Nervous System

Front 1

Location where action potential is generated

Back 1

axon hillock, then carried down axon to synapse

Front 2

resting potential

Back 2

established by equilibrium between passive diffusion of ions across the membrane of the Na/K pump; 3 Na pumped out for every 2 K pumped in. eventually inside is more negative

Front 3

resting potential

Back 3

-70mV

Front 4

membrane at rest

Back 4

-70mV and Na and K channels are closed

Front 5

Depolarization

Back 5

Na channel open, and Na starts to enter

Front 6

K channels begin to open as Na starts to close

Back 6

still part of depolarization

Front 7

repolarization

Back 7

Na channels closed, K channels begin to repolarize the membrane

Front 8

Hyperpolaization

Back 8

cell is too negative

Front 9

K channels close

Back 9

membrane equilibriates to resting potential

Front 10

action potential

Back 10

all or notheing,membrane completely depolarizes, or no action potential is generated; stimulus to membrane must be greater than the threshold stimulus

Front 11

absolute refractory period

Back 11

once action potential begins, no stimulus will create another action potnetial

Front 12

synapse

Back 12

neural impulses are transmitted from one cell to another chemically or eleectrically; transmission from one cell to another is the slowest part of the process of cellular commuication in nervouse system

Front 13

electrical synapse

Back 13

uncommon; composed of gap junctions between cells, cardiac muscle is an example; much faster and bidirectional compared to chemical synapse

Front 14

chemical synapse

Back 14

more common; unidirectional; when action potentical comes, Ca released from vesicales and causes neurotransmitter vesicles to be released via exocytosis into synaptic ; neurotransmitter diffuses via brownian motion in synaptic cleft; Postsynaptic membrane has receptors for the nuerotranmitters which then allow ions to move across posttynaptic membarane via protein ionophosres; completes neural impulse and not attenuated

Front 15

neurotransmitter ataches to its receptor momentarily

Back 15

if it remains in the synaptic cleft, it may cause nerve to repeat firing, so its recycled, destroyed via enzyme or reabsorbed by presynaptic cell via active transport

Front 16

neurotransmitters

Back 16

may be inhibitory or excitatory, but not both. However, some neurotramsitters like acetylcoline may behave depedning on the receptor (inhibit in heart, excite n intestine)

Front 17

receptors in postynaptic membrane

Back 17

maybe ion channels (opening with respective neurotransmitter) or may act via 2nd messenger system

Front 18

second messenger system

Back 18

activates another molecule insidee the cell to make changes (usually more long term as involved in memory)

Front 19

G-protein

Back 19

commonly initiate 2nd messenger; attached to receptor protein along the inside of the postynaptic membrane; when recepor stimulate by neurotransmitter, part of G-protein (called alpha subunit) breaks free; alpha subunit may: activate seperate specific ion channels, activatve second messengaer (cAMP) activalte intracellular enzymes, activate gene transcription

Front 20

slowest step in transfer of nervouse signal

Back 20

chemcial synapse, unidirectional

Front 21

glial or neuroglial

Back 21

support cells

Front 22

more glialcells than neurons

Back 22

10:1

Front 23

neuroglia

Back 23

able to divide

Front 24

myelinated axons

Back 24

only vertebrates have

Front 25

astrocyte

Back 25

type of glial cell used in support

Front 26

oligodendrovytes

Back 26

glial cells that wrap many times around axons in CNS creating myelin sheath

Front 27

schwann cells

Back 27

where myelin produced in peripheral NS

Front 28

myelin

Back 28

increases rate at which axon can transmit signal

Front 29

white matter

Back 29

myelinated axon

Front 30

gray matter

Back 30

unmyelinated cell body

Front 31

node of ranvier

Back 31

space between myeline

Front 32

saltatory conduction

Back 32

action potential jumps from one node of ranvier to the other

Front 33

acetycholinesterase

Back 33

enzyme that degrades acetylcholine

Front 34

3 types of neurons

Back 34

sensory neuron, (afferent neuron), interneuron, motor (efferent) neuron

Front 35

sensory (afferent) neuron

Back 35

receive signals from a receptor that interacts with ints enviornment, sensory bneuron transfer signal to other neurons (99 % os sensory input is discarded by brain)

