AP Psych Unit 1 - Biological Bases of Behavior

Heredity (Nature)

The genetic transfer of characteristics from parents to offspring.

Environment (Nurture)

Nongenetic influences, from prenatal nutrition to ones experiences of the people and things around oneself.

Dizygotic/Fraternal Twins

Individuals who developed from separate fertilized egg. Shared a prenatal environment but are genetically no closer than normal siblings.

Monozygotic/Identical Twins

Individuals who developed from a single fertilized egg that split in two, creating two genetically identical organisms.

Evolutionary Psychology

The study of the evolution of behavior and the mind, using principles of natural selection.

Behavioral Genetics

The study of the relative power and limits of genetic and environmental influences on behavior.

Natural Selection

The principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.

Epigenetics

The study of the molecular mechanisms by which environments can influence gene expression (without a DNA change).

Eugenics

Discriminatory 19th and 20th century movement that proposed measuring human traits and encouraging only those deemed ‘fit’ to reproduce.

Heritability

A measure of how well differences in people’s genes account for differences in their traits.

Endocrine System

The body’s ‘slow’ chemical communication system; a set of glands and fat tissue that secrete hormones into the bloodstream.

Hormones

Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

Pituitary Gland

A pea-sized structure located in the core of the brains, controlled by the hypothalamus.
-
Also

Adrenaline

Also known as epinephrine, increases heart rate, blood pressure, and blood sugar, providing a surge of energy to power the fight-or-flight response.

Leptin

Hunger-supressing hormone, partner to ghrelin

Ghrelin

Hunger-arousing hormone, partner to leptin

Melatonin

Sleep-inducing hormone found in the hypothalamus

Oxytocin

Enables orgasm, labor contractions and milk flow when nursing.

Central Nervous System

Brain & Spinal Cord

Peripheral Nervous System

The sensory and motor neurons that connect the CNS to the rest of the body.

Somatic Nervous System

Division of the peripheral nervous system that controls the body’s skeletal muscles.

Autonomic Nervous System

Part of the peripheral nervous system that controls the glands and the muscles of internal organs.

Its sympathetic division arouses; its parasympathetic division calms

Sympathetic Nervous System

Division of the autonomic nervous system that arouses the body, mobilizing its energy.

Parasympathetic Nervous System

Division of the autonomic nervous system that calms the body, conserving its energy.

Neurons

Nerve cells that form a communication network throughout the body.

Sensory Neurons

Neurons that carry incoming information from the body’s tissues and 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; they communicate internally and process information between the sensory inputs and motor inputs.

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons; may also play a role in learning, thinking, and memory.

Dendrites

A neuron’s branching extensions that receive and integrate messages, conducting impulses toward the cell body.

Soma (Cell Body)

Part of a neuron that contains the nucleus; the cell’s life-support center.

Axon

Segmented 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; it enables vastly greater transmission speed as neural impulses hop from one node to the next.

Terminal Branches/Buttons

Form junctions with other cells/neurons.

Receptor Sites

Spaces on the neural cells that can receive chemical signals from neurotransmitters.

Synapses/Synaptic Gap

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.

All-or-Nothing Principle/Response

A neuron’s reaction of either firing (with a full strength response) or not firing.

Resting Potential

The imbalance of electrical charge that exists between the interior of a neuron and the exterior environment.

Depolarization

The loss of the inside/outside charge difference.

Threshold

The level of stimulation required to trigger a neural impulse.

Action Potential

A neural impulse; a brief electrical charge that travels down an axon.

Refractory Period

A brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.

Reuptake

A neurotransmitter’s re-absorption by the sending neuron.

Agonist/Reuptake Inhibitor

A molecule that increases a neurotransmitter’s action.

Antagonist

A molecule that inhibits/blocks a neurotransmitter’s action.

Spinal Reflexes/Reflex Arc

Automatic and stereotyped response to a specific sensory stimulus that involves the spinal cord.

Long-Term Potentiation (LTP)

A persistent increase in the efficacy of synaptic transmission in certain brain cells. Associated with the strengthening of neural connections.

Excitatory Neurotransmitters

Inhibitory Neurotransmitters

Acetylchloline

Enables muscle action, learning, and memory.

Norepinephrine

Helps control alertness and arousal.

