AP Psychology Unit 2 - The Biological Basis of Behavior

Biological Psychology

Biological Psychology

A branch of psychology concerned between the links between biology and behavior.

Neuron

A nerve cell; the basic building block of the nervous system.

Sensory Neurons

Neurons that carry incoming information from the 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.

Dendrite

Bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Axon

The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles and glands.

Myelin Sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

Action Potential

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

Resting Potential

Positive-outside/negative-inside state

Threshold

The level of stimulation required to trigger a neural impulse.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

Endorphin

"Morphine within" - natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Nervous System

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System

The brain and spinal cord.

Peripheral Nervous System

The sensory and motor neurons that connect the central nervous system to the rest of the body.

Nerves

Bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs.

Somatic Nervous System

The division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system.

Autonomic Nervous System

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

Parasympathetic Nervous System

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

Endocrine System

The body's "slow" chemical communication system; a set of glands that secret hormones into the bloodstream.

Hormones

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

Adrenal Glands

A pair of endocrine gland that sit just above the kidneys and secret hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

Pituitary Gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, it regulates growth and controls other endocrine glands.

Lesion

Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

Brainstem

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

Medulla

The base of the brainstem; controls heartbeat and breathing.

Reticular Formation

A nerve network in the brainstem that plays an important role in controlling arousal.

Thalamus

The brain's sensory switchboard, 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.

Cerebellum

The "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance.

Limbic System

Neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

Amygdala

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

Hypothalamus

A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Hippocampus

A neural center that is located in the limbic system and helps process explicit memories for storage.

Cerebral Cortex

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

Glial Cells (Glia)

Cells in the nervous system that support, nourish, and protect neurons.

Frontal Lobes

Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

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.

Occipital Lobes

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

Temporal Lobes

Portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.

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

Plasticity

The brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

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.

Neurogenesis

The formation of new neurons.

Corpus Callosum

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

Visual Cortex

Receives written words as visual stimulation.

Angular Gyrus

Transforms visual representations into auditory code.

Wernicke's Area

Interprets auditory code. Allows us to understand language.

Broca's Area

Controls speech muscles via motor cortex. Allows us to speak.

Environment

Every nongenetic influence, from prenatal nutrition to the people and things around us.

Culture

The enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next.

Testosterone

The most important of the male sex hormones. Both males and females have it, but the additional testosterone in males stimulates the growth of the male sex organs in the fetus and the development of male sex characteristics during puberty.

How do neurons relay information to each other? Both in the cell and between

Conduct electrochemical signals to each other

(electrically across the cell, chemically

between the cells).

The largest part of the brain?

Cerebrum

What are the four brain lobes?

Frontal, Temporal, parietal, and occipital.

Refractory Period

A period of inactivity after a neuron has fired

Ions

Electrically charged atoms

Selectively Permeable

The axon's surface is very selective about what it allows through

Depolarize

When positively charged sodium ions flood through the cell membrane, causing another axon channel to open

Excitatory Signal

Depolarizes the cell membrane, increasing the likelihood that the neuron will fire

Inhibitory Signal

Hyperpolarize the cell, decreasing the likelihood that the neuron will fire

All-or-none Response

A neuron's reaction of either firing or not firing

Reuptake

A neurotransmitter's reabsorption by the sending neuron

Acetylcholine

The messenger at every junction between motor neurons

Agonist

A molecule that stimulates a response by binding to a receptor site

Antagonist

A molecule that inhibits or blocks a response by binding to a receptor site

Sensory (afferent) Neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord

Motor (efferent) 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 that communicate internally and intervene between the sensory inputs and motor outputs

Pancreas

Regulates the level of sugar in the blood

Parathyroids

Helps regulate the level of calcium in the blood

Thyroid Gland

Affects metabolism

Electroencephalogram (EEG)

An amplified recording of the waves of electrical activity sweeping across the brain's surface; measured by electrodes placed on the scalp

CT (computed tomography) scan

A series of X-ray photographs taken from different angles and combined by a computer into a composite representation of a slice of the brain's structure

PET (positron emission tomography) scan

A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging)

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue; shows brain anatomy

fMRI (functional MRI)

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans; show brain function as well as its structure

Pons

Help coordinate movement

Spinal Cord

Pathway for neural fibers traveling to and from brain; controls simple reflexes

Dopamine

Mood stabilizer

Influences movement, learning, attention, and emotion

Norepinephrine

Alertness/mood

Serotonin

Mood stabilizer

Affects mood, hunger, sleep, and arousal

GABA

A major inhibitory neurotransmitter

Glutamate

A major excitatory neurotransmitter; involved in memory

Somatosensory Cortex

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

Cognitive Neuroscience

The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)

Dual Processing

The principle that information is often simultaneously processed on separate conscious and unconscious tasks

Behavior Genetics

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

Chromosomes

Threadlike structures made of DNA molecules that contain the genes

DNA

A complex molecule containing the genetic information that makes up the chromosomes

Genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesiszing proteins

Genome

The complete instructions for making an organism, consisting of all the genetic mateial in that organism's chromosomes

Identical Twins (monozygotic twins)

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

Fraternal Twins (dizygotic twins)

Twins who develop from separate fertilized eggs, genetically no closer than brothers and sisters but share a fetal environment

Molecular Genetics

The subfield of biology that studies the molecular structure and function of genes

Heritability

The proportion of variation among individuals that we can attribute to genes; heritability of a trait may vary, depending on the range of populations and environments studied

Interaction

The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)