Chapter 3 - Keywords

neurons

cells in the nervous system that communicate with each other to perform information-processing tasks

cell body (soma)

the largest component of the neuron that coordinates the information-processing tasks and keeps the cell alive

dendrites

receive information from other neurons and relay it to the cell body

axon

carriers information to other neurons, muscles, or glands

myelin sheath

an insulating layer of fatty material

glial cells

support cells found in the nervous system

synapse

the junction or region between the axon of one neuron and the dendrites or cell body of another

sensory neurons

receive information from the external world and convey this information to the brain via the spinal cord

motor neurons

carry signals from the spinal cord to the muscles to produce movement

interneurons

connect sensory nuerons, motor neurons, or other interneurons

resting potential

the difference in electric charge between the inside and outside of a neuron’s cell membrane

action potential

an electric signal that is conducted along the length of a neuron’s axon to a synapse

refractory period

the time following an action potential during which a new action potential cannot be initiated

terminal buttons

knoblike structures that branch out from an axon

neurotransmitters

chemicals that transmit information across the synapse to a receiving neuron’s dendrites

receptors

parts of the cell membrane that receive the neurotransmitter and either initiate or prevent a new electric signal

acetylcholine (ACh)

a neurotransmitter involved in a number of functions, including voluntary motor control

dopamine

a neurotransmitter that regulates motor behavior, motivation, pleasure, and emotional arousal

glutamate

the major excitatory neurotransmitter in the brain

GABA (gamma-amino butyric acid)

the primary inhibitory neurotransmitter in the brain

norepinephrine

involved in states of vigilance, or heightened awareness of dangers in the environment

serotonin

involved in the regulation of sleep and wakefulness, eating, and aggressive behavior

endorphins

chemicals that act within the pain pathways and emotion centers of the brain

agonists

drugs that increase the action of a neurotransmitter

antagonists

drugs that diminish the function of a neurotransmitter

nervous system

an interacting network of neurons that conveys electrochemical information throughout the body

central nervous system (CNS)

composed of the brain and the spinal cord

peripheral nervous system (PNS)

connects the central nervous system to the body’s organs and muscles

somatic nervous system

a set of nerves that conveys information between skeletal muscles and the central nervous system

autonomic nervous (ANS)

a set of nerves that carries involuntary and automatic commands that control blood vessels, body organs, and glands

sympathetic nervous system

a set of nerves that prepares the body for action in challenging or threatening situations

parasympathetic nervous system

helps the body return to a normal resting state

spinal reflexes

simple pathways in the nervous system that rapidly generate muscle contractions

reflex arc

a neural pathway that controls reflex actions

hindbrain

an area of the brain that coordinates information coming into and out of the spinal cord

medulla

an extension of the spinal cord into the skull that coordinates heart rate, circulation, and respiration

reticular formation

regulates sleep, wakefulness, and levels of arousal

cerebellum

a large structure of the hindbrain that controls fine motor skills

pons

a structure that relays information from the cerebellum to the rest of the brain

tectum

orients an organism in the environment

tegmentum

involved in movement and arousal

cerebral cortex

the outermost layer of the brain, visible to the naked eye, and divided into two hemispheres

subcortical structures

areas of the forebrain housed under the cerebral cortex near the center of the brain

thalamus

relays and filters information from the sense and transmits the information to the cerebral cortex

hypothalamus

regulates body temperature, hunger, thirst, and sexual behavior

hippocampus

critical for creating new memories and integrating them into a network of knowledge so that they can be stored indefinitely in other parts of the cerebral cortex

amygdala

located at the tip of each horn of the hippocampus, plays a central role in many emotional processes, particularly the formation of emotional memories

basal ganglia

a set of subcortical structures that directs intentional movements and plays a role in reward processing

endocrine system

a network of glands that produce and secrete into the bloodstream chemical messages known as hormones, which influence a wide variety of basic functions, including metabolism, growth, and sexual development

pituitary gland

the “master gland” of the body’s hormone-producing system, which releases hormones that direct the functions of many other glands in the body

corpus callosum

connects large areas of the cerebral cortex on each side of the brain and supports communication of information across the hemispheres

occipital lobe

processes visual information

parietal lobe

processing information about touch

temporal lobe

responsible for hearing and language

frontal lobe

specialized areas for movement, abstract thinking, planning, memory, and judgment

association areas

composed of neurons that help provide sense and meaning to information registered in the cortex

mirror neurons

active when an animal performs a behavior, such as reaching for or manipulating an object, and are also activated when another animal observes that animal performing the same behavior

cultural neuroscience

the study of how culture and neurobiological processes influence one another

gene

the major unit of hereditary transmission

chromosomes

strands of DNA wound around each other in a double-helix configuration

epigentics

the study of environmental influences that determine whether or not genes are expressed, or the degree to which they are expressed, without altering the basic DNA sequences that constitute the genes themselves

epigenetic marks

chemical modifications to DNA that can turn genes on or off

DNA methylation

adding a methyl froup to DNA

histone modification

adding chemical modifications to proteins called histones that are involved in packaging DNA

heritability

a measure of the variability of behavioral traits among individuals that can be accounted for by genetic factors

electroencephalograph (EEG)

a device used to record electrical activity in the brain