Psychology in Everyday Life Chapter 2

biological psychology

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

dendrites

Neuron extensions that receive messages and conduct them toward the cell body.

axon

Neuron extension that sends messages to other neurons or cells.

neuron

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

action potential

A nerve impulse.

synapse

Junction between the axon tip of a sending neuron and the dendrite or cell body of a receiving neuron.

threshold

Level of stimulation required to trigger a neural impulse.

all-or-none response

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

neurotransmitters

Neuron-produced chemicals that cross synapses to carry messages to other neurons or cells.

opiate

Chemical, such as opium, morphine, and heroin, that depresses neural activity, temporarily lessening pain and anxiety.

endorphins

"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 central and peripheral nervous systems.

central nervous system (CNS)

The brain and spinal cord.

peripheral nervous system (PNS)

The sensory and motor neurons connecting 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.

sensory neuron

Neuron that carries incoming information from the sensory receptors to the central nervous system.

motor neuron

Neuron that carries outgoing information from the central nervous system to the muscles and glands.

interneuron

Neuron that processes information between sensory input and motor outputs.

somatic nervous system

Peripheral nervous system division controlling the body's skeletal muscles. Also called the skeletal nervous system.

autonomic nervous system

Peripheral nervous system division controlling the glands and the muscles of the internal organs. Its sympathetic subdivision arouses; its parasympathetic subdivision calms.

sympathetic nervous system

Autonomic nervous system subdivision that arouses the body, mobilizing its energy in stressful situations.

parasympathetic nervous system

Autonomic nervous system subdivision that calms the body, conserving its energy.

endocrine system

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

hormones

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

adrenal glands

Pair of endocrine glands that sit just above the kidneys and secret hormones (epinephrine and norephinephrine) that help arouse the body in times of stress.

pituitary gland

Most influential endocrine gland. Under the influence of the hypothalamus, it regulates growth and controls other endocrine glands.

brainstem

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

medulla

The base of the brainstem; controls heartbeat and breathing.

thalamus

Area at the top of the brainstem; directs sensory messages to the cortex and transmits replies to the cerebellum and medulla.

reticular formation

Nerve network running through the brainstem and thalamus; plays an important role in controlling arousal.

cerebellum

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

hypothalamus

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

cerebral cortex

Thin layer of interconnected neurons covering the cerebral hemispheres; the body's ultimate control and information-processing center.

frontal lobes

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

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 receives information from the visual fields.

temporal lobes

Portion of the cerebral cortex lying roughly above the ears; includes areas that receives information from the ears.

motor cortex

Cerebral cortex area at the rear of the frontal loves; controls voluntary movements.

sensory cortex

Cerebral cortex area at the front of the parietal lobes; registers and processes body touch and movement sensations.

hallucination

False sensory experience, such as hearing something in the absence of an external auditory stimulus.

association areas

Cerebral cortex area involved primarily in higher mental functions, such as learning, remembering, thinking, and speaking.

Broca's area

Frontal lobe area, usually in the left hemisphere, that directs the muscle movements involved in speech; controls language expression.

Wernicke's area

Brain area, usually in the left temporal lobe, involved in language comprehension and expression; controls language reception.

plasticity

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

neurogenesis

Formation of new neurons.

corpus callosum

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

split brain

Condition in which the brain's two hemispheres are isolated by cutting the fibers (mainly those of the corpus callosum) connecting them.

consciousness

Our awareness of ourselves and our environment.

selective attention

Focusing conscious awareness on a particular stimulus.

inattentional blindness

Failure to see visible objects when our attention is directed elsewhere.

circadian rhythm

Internal biological clock; regular bodily rhythms that occur on a 24-hour cycle.

REM (rapid eye movement) sleep

Recurring stage of sleep during which vivid dreams commonly occur. Also known as paradoxical sleep because the muscles are relaxed (except for minor twitches) but other body systems are active.

alpha waves

Relatively slow brain waves of a relaxed, awake state.

sleep

Periodic, natural, reversible loss of consciousness- as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

insomnia

Recurring problem in falling or staying asleep.

narcolepsy

Sleep disorder in which a person has uncontrollable sleep attacks, sometimes lapsing directly into REM sleep.

sleep apnea

A sleep disorder in which a sleeping person repeatedly stops breathing until blood oxygen is so low it awakens the person just long enough to draw a breath.

dream

Sequence of images, emotions, and thought passing through a sleeping person's mind.

manifest content

According to Freud, the remembered story line of a dream.

latent content

According to Freud, the underlying meaning of a dream.

REM rebound

the tendency for REM sleep to increase following REM sleep deprivation