Psy 110 Chapter 2

Front 1

Neuron

Back 1

A cell that receives signals from other neurons or sense organs, processes these signals, and sends the signals to other neurons, muscles, or organs; the basic unit of the nervous system.

Front 2

Sensory Neuron

Back 2

A neuron that responds to input from sense organs.

Front 3

Motor Neuron

Back 3

A neuron that sends signals to muscles to control movement.

Front 4

Interneuron

Back 4

A neuron that is connected to other neurons, not to sense organs or muscles.

Front 5

Brain Circuit

Back 5

A set of neurons that affect one another.

Front 6

Cell Body

Back 6

The central part of a neuron (or other cell), which contains the nucleus.

Front 7

Cell Membrane

Back 7

The skin of a cell

Front 8

Axon

Back 8

The sending end of the neuron; the long cable-like structure extending from the cell body.

Front 9

Terminal Button

Back 9

A structure at the end of a branch of an axon that, when the neuron is triggered, releases chemicals into the space between neurons.

Front 10

Dendrite

Back 10

The treelike part of a neuron that receives messages from the axons of other neurons.

Front 11

Resting Potential

Back 11

The negative charge within a neuron when it is at rest.

Front 12

Ion

Back 12

An atom that has a positive or negative charge.

Front 13

Action Potential

Back 13

The shifting change in charge that moves down the axon.

Front 14

All-Or-None Law

Back 14

States that if the neuron is sufficiently stimulated, it fires, sending the action potential all the way down the axon and releasing chemicals from the terminal buttons; either the action potential occurs or it doesn’t.

Front 15

Myelin

Back 15

A fatty substance that helps impulses travel down the axon more efficiently.

Front 16

Synapse

Back 16

The place where an axon of one neuron can send signals to the membrane (on a dendrite or cell body) of another neuron.

Front 17

Synaptic Cleft

Back 17

The gap between the axon of one neuron and the membrane of another, across which communication occurs.

Front 18

Neurotransmitter

Back 18

A chemical that carries a signal from the terminal button on one neuron to the dendrite or cell body of another.

Front 19

Neuromodulator

Back 19

A chemical that alters the effect of a neurotransmitter.

Front 20

Endogenous Cannabinoids

Back 20

Neuromodulators released by the receiving neuron that then influence the activity of the sending neuron.

Front 21

Receptor

Back 21

A site on a dendrite or cell body where a messenger molecule attaches itself; like a lock that is opened by one key, a receptor receives only one type of neurotransmitter or neuromodulator.

Front 22

Reuptake

Back 22

The process by which surplus neurotransmitter is reabsorbed back into the sending neuron so that the neuron can effectively fire again.

Front 23

Agonist

Back 23

A chemical that mimics the effects of a neurotransmitter by activating a type of receptor.

Front 24

Selective Serotonin-Reuptake Inhibitor (SSRI)

Back 24

A chemical that blocks the reuptake of the neurotransmitter serotonin.

Front 25

Antagonist

Back 25

A chemical that interferes with the effect of a neurotransmitter (often by blocking a receptor).

Front 26

Glial Cell

Back 26

A type of cell that surrounds neurons, influences the communication amoung neurons, and generally helps in the “care and feeding” of neurons.

Front 27

Peripheral Nervous System (PNS)

Back 27

The autonomic nervous system and the sensory-somatic nervous system.

Front 28

Autonomic Nervous System (ANS)

Back 28

Controls the smooth muscles in the body, some glandular functions, and many of the body’s self-regulating activities, such as digestion and circulation.

Front 29

Sympathetic Nervous System

Back 29

Part of the ANS that readies an animal to fight or to flee by speeding up the heart, increasing breathing rate to deliver more oxygen, dilating the pupils, producing sweat, decreasing salivation, inhibiting activity in the stomach, and relaxing the bladder.

Front 30

Parasympathetic Nervous System

Back 30

Part of the ANS that is “next to” the sympathetic system and that tends to counteract its effects.

Front 31

Sensory-Somatic Nervous System (SSNS)

Back 31

Part of the PNS that consists of neurons in the sensory organs (such as the eyes and ears) that convey information to the brain, as well as neurons that actually trigger muscles and glands.

Front 32

Skeletal System

Back 32

Consists of nerves that are attached to striated muscles.