Glutamate

A major excitatory neurotransmitter; involved in memory.

Dopamine

Influences movement, learning, attention, and emotion.

Serotonin

Affects mood, hunger, sleep, and arousal.

GABA (Gamma-aminobutyric acid)

A major inhibitory neurotransmitter.

Substance P

Involved in pain perception and immune response

Endorphins

Neurotransmitters that influence the perception of pain or pleasure.

Multiple Sclerosis

Issues with the myelin sheath, communication problems between nerves.

Myasthenia Gravis

Antibodies block/destroy binding of neurotransmitters with muscle cells at the muscle cells.

Depressants

Drugs that calm neural activity and slow body functions.

Alcohol

A depressant, acts as a dis-inhibitor, slowing brain activity that controls judgements and inhibitions.

Stimulants

Drugs that excite neural activity and speed up body functions.

Caffeine

A Stimulant, increased alertness and wakefulness, and can result in anxiety, restlessness, and insomnia in high doses.

Cocaine

Powerfully addictive stimulant derived from the coca plant. Enters the bloodstream quickly and produces a rush of euphoria that depletes the brain’s supply of dopamine, serotonin, and norepinephrine.

Hallucinogens

Psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input.

Marijuana

A hallucinogen that amplifies sensitivity to colors, sounds, tastes, and smells. It also relaxes, dis-inhibits, and may produce a euphoric high.

Opioids

Opium and its derivatives; depresses neural activity, temporarily lessening pain and anxiety.

Heroin

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

Everyday terms for compulsive substance use that continue despite harmful consequences.

Physical Dependence

Unpleasant physical symptoms occur if a drug is suddenly stopped or taken in smaller doses. Individual has a chemical need for said drug.

Psychological Dependence

Emotional or mental attachment to a substance or behavior.

Withdrawal

The discomfort and distress that follow after discontinuing an addictive drug or behavior.

Brainstem

The central core of the brain, beginning where the spinal cord swells as it enters the skull; responsible for automatic survival functions.

Medulla

The hindbrain structure that is the brainstem’s base; controls the heartbeat and breathing.

Pons

Cerebellum

The hindbrain’s ‘little brain’ at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.

Reticular Activating System/Reticular Formation

A nerve network that travels through the brainstem into the thalamus; filters information and plays an important role in controlling arousal.

Reward Center

Hippocampus

A neural center in the limbic system that helps process explicit (conscious) memories - of facts and events - for storage.

Ventral Tegmental Area

Regulates reward consumption. learning, memory, and addiction behaviors through mediating dopamine release in other regions of the brain.

Nucleus Accumbens

Component of the ventral striatum, known for roles in pleasure, reward, and addiction.

Pre-Frontal Cortex

Found in the forward part of the frontal lobes; enables judgement, planning, social interactions, and processing of new memories.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the forebrain’s cerebral hemispheres; the body’s ultimate control and information processing center.

Limbic System

Neural system located mostly in the forebrain below the cerebral hemispheres, contains the amygdala, hypothalamus, hippocampus, thalamus, and pituitary gland.
Associated with emotions and drives.

Thalamus

The forebrain’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.

Hypothalamus

A limbic system neural structure lying below the thalamus; directs several maintenance activities, helps govern the endocrine system, and is linked to emotion and reward.

Hippocampus

Amygdala

Two lima-bean-sized neural clusters in the limbic system; linked to emotion.

Corpus Callosum

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

Frontal Lobes

Portion of the cerebral cortex lying just below the forehead. Enables linguistic processing, muscle movements, higher-order thinking, and executive functioning.

Pre-Frontal Cortex

Motor Cortex

An area of the cerebral cortex at the rear of the frontal lobes that controls voluntary movements.

Parietal Lobes

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

Association Areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions, but rather are involved in high mental functions such as learning, remembering, thinking, and speaking.

Somatosensory Cortex

A cerebral cortex area at the front of the parietal lobes that registers and processes body touch and movement sensations.

Occipital Lobe

Portion of the cerebral cortex lying at the back of the head; includes areas that receive visual information from the visual fields.

Temporal Lobes

Portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each of which receives information primarily from the opposite ear. Also enables language processing.

Contralaterality

Brain Lateralization