Biopsych Neuronal Impulses And Propogation

Front 1

axon hillock

Back 1

point at which excitatory and inhibitory inputs are integrated

Front 2

order of impulse

Back 2

1. action potential shoots down the axon
2. neurotransmitters are released into the synapse, changing the membrane potential of the dendrite
3. if the depolarization is strong enough, it spreads down the dendrite and across the cell body
4. if threshold is reached, the cell fires, shooting an action potential down the axon

Front 3

electrical gradient

Back 3

maintained int he membrane of a neuron; difference in electrical charge inside relative to the outside of the cell - protein channels permit certain ions to cross through the membrane at a controlled rate

Front 4

membrane potential

Back 4

reason neurons can respond to stimuli and conduct impulses; unequal distribution of ions on the two sides of a neuronal cell membrane

Front 5

resting potential

Back 5

the inside of a neuron is slightly negative relative to the outside (-70 millivolts)

Front 6

protein anions are ___ charged can/cannot pass though membrane

Back 6

negatively charged - too large to pass through

Front 7

When membrane is at rest:

Back 7

Na+ channels closed
K+ channes are partially closed allowing the slow pass of K+. Some passage of K+ comes inward to due electrical attraction, but more K+ leaks out down the concentration gradient.

Front 8

electrical polarization is maintained due to the:

Back 8

1. anions
2. K+ concentration gradient
3. Na+/K+ pump

Front 9

Sodium-potassium pump

Back 9

protein complex that continually pumps 3 sodium ions out of the cell, while drawing 2 potassium ions into the cell to help maintain the electrical gradient; energy required since they are going againt their concentration gradient

Front 10

hyperpolarization

Back 10

due to an efflux of K+ ions (or an influx of Cl- ions) making the inside more negative

Front 11

depolarization

Back 11

due to an influx of Na+ ions - reversal of usual polarity (action potential)

Front 12

graded potentials typically occur (where)

Back 12

on the dendrites and soma

Front 13

action potential

Back 13

any stimulation beyond a certain level (threshold) produces a sudden massive depolarization

Front 14

voltage-activated channels

Back 14

membrane channels whose permeability depends on the voltage difference across the membrane

Front 15

after action potential

Back 15

Na+ channels quickly close
K+ channels open and K+ flows out due to concentration gradient and take with them their positive charge

Front 16

all-or-none law

Back 16

the amplitude and velocity of the AP are indpendent of the intensity of the stimulus that initiated the AP

Front 17

refractory period

Back 17

after an AP, a neuron resists the production of another AP

Front 18

absolute refractory period

Back 18

membrane CANNOT produce an AP

Front 19

relative refractory period

Back 19

takes a stronger than usual stimulus to trigger an AP

Front 20

neuronal impulse

Back 20

electrical message that is transmitted down the axon of a neuron

Front 21

saltatory conduction

Back 21

"jumping" of the action potential from node to node (provides rapid confduction of impulses, conserves energy for cell)

Front 22

Charles Scott Sherrington

Back 22

coined the term "synapse" by studying reflexes - the speed of conduction through a reflex arc is slower and more variable; delay occurs at the synapse

Front 23

temporal summation

Back 23

repeated stimuli can havea cumulative effect and can produce an action potential, if the EPSP combination exceeds the threshold

Front 24

spatial summation

Back 24

synaptic input from several locations can have a cumulative effect and tigger an action potential

Front 25

inhibitory post-synaptic potential (IPSP)

Back 25

synaptic input selectively opens teh gates fropostively charged potassium ions to leave the cell or for negatively charged cholride ions to enter the cels - serves as active "brake" that suppresses excitation

Front 26

recipricol innervation

Back 26

as one muscle is stimulated, the other is inhibited

Front 27

John Carew Eccles

Back 27

discovery of neurotransmitters - bind to receptors on the post-synaptic membrane and induce a graded potential

Front 28

arrival of the action potential into the axonal ending triggers an influx of ___

Back 28

Ca2+ ions, which induces the migration of transmitter-filled vesicles toward the pre-synaptic membrane (pinocytosis)