Front 33

Spinal Cord

Back 33

The flexible rope of nerves that runs inside the backbone, or spinal column.

Front 34

Central Nervous System (CNS)

Back 34

The spinal cord and the brain.

Front 35

Reflex

Back 35

An automatic response to an event.

Front 36

Meninges

Back 36

Membranes that cover the brain.

Front 37

Cerebral Hemisphere

Back 37

A left or right half brain, shaped roughly like half a sphere.

Front 38

Lobes

Back 38

The four major parts of each cerebral hemisphere—occipital, temporal, parietal, and frontal.

Front 39

Corpus Callosum

Back 39

The large band of nerve fibers that connects the two halves of the brain.

Front 40

Cerebral Cortex

Back 40

The convoluted pinkish-gray outer layer of the brain, where most mental processes take place.

Front 41

Sulcus

Back 41

A crease in the cerebral cortex.

Front 42

Gyrus

Back 42

A bulge between sulci in the cerebral cortex.

Front 43

Subcortical Structures

Back 43

Parts of the brain located under the cerebral cortex and beneath the ventricles.

Front 44

Occipital Lobe

Back 44

The brain lobe at the back of the head; concerned entirely with different aspects of vision.

Front 45

Temporal Lobe

Back 45

The brain lobe under the temples, in front of the ears, where sideburns begin to grow down; among its many functions are visual memory and hearing.

Front 46

Parietal Lobe

Back 46

The brain lobe across the top part of the brain behind the ears, which is involved in registering spatial location, attention, and motor control.

Front 47

Somatosensory Strip

Back 47

The brain area, located immediately behind the central sulcus, that registers sensation on the body and is organized by body part.

Front 48

Frontal Lobe

Back 48

The brain lobe located behind the forehead; the seat of planning, memory search, motor control, and reasoning, as well as numerous other functions.

Front 49

Motor Strip

Back 49

The brain area, located immediately in front of the central sulcus, that controls fine movements and is organized by body part; also called primary motor cortex.

Front 50

Split-Brain Patient

Back 50

A person whose corpus callosum has been severed for medical reasons, so that neuronal impulses no longer pass from one hemisphere to the other.

Front 51

Forebrain

Back 51

The cortex, thalamus, limbic system, and basal ganglia.

Front 52

Thalamus

Back 52

A subcortical structure that receives inputs from sensory and motor systems and plays a crucial role in attention; often thought of as a switching center.

Front 53

Hypothalamus

Back 53

A brain structure that sits under the thalamus and plays a central role in controlling eating and drinking and in regulating the body’s temperature, blood pressure, and heart rate.

Front 54

Hippocampus

Back 54

A subcortical structure that plays a key role in allowing new information to be stored in the brain’s memory banks.

Front 55

Amygdala

Back 55

A subcortical structure that plays a special role in fear and is involved in other sorts of emotions, such as anger.

Front 56

Limbic System

Back 56

A set of brain areas, including the hippocampus, amygdale, and other areas, that have long been thought of as being involved in fighting, fleeing, feeding, and sex.

Front 57

Basal Ganglia

Back 57

Subcortical structures that play a role in planning and producing movement.

Front 58

Brainstem

Back 58

The set of neural structures at the base of the brain, including the medulla and pons.

Front 59

Medulla

Back 59

The lowest part of the lower brainstem, which plays a central role in automatic control of breathing, swallowing, and blood circulation.

Front 60

Reticular Formation

Back 60

A collection of small structures in the brainstem, organized into two main parts: the “ascending” part plays a key role in keeping a person awake and alert; the “descending” part is important in producing autonomic nervous system reactions.

Front 61

Hormone

Back 61

A chemical that is produced by a gland and can act as a neuromodulator.

Front 62

Neuroendocrine System

Back 62

The system, regulated by the CNS, that makes hormones that affect many bodily functions and that also provides the CNS with information.

Front 63

Testosterone

Back 63

The hormone that causes males to develop facial hair and other sex characteristics and to build up muscle volume.

Front 64

Estrogen

Back 64

The hormone that causes breasts to develop and is involved in the menstrual cycle.

Front 65

Cortisol

Back 65

A hormone produced by the outer layer of the adrenal glands that helps with body cope with the extra energy demands of stress by breaking down and converting protein and fat to sugar.

Front 66

Pituitary Gland

Back 66

The “master gland” that regulates other glands but is itself controlled by the brain, primarily via connections from the hypothalamus.

