Genetics, Nervous System, and Behavior: Key Concepts for Psychology

Heredity

the passing on of physical or mental characteristics genetically from one generation to another.

Nature

what we think of as pre-wiring and is influenced by genetic inheritance and other biological factors.

Nurture

generally taken as the influence of external factors after conception, e.g., the product of exposure, life experiences and learning on an individual.

Genetic Predisposition

An increased chance or likelihood of developing a particular disease based on the presence of one or more genetic variants and/or a family history suggestive of an increased risk of the disease.

Evolutionary Psychology

the branch of psychology that studies the mental adaptations of humans to a changing environment

Natural Selection

certain behaviors and genes best for survival (Survival of the Fittest)

Identical twins

twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms

Fraternal twins

twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.

Eugenics

the study of how to arrange reproduction within a human population to increase the occurrence of heritable characteristics regarded as desirable

Epigenetics

The study of environmental influences on gene expression that occur without a DNA change

Twin studies

studies conducted on identical or fraternal twins. They aim to reveal the importance of environmental and genetic influences for traits, phenotypes, and disorders.

Adoption studies

compare pairs of persons, e.g., adopted child and adoptive mother or adopted child and biological mother, to assess genetic and environmental influences on behavior.

Family studies

provide a way for professionals to further examine the relationship between genetics and mental disorders.

Behavioral genetics

on discovering how genes and experiences interact and lead to specific behaviors and mental abilities

Genes

segments of DNA that contain instructions to make proteins - building blocks of life

Genome

the entirety of that individual's hereditary information

Mutations

is a permanent change in an organism's genetic material

Nervous System

The body's electrochemical communications network.

Central Nervous System

The brain & spinal cord, which distribute & process messages.

Peripheral Nervous System

A branch of the human nervous system that includes all components except the brain and spinal cord

Somatic Nervous System

The part of the peripheral nervous system that controls voluntary movements

Autonomic Nervous System

A part of the peripheral nervous system that regulates bodily processes such as breathing, heart rate, and digestion

Sympathetic nervous System

branch of the autonomic nervous system that excites body by preparing it for action (increased heartbeat, pupils dilate, lungs increase oxygen, relax bladder, etc) FIGHT OR FLIGHT

Parasympathetic Nervous System

branch of the autonomic nervous system that restore the body's energy sources once they have been depleted (pupils constrict, heart beat slows, constrict airways, stomach contract, etc), REST AND DIGEST

Nerves

are bundles of fibers that transmit impulses between different areas within our bodies

Reflex

is an involuntary response to a stimulus that happens without conscious thought

Neurons

individual nerve cells that make up our entire nervous system

Glial cells

provide nutrition and protection for the neurons

Sensory neurons

neurons that take information from the senses to the brain

Motor neurons

neurons that take information from the brain to the rest of the body

Interneurons

in the brain or spinal cord, neurons that take messages and send them elsewhere in the brain or spinal cord

Spinal Reflex

An immediate response to external stimuli directed at the level of the spinal cord

Mirror Neurons

neurons that play a role in action understanding, imitation learning, and language processing. Enables use to recreate and embody the intentions of others.

Action Potential

An impulse or brief electric charge that travels down the axon.

Threshold

The level of stimulation needed to trigger a neural impulse.

All or None Response

A neuron either sends an impulse or it does not.

Resting Potential

When a neuron does not have an action potential

Polarized

The state of a resting neuron; the outside of the membrane is positively charged while the inside of the membrane is negatively charged.

Depolarization

describes an axon that is firing. Positive ions enter the axon, and cause other positive ions to move into the axon in the form of a neural impulse down the axon.

Refractory Period

A resting pause, where neurons pump positively charged sodium ions back outside of the cell.

Reuptake

The reabsorption of neurotransmitters by the sending neuron.

Excitatory neurotransmitters

send signals that stimulate the brain

Inhibitory neurotransmitters

send signals to calm the brain down and create balance.