Front 29

exocytosis

Back 29

excretion of the neurotransmitter from the presynaptic terminal into the synapse; the synaptic vesicles fuse wth the membrane and rupture releasing their contents into the synapse

Front 30

activated receptors

Back 30

have a bound neurotransmitter and triggers ion channels to open in te receiving cell's membrane, allowing ions to flood across, changing the electrical potential across the post-synaptic membrane

Front 31

peripheral nervous system

Back 31

somatic (voluntary) & autonomic (involuntary)

Front 32

autonomic

Back 32

sympathetic and parasympathetic

Front 33

sympathetic

Back 33

comprised of ganglia on the left and right of the spinal cord - short preganglionic axons from the spinal cord and long postganglionic fibers synapsing on organs; mainly uses norepinephrine

Front 34

parasympathetic

Back 34

long preganglionic acons extending from the spinal cord and short postganglionic fibers that attach to the organs themselves; mainly use acetylcholine

Front 35

Forebrain includes the:

Back 35

Telencephalon and Diencephalon

Front 36

Midbrain includes the:

Back 36

Mesencephalon

Front 37

Hindbrain includes the:

Back 37

Metencephalon and Myelencephalon

Front 38

Telencephalon includes the:

Back 38

Corpus Calosum
Basal ganglia
Cerebrum (cerebral cortex)
Limbic System

Front 39

Diencephalon includes the:

Back 39

Thalamus
Hypothalamus

Front 40

Midbrain includes the:

Back 40

Superior colliculi
Inferior colliculi

Front 41

Hindbrain includes the:

Back 41

Cerebellum
Pons
Medulla

Front 42

Corpus Callosum

Back 42

bridge of fibers passing information between the two cerebral hemispheres

Front 43

Basal Ganglia

Back 43

planning of movement and aspects of memory and emotional expression - comprised of caudate nucleus, putamen, and globus pallidus

Front 44

Cereral Cortex

Back 44

sensing, thinking, learning, emotion, consciousness, voluntary movement

Front 45

Limbic System

Back 45

interlinked structures that form a border around the brainstem - mediates motivation, emotion, drives, and aggression; includes the olfactory bulb, hypothalamus, hippocampus, amygdala, cingulate gyrus of the cerebral cortex

Front 46

Thalamus

Back 46

relay center for cortex; handles incoming and outgoing signals

Front 47

hypothalamus

Back 47

regulates basic biological needs: hunger, thirst, temperature; conveys messages to the pituitary gland to alter the release of hormones influencing the endocrine organs

Front 48

cerebellum

Back 48

coordinates fine muscle movement, balance

Front 49

pons

Back 49

involved in sleep and arousal

Front 50

medulla

Back 50

regulates largely unconscious functions such as breathing and circulation

Front 51

longitudinal fissure

Back 51

separates hemispheres of the cerebral cortex

Front 52

corpus callosum

Back 52

bundle of axons which allows for inter-hemispheric communication

Front 53

Cerebral Cortex organization

Back 53

contained within a 1/4 inch layer of cells at the surface of the brain; contains p to 6 distinct laminae that are parallel to the surface of the cortex - cells divided into colums that lie perpendicular to laminae
4 lobes: occipital, parietal, temporal, frontal

Front 54

Alzheimer's

Back 54

due in part to a degeneration of cells in the nucleus basalis of the forebrain that use Ach

Front 55

primary cortex

Back 55

in each lobe of cerebral cortex; provides inital processing resulting in 'awareness'

Front 56

secondary cortexq

Back 56

in each lobe of cerebral cortex; does more in-depth processing resulting in 'comprehension'

Front 57

Einstein's Area

Back 57

angualr gyrus: metaphorical and abstract thinking

Front 58

flow of information through the cortex

Back 58

sensory info from body > primary somatosensory cortex > sensory association cortex > motor asociation cortex > movement of muscles

Front 59

Broca's Aphasia

Back 59

speech production deficit unrelated to auditory dysfunction

Front 60

Wernicke's Aphasia

Back 60

speech comprehension deficit unrelated to auditory dysfunction