Psychology, Chapter 2 Biology and Behavior Vocabulary

neurons

specialized cells of the nervous system that transmit electrical and chemical signals in the body

neuroscience

the study of the brain and other parts of the nervous system

biological psychology

the branch of psychology that focuses on how the brain and other biological systems influence human behavior

phrenology

an early approach to explaining the functions of the brain by trying to link the physical structure of the skull with a variety of characteristics

cell body

the region of the neuron that includes structures that nourish the cell, and a nucleus containing DNA

dendrites

tiny, branchlike fibers extending from the cell body that receive messages from other neurons and send information in the direction of the cell body

axon

skinny tube like structure of a neuron that extends from the cell body and sends messages to other neurons and sends information in the direction of the cell body. (not all axons are myelinated)

myelin sheath

a fatty substance that insulates the axon and speeds the transmission of neural messages.

synapse

the place where the axon terminal of a sending neuron meets the dendrite of a neighboring neuron or other type of cell receiving its signal; junction between neurons where communication occurs

glial cells

cells of the nervous system that support, nourish, and protect neurons

resting potential

the electrical potential of a cell "at rest"; the state of a cell when it is not activated

action potential

the spike in voltage that passes through the axon of a neuron, the result of which is to convey information

all-or-none

a neuron either fires or does not fire; action potentials are always the same strength

neurotransmitters

chemical messengers that neurons use to communicate at the synapse

receptor sites

locations on the receiving neuron's dendrites where neurotransmitters attach.

reuptake

a process by which neurotransmitters are reabsorbed by the sending axon terminal

sensory neurons

neurons that receive information from the sensory systems and convey it to the brain for further processing

motor neurons

neurons that transmit information from the central nervous system to the muscles and glands

interneurons

neurons that reside exclusively in the brain and spinal cord; act as a bridge connecting sensory and motor neurons

reflex arc

an automatic response to a sensory stimulus, using a simple pathway of communication from sensory neurons through interneurons in the spinal cord and back out through motor neurons

nerves

bundles of neurons that carry information to and from the central nervous system; enable communication between the central nervous system and the muscles, glands, and sensory receptors.

somatic nervous system

the branch of the peripheral nervous system that includes sensory nerves and motor nerves; gathers information from sensory receptors and controls the skeletal muscles responsible for voluntary movement.

autonomic nervous system

the brance of the peripheral nervous system that controls involuntary processes within the body, such as contractions in the digestive tract and activity of glands.

sympathetic nervous system

the division of the autonomic nervous system that mobilizes the "fight-or-flight" response to stressful or crisis situations.

parasympathetic nervous system

the division of the autonomic nervous system that orchestrates the "rest-and-digest" response to bring the body back to a noncrisis mode.

endocrine system

the communication system that uses glands to convey messages by releasing horomones into the bloodstream.

horomones

chemical messengers released into the bloodstream that influence mood, cognition, appetite, and many other processes and behaviors.

pituitary gland

the small endocrine gland located in the center of the brain just under the hypothalamus; known as the master gland.

thyroid gland

the endocrine gland that regulates the rate of metabolism by secreting thyroxin

adrenal glands

endocrine glands involved in response to stress and the regulation of salt balance.

cerebrum

the largest area of the brain, includes virtually all parts of the brain except the brain stem structures; has two distinct hemispheres

corpus callosum

the thick band of nerve fibers connecting to the right and left cerebral hemispheres; principal structure for information sharing between the two hemispheres

split brain operation

a rare procedure used to disconnect the right and left hemispheres; involves cutting the corpus callosum

lateralization

the idea that each cerebral hemisphere processes certain types of information and excels in certain activities

broca's area

a region of the cortex that is critical for speech production

wernicke's area

a region of the cortex that plays a pivotal role in language comprehension.

neurogenesis

the generation of new neurons in the brain

stem cells

cells responsible for producing new neurons

cerebral cortex

the wrinkled outermost layer of the cerebrum, responsible for higher mental functions, such as decision making, language, and processing visual information.

frontal lobes

the area of the cortex that directs higher-level cognitive activities, such as language, emotions, control of social behavior, and decision making.

parietal lobes

the area of the cortex that receives and processes sensory information such as touch, pressure, temperature, and spatial orientation.

occipital lobes

the area of the cortex in the back of the head that processes visual information

temporal lobes

the area of the cortex that processed auditory stimuli and language

motor cortex

a strip of brain tissue toward the rear of the frontal lobes that works with other brain regions to plan an execute voluntary movements

association areas

regions of the cortex that integrate information from all over the brain, allowing us to learn, think in abstract terms, and carry out complex behaviors.

limbic system

a collection of structures that regulates emotions and basic drives such as hunger, and aids in the creation of memories

thalamus

a structure in the limbic system that processes and relays sensory information to the appropriate areas of the cortex

hypothalamus

a small structure located below the thalamus that maintains the internal environment within a healthy range; helps regulate sleep-wake cycles, sexual behavior, and appetite

amygdala

a pair of almond-shaped structures in the limbic system that processes aggression and basic emotion such as fear, as well as associated memories.

hippocampus

a pair of sea-horse shaped structures located in the limbic system; primarily responsible for creating new memories.

forebrain

the largest part of the brain; includes the cerebrum and the limbic system.

midbrain

the part of the brainstem involved in levels of arousal; responsible for generating movement patterns in response to sensory input.

reticular formation

a network of neurons running through the midbrain that controls levels of arousal and quickly analyzes sensory information on its way to the cortex.

hindbrain

includes areas of the brain responsible for fundamental life-sustaining processes

pons

a hindbrain structure that helps regulate sleep-wake cycles and coordinate movement between the right and left sides of the body

medulla

a hindbrain structure that oversees vital functions, including breathing, digestion, and heart rate.

cerebellum

a hindbrain structure located behind the brainstem that is responsible for muscle coordination and balance; Latin for "little brain"

Terminal buttons (axon terminals)

Transmit signal to the next neuron

Node of Ranvier

A gap in the myelin sheath

Acetylcholine (ACh)

Relays messages from neurons to muscles, enabling
movement (botulism [e.g., Botox] inhibits release of ACh)
Too much = spasms; too little = paralysis
Low levels in the brain linked to Alzheimer’s disease

Glutamate

Excitatory neurotransmitter (e.g., MSG)
Plays a central role in learning and memory
Too much = strokes; too little = symptoms of
schizophrenia

GABA (gamma-aminobutyric acid)

Inhibitory neurotransmitter
Plays role in controlling sleep, wakefulness, and
intoxication

Epinephrine (adrenaline)

energy

Norepinephrine

Prepares the body for stress.
In the brain, norepinephrine is involved in regulating
arousal and sleep.
High levels could lead to overarousal and hypervigilance.

Endorphins

A group of naturally produced opioids
Released in response to pain and block pain receptor
sites
Also released with brisk exercise (e.g., “runner’s high”)

Serotonin

Helps control appetite, aggression, and mood, and
regulates sleep and breathing.
Abnormally low activity is thought to drive depression.
SSRIs help boost the effects of serotonin.

Dopamine

Emotional arousal (fear, anxiety), motivation/reward
(hunger, thirst, sex), pleasure, drug abuse (e.g., cocaine
and amphetamines)
Plays a key role in attention, learning through
reinforcement, and regulating body movements
Parkinson’s disease is linked to a deterioration of
neurons that produce dopamine.