toward anxiety but develops significant symptoms only after prolonged exposure to stressful circumstances. This illustrates the combined influence of these two factors.
What are genes and environment (gene–environment interaction)?
The effect of a genetic predisposition can depend on environmental conditions; a predisposition does not guarantee an outcome.
When neurotransmitters are released from axon terminals, they cross this tiny gap before binding to receptors on another cell.
What is the synaptic cleft (synaptic gap)?
Neurotransmitters diffuse across the synaptic cleft and bind to receptors on the receiving cell.
Often called the master gland, this endocrine structure releases hormones that regulate several other glands and is controlled by the hypothalamus.
What is the pituitary gland?
The pituitary influences growth, reproduction, and other endocrine glands, while the hypothalamus regulates its activity.
A person who regularly uses nicotine experiences irritability, anxiety, and difficulty concentrating after abruptly stopping. These symptoms illustrate this process.
What is withdrawal?
Withdrawal involves physical or psychological symptoms that occur when someone reduces or stops using a substance after developing dependence.
Researchers ask participants to solve math problems while this scanning technique measures changes in blood oxygenation to identify brain regions associated with the task.
What is functional magnetic resonance imaging (fMRI)?
fMRI measures blood-oxygen-level-dependent signals, providing an indirect indicator of neural activity.