Chapter 3

Front 1

neuron

Back 1

specialized cell in the nervous system that accumulates and transmits information

Front 2

dendrites

Back 2

branched part of a neuron that receives impulses and conducts them toward the cell body

Front 3

cell body

Back 3

portion of the neuron containing the metabolic machinery that keeps the cell alive and functional

Front 4

axon

Back 4

part of a neuron that transmits impulses to glands, muscles, or other neurons

Front 5

efferent neurons

Back 5

nerves that carry messages outward from the central nervous system

Front 6

afferent neurons

Back 6

nerves that carry messages inward toward the central nervous system;keep system informed about internal and external world

Front 7

interneurons

Back 7

neurons that are neither afferent nor efferent, but instead carry information from one neuron to another; "local connection"

Front 8

projection neurons

Back 8

in the brain link one area of central nervous system to another area

Front 9

glia

Back 9

type of cell in the nervous system long believed to provide a "support" function for neurons; recent research indicates that glia provide many other functions as well; provide and control nourishment for neurons; convert glucose to lactate; increase blood flow when neurons in brain become more active

Front 10

myelin

Back 10

fatty substance that makes up some types of glial cells; these cells wrap around the axon of some neurons, providing an insulating "myelin sheath" around these neurons

Front 11

action potential

Back 11

a brief change in the electrical charge of a neuronal membrane; the physical basis of the signal that travels the length of the neuron

Front 12

resting potential

Back 12

the voltage difference between the inside and the outside of a neuronal membrane when the neuron is not firing; -70 millivolts

Front 13

excitation threshold

Back 13

the voltage difference between a neuron's interior and exterior that, if exceeded, causes the neuron to fire; about -55 millivolts in mammals

Front 14

refractory period

Back 14

the time after an action potential during which a neuron's cell membrane is unprepared for the next action potential

Front 15

depolarize

Back 15

in the nervous system, to lose the charge that normally exists across the neuronal membrane

Front 16

propagation

Back 16

the spread of the action potenial down an axon, caused by successive changes in electrical charge along the length of the axon's membrane

Front 17

ion pump

Back 17

actively pump ions into or out of the cell

Na+ out (3)/K+ in (2)

Front 18

ion channel

Back 18

passageways through membrane; must be open to let specific ions pass

Front 19

neuron at resting

Back 19

more K+ ions outside the cell; Na+ barely able to pass through the channels; K+ flow freely through the channels (generally outward)

Front 20

neuron stimulation

Back 20

new set of ion channels open (Na+), ions flood into the cell creating an excess of positive ions inside the membrane, sodium pumps resume evacuation of Na+ to outside and sodium channels close up to return to resting

Front 21

if an axon is myelinated

Back 21

ions can only move in and out at the nodes of ranvier, action potential "skips" from node to node=>moves quickly

Front 22

all-or-none law

Back 22

the law that all action potentials have the same strength and speed regardless of the triggering stimulus

Front 23

synapse

Back 23

the small gap between two adjacent neurons, consisting of the presynaptic and postsynaptic neurons' membranes and the space between them

Front 24

neurotransmitters

Back 24

chemicals released by one neuron (usually the presynaptic neuron), which triggers a response in another neuron (usually the postsynaptic neuron); the chief means of communication among neurons

Front 25

synaptic reuptake

Back 25

the presynaptic neuron's process of reabsorbing its own neurotransmitters after signaling so that they can be released again the next time the neuron fires

Front 26

agonists

Back 26

drugs that enhance a neurotransmitter's activity

Front 27

antagonists

Back 27

drugs that impede the activity of a neurotransmitter

Front 28

blood-brain barrier

Back 28

specialized membranes that surround the blood vessels within the brain and filter harmful chemicals out of the brain's blood supply

