Chapter 2: Psychology in your life 4th edition

nervous system

A network of billions of cells in the brain and the body, responsible for all aspects of what you think, feel, and do.

central nervous system (CNS)

The part of the nervous system that consists of the nerve cells in the brain and the spinal cord.

peripheral nervous system (PNS)

The part of the nervous system that consists of all the nerve cells throughout the body except those in the brain and spinal cord.

neurons

The nerve cells that are the basic units of the nervous system; these cells receive, integrate, and transmit information in the nervous system. Neurons operate through electrical impulses, communicate with other neurons through chemical signals, and form neural networks.

dendrites

Branchlike extensions of the neuron's cell body with receptors that receive information from other neurons.

cell body

Part of the neuron where information from thousands of other neurons is collected and integrated.

axon

A long, narrow outgrowth of a neuron's cell body that lets the neuron transmit information to other neurons.

terminal buttons

Parts of the neuron at the end of axons that release chemical signals from the neuron into the synapse.

synapse

The gap between the terminal buttons of a sending neuron and the dendrites of a receiving neuron.

neurotransmitters

Chemicals that carry signals from one neuron to another.

action potential

The neural impulse that travels along the axon and then causes the release of neurotransmitters into the synapse.

myelin sheath

A fatty material that covers and insulates some axons to allow for faster movement of electrical impulses along the axon.

Broca's area

A small portion of the left frontal region of the brain; this area is crucial for producing speech.

medulla

A hindbrain structure at the top of the spinal cord; it controls survival functions such as
heart rate and breathing.

pons

A hindbrain structure above the medulla; it regulates sleep and arousal and coordinates movements of the left and right sides of the body.

cerebellum

A hindbrain structure behind the medulla and pons; it is essential for motor learning, coordination, and balance.

thalamus

A subcortical forebrain structure; the gateway to the brain for sight, sound, touch, and taste sensory information before that information reaches the cortex.

hypothalamus

A subcortical forebrain structure involved in regulating bodily functions. The hypothalamus also influences basic motivated behaviors.

hippocampus

A subcortical forebrain structure; it is associated with the formation of new memories and with spatial navigation.

amygdala

A subcortical forebrain structure involved in detecting and responding to threats; it also plays a vital role in learning to associate things with emotional responses and in processing emotional information.

occipital lobes

Regions of the cerebral cortex at the back of the brain important for vision

parietal lobes

Regions of the cerebral cortex in front of the occipital lobes and behind the frontal lobes important for the sense of touch and for picturing the layout of spaces in an environment.

temporal lobes

Regions of the cerebral cortex below the parietal lobes and in front of the occipital lobes important for hearing and for recognizing objects, such as faces.

frontal lobes

Regions of the cerebral cortex at the front of the brain; important for movement, planning, and complex processes (rational thought, attention, self-control, social processes, and so on).

split brain

A condition in which the corpus callosum is surgically severed and the two hemispheres of the brain do not receive information directly from each other.

somatic nervous system

A subdivision of the PNS; it transmits sensory signals and motor signals back and forth between the CNS and the skin, muscles, and joints.

autonomic nervous system

A subdivision of the PNS; it transmits sensory signals and motor signals back and forth between the CNS and the body's glands and internal organs.

endocrine system

A bodily communication system that uses hormones to influence many aspects of the body, mental activity, and behavior.

hormones

Chemicals released from endocrine glands that travel through the bloodstream to targeted tissues; the tissues are later influenced by the hormones.

natural selection

The basis of evolution; the idea that those who inherit characteristics that help them adapt to their particular environments have an advantage over those who do not.

genes

Units of heredity that help determine an offspring's characteristics.

monozygotic twins

Identical twins; these siblings result from one zygote splitting in two, so they share the same genes.

dizygotic twins

Fraternal twins; these siblings result from two separately fertilized eggs, so they are no more similar genetically than nontwin siblings are.

plasticity

A property of the brain that causes it to change as a result of experience or injury.