Edit · Psychology Unit 3: Brain and Biology

neuron

a nerve cell; the basic bulding block of the

dendrite

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

axon

A threadlike extension of a neuron that carries nerve impulses away from the cell body.

terminal branches

the endpoints of a neuron where neurotransmitters are stored

action potential

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

resting potential

the state of the neuron when it is at rest, but capable of generating an action potential

synapse

tiny, fluid filled gap between the terminal branches of one neuron and the dendrites of another

neurotransmitter

chemical messenger used by a neuron to transmit an impulse across a synapse to another cell; influences whether a neuron will generate an action potential

serotonin

A neurotransmitter that affects hunger,sleep, arousal, and mood.

dopamine

a neurotransmitter that regulates motivation, pleasure, and emotional arousal

receptor cells

Specialized cells in every sensory system of the body that can turn other kinds of energy into action potentials (neural impulses) that the brain can process.

transduction

the process of changing sensory energy into nerve impulses that the brain can detect and interpret

sensory nerves

nerves that carry information form the sense receptors to the spinal cord and brain

central nervous system (CNS)

the brain and the spinal cord

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

somatic nervous system

division of the PNS that controls the body's skeletal muscles

autonomic nervous system

division of the PNS that controls glands and muscles of the internal organs; includes the sympathetic and parasympathetic nervous divisions

sympathetic nervous system

part of the autonomic nervous system that arouses the body to deal with perceived threats

parasympathetic nervous system

part of the autonomic nervous system that calms the body

endocrine system

a set of glands that produce hormones

hormone

chemical messenger produced by the endocrine glads and circulated in the blood

pituitary gland

the master gland of the endocrine system; connected to the hypothalamus and controls the other endocrine glands

brainstem

the central core of the brain; begins where the spinal cord swells as it enters the skull and is responsible for automatic survival functions

medulla

located at the base of the brainstem; controls basic life-support functions like heartbeat and breathing

thalamus

the brain's sensory switchboard located on top of the brainstem; directs messages to the sensory receiving areas in the cortex

cerebellum

the "little brain" attached to the rear of the brainstem which helps coordinate voluntary movements and balance

limbic system

a group of structures at the border of the brainstem and cerebral cortex which help regulate memory, fear, aggression, hunger and thirst; includes the hypothalamus, hippocampus, and amygdala

hypothalamus

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

hippocampus

A neural center located in the limbic system that helps process new memories for permanent storage

amygdala

an almond-shaped neural cluster in the limbic system that controls emotional responses, such as fear and anger

cerebral cortex (cerebrum)

the intricate fabric of interconnected neurons that form the body's ultimate control and information processing center

longitudinal fissure

the long crevice that divides the cerebral cortex into the left and right hemispheres

corpus callosum

the large band of neural tissue that connects the two brain hemispheres and allows them to communicate with each other

frontal lobes

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

parietal lobes

portion of the cerebral cortex lying at the top of the head and toward the rear; includes general association areas used for processing information like math reasoning and integration of memory; includes the somatosensory cortex

occipital lobes

portion of the cerebral cortex lying at the back of the head; includes the primary visual processing areas of the brain

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

a strip of brain tissue at the rear of the frontal lobes that controls voluntary movements

somatosensory cortex

a strip of brain tissue at the front of the parietal lobes that register and processes body sensations

neuroplasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or experience

Broca's area

a brain area of the left frontal lobe that directs the muscle movements involved in speech

Wernicke's area

a brain area of the left temporal lobe involved in language comprehension (receptive language) and expression

sensation

the process by which sensory systems and the nervous system receive stimuli from the environment

perception

the process of organizing and interpreting incoming sensory information

absolute threshold

the minimum amount of stimulation needed to detect a particular stimulus

difference threshold

the minimum amount of difference needed to detect that two stimuli are not the same

sensory adaptation

diminished sensitivity to constant and unchanging stimulation

selective attention

focusing conscious awareness on a particular stimulus to the exclusion of others

Trichromatic Theory of Color Vision

theory which says that cones are sensitive to red, green, or blue light - the three colors that combine to create millions of color combinations

Opponent-Process Theory

theory which says color is processed by cones organized in opponent pairs; light stimulates one half of the pair and inhibits the other half

sound localization

the process by which the location of sound is determined

sensory interdependence

our senses, to some extent, work together and are not exclusively independent

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle; hypothalamus helps manage the cycle

melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

stress

the process by which we perceive and respond to threats

General Adaptation Syndrome (GAS)

the theory that the body's adaptive response to stress is a three-phase process of alarm, resistance, and exhaustion

REM sleep

a stage of sleep characterized by rapid eye movements and a high level of brain activity including dreaming; somatosensory cortex is "turned off"

cortisol

stress hormone which increases the length of the resistance stage of the GAS model and can affect sleep and memory

daily stress

little stressors that actually accumulate to be the most significant because of frequency; lead to burnout