Front 29

anterior pituitary

Back 29

triggers hormone secretion in many of the other endocrine glands

Front 30

posterior pituitary

Back 30

prevents loss of water through kidney

Front 31

thyroid

Back 31

affects metabolic rate

Front 32

islet cells in pancreas

Back 32

affects utilization of glucose

Front 33

adrenal cortex

Back 33

various effects on metabolism, immunity, and response to stress;has some effects on sexual behavior

Front 34

ovaries

Back 34

one set of hormones (estrogen) produces female sex characteristics and is relevant to sexual behavior; another hormone (progesterone) prepares uterus for implantation of embryo

Front 35

testes

Back 35

produces male sex characteristics; relevant to sexual arousal

Front 36

Acetylcholine(ACh)

Back 36

releases at many synapses and at the junction between nerves and muscles; the released of ACh makes the muscle fibers contract

Front 37

Serotonin (5HT)

Back 37

involved in many of the mechanisms of sleep, mood, and arousal

Front 38

Gamma-amino butyric acid (GABA)

Back 38

the most widely distributed inhibitory transmitter of the central nervous system

Front 39

Glutamate

Back 39

perhaps the major excitatory transmitter in the brain; plays a crucial role in learning and memory

Front 40

Norepinephrine (NE)

Back 40

helps control arousal level; influences wakefulness, learning, and memory

Front 41

Dopamine (DA)

Back 41

influences movement, motivation, emotion

Front 42

endocrine system

Back 42

system of glands that release secretions directly into the bloodstream and affect organs elsewhere in the body

pineal, hypothalamus, pituitary, thyroid, parathyriod, thymus, adrenal, pancreas, ovary, tesis

Front 43

hormone

Back 43

a chemical released by a gland. hormones travel through the bloodstream and influence functions such as metabolic rate, arousal level, and the liver's sugar output

Front 44

brain lesion

Back 44

use stronger electrical current to damage brain cells

Front 45

transecting

Back 45

disrupt flow of information into or out of an area by cutting the pathways

Front 46

aphasia

Back 46

disruption of language use caused by brain damage

Front 47

transcranial magnetic stimulation (TMS)

Back 47

the technique of applying repeated magnetic stimulation at the surface of the skull to temporarily stimulate or disable a target brain region

Front 48

electroencephalogram(EEG)

Back 48

a record of the brain's electrical activity by placing electrodes on the scalp
tells us if there is a detectable rhythm in brain activity

Front 49

event-related potential (ERP)

Back 49

electrical changes in the brain that correspond to the brain's response to a specific event; measured with EEG

Front 50

CT Scan (computerized tomography)

Back 50

a technique for examining brain structure by constructing a composite of X-ray images taken from many different angles; shows the exact shape and position of structures; important for identifying tumors, structural abnormalities and research

Front 51

MRI (magnetic resonance imaging)

Back 51

a neuroimaging technique that documents the effect of strong magnetic pulses on the molecules that make up brain tissue. a computer then assembles this information into a picture of brain structure;can show tumors, tissue degeneration, blood clots or leaks

1. put into a strong magnetic field which aligns spinning of nuclei
2. brief pulse disrupts the spin
3. spin shift back into alignment
4. shift gives off electromagnetic energy that is recorded
5. computer creates a picture

Front 52

PET Scan (positron emission tomography)

Back 52

a technique for examining brain function by observing the amount of metabolic activity in different brain regions

1. participant is injected with radioisotope that mimics glucose
2. the scan keeps track of how the radioactivity is distributed in the brain

*idea is that brain cells that are more active will use more glucose and absorb more radioactivity

Front 53

Functional MRI Scan (fMRI)

Back 53

a technique for examining brain function by measuring blood flow and oxygen use within the brain

-rely on hemoglobin carrying oxygen to the brain, less sensitive to magnetism when carrying oxygen
-keep track of hemoglobin=>measure blood oxygenation level dependent signal (BOLD)
-in especially active regions the ration increases
-measurement across a couple of seconds

Front 54

central nervous system (CNS)

Back 54

the brain and spinal chord

Front 55

peripheral nervous system (PNS)

Back 55

the afferent and efferent nerves that extend from the brain and spinal chord to connect them with the organs and muscles