Front 67

Hypothalamic-Pituitary-Adrenal (HPA) Axis

Back 67

The hypothalamus, pituitary gland, and adrenal glands, which work together to fight off infection.

Front 68

Lesion

Back 68

A region of impaired tissue.

Front 69

Stroke

Back 69

A source of brain damage that occurs when blood (with its life-giving nutrients and oxygen) fails to reach part of the brain, causing neurons in that area to die.

Front 70

Electroencephalograph

Back 70

A machine that records electrical current produced by the brain.

Front 71

Electroencephalogram (EEG)

Back 71

A recording from the scalp of electrical activity in the brain over time, which produces a tracing of pulses at different frequencies.

Front 72

Magnetoencephalography (MEG)

Back 72

A technique for assessing brain activity that relies on recording magnetic waves from outside of the head.

Front 73

Microelectrode

Back 73

A tiny probe inserted into the brain to record the electrical activity of individual neurons.

Front 74

Neuroimaging

Back 74

Brain-scanning techniques that produce a picture of the structure or functioning of neurons.

Front 75

Computer-Assisted Tomography (CT, formerly CAT)

Back 75

A neuroimaging technique that produces a three-dimensional image of brain structures using X rays.

Front 76

Magnetic Resonance Imaging (MRI)

Back 76

A technique that uses magnetic properties of atoms to take sharp pictures of the structures of the brain.

Front 77

Positron Emission Tomography (PET)

Back 77

A neuroimaging technique that uses small amounts of a radioactive substance to track blood flow or energy consumption in the brain.

Front 78

Functional Magnetic Resonance Imaging (fMRI)

Back 78

A type of MRI that usually detects the amount of oxygen being brought to a particular place in the brain while a task is being performed.

Front 79

Transcranial Magnetic Stimulation (TMS)

Back 79

A technique in which the brain is stimulated from outside by putting a wire coil on a person’s head and delivering a magnetic pulse. The magnetic fields are so strong that they make neurons under the coil fire.

Front 80

Mendelian Inheritance

Back 80

The transmission of characteristics by individual elements of inheritance (genes), each acting separately.

Front 81

Deoxyribonucleic Acid (DNA)

Back 81

A molecule that contains genes.

Front 82

Gene

Back 82

A stretch of DNA that produces a specific protein.

Front 83

Genotype

Back 83

The genetic code within an organism.

Front 84

Phenotype

Back 84

The observable structure and behavior of an organism.

Front 85

Complex Inheritance

Back 85

The joint action of combinations of genes working together.

Front 86

Pruning

Back 86

A process whereby certain connections among neurons are eliminated.

Front 87

Plasticity

Back 87

The brain’s ability to be molded by experience.

Front 88

Passive Interaction

Back 88

Occurs when genetically shaped tendencies of parents or siblings produce an environment that is passively received by the child.

Front 89

Evocative (Or Reactive) Interaction

Back 89

Occurs when genetically influenced characteristics draw out behaviors from other people.

Front 90

Active Interaction

Back 90

Occurs when people choose, partly based on genetic tendencies, to put themselves in specific situations and to avoid others.

Front 91

Behavioral Genetics

Back 91

The field in which researchers attempt to determine the extent to which the differences among people are due to their genes or to the environment.

Front 92

Heritability

Back 92

The degree to which variability in a characteristic is due to genetics.

Front 93

Twin Study

Back 93

A study that compares identical and fraternal twins to determine the relative contribution of genes to variability in a trait or characteristic.

Front 94

Monozygotic

Back 94

From the same egg and having identical genes.

Front 95

Dizygotic

Back 95

From different eggs and sharing only as many genes as any pair of brothers or sisters—on average, half.

Front 96

Adoption Study

Back 96

A study in which characteristics of children adopted at birth are compared to those of their adoptive parents or siblings versus their biological parents or siblings (often twins). These studies often focus on comparisons of twins who were raised in the same household and twins raised in different households.

Front 97

Evolution

Back 97

Gene-based changes in the characteristics of members of a species over successive generations.

Front 98

Natural Selection

Back 98

Changes in the frequency of genes in a population that arise because genes allow an organism to have more offspring that survive.

Front 99

Adaptation

Back 99

A characteristic that increases an organism’s fitness for an environment.