Multiple Sclerosis (MS)

The loss of muscle control resulting from a deterioration of myelin sheath

Myasthenia gravis (MG)

is a relatively rare acquired, autoimmune disorder caused by an antibody-mediated blockade of neuromuscular transmission resulting in skeletal muscle weakness and rapid muscle fatigue (caused by a blockage of acetylcholine)

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons that generate the next neural impulse.e3sm, growth and development, tissue function, sexual function, reproduction, sleep, and mood, etc

Hormone

A chemical messenger produced in the body that controls and regulates the activity of certain cells or organs (released in the bloodstream)

Adrenaline

a hormone that activates the sympathetic nervous system. This triggers our "fight or flight" response, which increases heart rate, dilates the pupil, increases blood flow to skeletal muscle, and reduces digestive and reproductive activity

Melatonin

a hormone known to regulate sleep and wake cycles

Ghrelin

increases hunger, secreted by an empty stomach

Leptin

decreases hunger, protein hormone secreted by fat cells

Oxytocin

is a hormone produced by the hypothalamus and released by the pituitary gland that plays a significant role in social bonding, sexual reproduction, childbirth, and the period after childbirth

Psychoactive drugs

chemical substances that alter perceptions, mood, or behavior

Addiction

craving for a chemical substance despite its adverse effects

Tolerance

after long-term use the brain then produces less of that specific neurotransmitter - this creates a need for increasing amounts of the drug to experience the same effect

Withdrawal

set of symptoms associated with discontinuing a drug - reverses neuroadaptation

Substance Abuse Disorder

continued substance craving and use despite significant life disruption and/or physical risk

Depressants

lower neural activity and slow body functioning

Alcohol

slows neural processing and thinking and impairs physical activity

Opiates

drugs that reduce neurotransmission and temporarily lessen pain and anxiety

Barbiturates

A class of depressant drugs. (The study guide lists the term without a definition.)

Stimulants

drugs that speed up the body's functions

Caffeine, Nicotine, Cocaine, meth, Amphetamines

Examples of stimulants.

Hallucinogens (psychedelics)

drugs that distort perceptions of reality

LSD, Marijuana

Examples listed under hallucinogens in the study guide.

Agonists

chemicals that activate the receptors for certain neurotransmitters and make the effects of neurotransmitters stronger

Selective Serotonin Reuptake Inhibitors (SSRIs)

agonists for serotonin. SSRIs increase the amount of serotonin available to the brain, and are commonly prescribed for depression.

Antagonists

chemicals that inhibit the actions of neurotransmitters

Reuptake inhibitors

are drugs that prevent the axon terminals from engaging in the reuptake of neurotransmitters.

Brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; this part is responsible for automatic survival functions

Medulla

controls heartbeat, blood circulation, breathing, muscle maintenance, regulation of reflexes like sneezing/coughing.

Reticular activating system

regulate behavioral arousal, consciousness and motivation (generally control some voluntary movement, eye movement, and some types of learning, cognition, and emotion)

Cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory

Thalamus

the brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

Limbic System

neural system (includes the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives

Hippocampus

vital to our memory system

Amygdala

The amygdala is the center of emotion and is responsible for fear and aggressive responses

Hypothalamus

The hypothalamus regulates the autonomic nervous system (flight or fight), temperature, hunger, and sex.

Pituitary Gland

the "master control gland;" controls other glands and makes the hormones that trigger growth

Hemisphere

the brain has two hemispheres, the left and the right. The left controls the right side of the body and the right controls the left side of the body.

Left Hemisphere

specializes in language, speech, handwriting, calculation, sense of time and rhythm

Right Hemisphere

specializes in processing involving perception, visualization, recognition of faces & emotions

Corpus Callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

Cerebral Cortex

the outer layer of tissue of the hemispheres, and smaller subcortical structure

Frontal Lobe

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements

Prefrontal cortex

located at the very front of the frontal lobe, and it controls executive functions or a set of abilities that are needed to control cognitive behaviors. These behaviors include attention, inhibition, working memory, problem-solving and planning.

Broca's Area

is located in the left hemisphere in the frontal lobe. This area is responsible for speech production and language comprehension. Damage to this area can result in Broca's aphasia.

Parietal Lobe

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

Occipital Lobe

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields, contains the visual cortex

Temporal Lobe

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas and helps with hearing and meaningful speech, contains the primary auditory cortex

Wernicke's area

is located in the back of the temporal lobe near the occipital lobe of the left cerebral hemisphere and is involved in understanding written and spoken language. Damage to this area is called Wernicke's Aphasia.

Motor Cortex

an area at the rear of the frontal lobes that controls voluntary movements

Sensory Cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Association Areas

areas in the cerebral cortex involved in higher mental function.

Contralateral Hemispheric Organization

the arrangement whereby the motor cortex of each cerebral hemisphere is mainly responsible for control of movements of the contralateral (opposite) side of the body.

Split Brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

Neuroplasticity

reorganization of neural pathways as a result of experience

Brain Lesion

Lesions are tissue that is destroyed (disease, Traumatic Brain Injuries, drug abuse, etc).

EEG

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

fMRI

a technique for revealing blood flow, and, therefore, brain activity by comparing successive MRI scans. These scans show brain function as well as its structure