Front 56

somatic nervous system (SNS)

Back 56

the division of the peripheral nervous system that controls the skeletal muscles and transmits sensory information

Front 57

autonomic nervous system (ANS)

Back 57

the division of the peripheral nervous system that receives information from and controls the internal organs

Front 58

sympathetic branch

Back 58

the division of the autonomic nervous system that mobilizes the organism for physical exertion

Front 59

parasympathetic branch

Back 59

the division of the autonomic nervous system that restores the body's normal resting state and conserves energy

Front 60

brain stem

Back 60

the brain region at the top of the spinal chord that includes the medulla (controls breathing, blood circulation, maintains our balance by controlling head and limb position) and the pons (controls the brain's overall level of attentiveness and helps govern timing of sleep and dreaming)

Front 61

cerebellum

Back 61

the part of the brain the controls muscular coordination and equilibrium; damage can cause problems in spacial reasoning

Front 62

cerebral cortex

Back 62

the outermost layer of the forebrain; thin covering; about 80 percent of the human brain; creates the wrinkles/convolutions

Front 63

cerebral hemisphere

Back 63

one-half (left or right) of the cerebrum, the topmost part of the brain

Front 64

frontal lobe

Back 64

the area at the front of each cerebral hemisphere; includes tissue crucial for many aspects of planning and controlling thoughts and behavior

Front 65

parietal lobe

Back 65

the area in each cerebral hemisphere that lies between the frontal and occipital lobes; includes tissue crucial for receiving information from the skin senses

Front 66

temporal lobe

Back 66

the areas in each cerebral hemisphere lying below the temples; includes tissue crucial for hearing and many aspects of language use

Front 67

occipital lobe

Back 67

the rearmost area of each cerebral hemisphere; includes tissue crucial for processing visual information

Front 68

hypothalamus

Back 68

a subcortical structure that plays a vital role in controlling many motivated behaviors, like eating, drinking, and sexual activity

Front 69

limbic system

Back 69

a group of interconnected structures (including the hypothalamus, the amygdala, and others) that are crucial for emotion, motivation, and many aspects of leaning and memory

Front 70

amygdala

Back 70

an almond-shaped, temporal lobe structure that plays a central role in emotion and evaluating stimuli

Front 71

hippocampus

Back 71

a temporal lobe structure that plays a pivotal role in learning and forming new memories

Front 72

lateralization

Back 72

functional differences between the two cerebral hemispheres

influences include: language use, perception and understanding of spacial organization

Front 73

corpus callosum

Back 73

the thick bundle of fibers connecting the cerebral hemispheres; the largest commissure

Front 74

projection areas

Back 74

areas in which the brain tissue seems to form a "map" of sensory information

Front 75

contralateral control

Back 75

the typical pattern in vertebrates in which movements of the right side of the body are controlled by the left hemisphere, while movements of the left side are controlled by the right hemisphere

Front 76

apraxia

Back 76

a serious disturbance in beginning or carrying out voluntary movements

Front 77

visual agnosia

Back 77

the inability to recognize a visual stimulus despite the ability to see and describe it

Front 78

neglect syndrome

Back 78

the result of certain right parietal lobe lesions that leave a patient completely inattentive to stimuli to her left, including the left side of her own body

Front 79

aphasia

Back 79

any of a number of linguistic disorders caused by injury to or malformation of the brain

Front 80

prefrontal area

Back 80

the frontmost portion of the frontal lobes. involved in working memory, strategy formation, and response inhibition

Front 81

executive control

Back 81

processes such as making plans or overriding habitual responses that let the brain direct its own cognitive activities

Front 82

perseveration

Back 82

the tendency to repeat a response inappropriately; often a result of deficits in executive control caused by prefrontal lesions

Front 83

brain plasticity

Back 83

the capacity for the brain to alter its structure and function

Front 84

commissure

Back 84

thick bundles of fibers that carry info back and forth from the two hemispheres