Front 36

interneurons

Back 36

tansfer signals from neuron to neuron; 90% of neurons are interneuron

Front 37

motor (efferent) neuron

Back 37

carries signal to a muscle or gland called the effecotr

Front 38

nerves

Back 38

neuron processes ound together

Front 39

CNS

Back 39

functions to integrate nervous signals between sensory and motor neurons

Front 40

PNS

Back 40

divides into somatic nervous system and autonomic nervous system

Front 41

somatic

Back 41

voluntary, conscously ccontrolled, designed to respnse to external environemnt; neurons synapse directly on their effecots; use acetycholine as neurotransmitter

Front 42

autonomic

Back 42

primarily receives signals from viscera (organs) then to smooth muscle, cardiac, and glands; generally involuntary; divided into sympathetic and parasympathetic

Front 43

sympathetic ANS

Back 43

fight or flight (heart beat, constrict blood around organs to increase for muscle)

Front 44

parasympathetic ANS

Back 44

rest and digest; slows heart and increases digestive andexcretory activity

Front 45

ganglion

Back 45

cell bodies outside of CNS

Front 46

nucleus

Back 46

cell bodies inside CNS

Front 47

sympathetic signals

Back 47

originate in neurons founds in spinal cord

Front 48

parasympathetic signals

Back 48

originate in neurons founds in spinal cord and brain

Front 49

acetylcholine

Back 49

neurotransmitter used by all preganglionic neurons in ANS (autonomic nervous system) and by postsynaptic system parasympathetic nervous system (rest and digest)

Front 50

epinephrine or norepinephrine (also adrenaline or noradrenaline)

Back 50

used by post ganglionic neurons in the sympathetic (fight or flight) nervous system

Front 51

aceytcholine receptors

Back 51

cholinerigic receptors : nicotinic and muscarinic

Front 52

somatic nervous system

Back 52

innervates skeletal muscles (voluntary)

Front 53

autonomic nervous system

Back 53

innervates cardiace and smooth muscles, some glands tool involuntary

Front 54

neurotransmitter relatedx to somatic and parasympathetic

Back 54

acetylcholine

Front 55

neurotransmitter related to sympathetic nervous system (fight or flight)

Back 55

noreponephrine and epinephrine)

Front 56

lower brain

Back 56

medulla, hypothalamus, thalamus, cerebellum; integrates subconscious activity like breathing, blood pressure, salviation, emotion and reaction to pain and pleasure

Front 57

high brain

Back 57

cerenrum or cerebral cortex (incapable of functioning without lower brain); acts to store memories and process thoughts

Front 58

sensory receptors

Back 58

transduce phsyical stimuls to neural signals

Front 59

5 types of sensory receptors

Back 59

mechanoreceptors, thermorecptors, nocicpetors, electromagnetic receptrs (for light) and chemoreceptors (tests, smell, blood chemistry)

Front 60

lens of eye

Back 60

converging lens, so flattening the eye by relaxing ciliary muscles makes it less powerful and by moving the focal point away

Front 61

cornea

Back 61

where light first strikes the eye, made mostly of collagen, refractive index of 1.4 which means most light bending accurs here

Front 62

anterior cavity

Back 62

where light enters after cornea, filled with aqueaous of himor produced by ciliariy process an dleaks out of canal of sclemm (blockage of canal -> glaucoma)

Front 63

lens

Back 63

light enters after anterior cavity; ciliarly muslces are connected which when tightend circle opening is more like a spehere and prings focal point closer; when it relaxes, more flattened and focal poitn father

Front 64

retina

Back 64

covers the inside of the back (distal portion) of the eye; contains rods and cones;

Front 65

rods

Back 65

has pigments called rhodposin; rods sense all wavelengts in the visibal espectrum; rods cannot distinguish colors

Front 66

cones

Back 66

3 types, each with different pigment that is stimulated by a slightly different spectrum of wavelenghts

Front 67

rods

Back 67

no color

Front 68

cones

Back 68

color

Front 69

fovea

Back 69

part of retina containing mostly conres, most acute vision is in fovea

Front 70

iris

Back 70

colored portion of eye that creates the opeing called pupil

Front 71

iris made of

Back 71

circular and radial muscles,

Front 72

in dark enviornment

Back 72

the eye contracts the iris, and pupils dilate allowing more light (sympathetic)

Front 73

in bright environment

Back 73

in bright environment, pupils gets smaller via parasympathetic system

Front 74

basic parts fo the ear

Back 74

outer ear, middle ear, inner ear

Front 75

cochlea

Back 75

detect sound

Front 76

semicircular canals

Back 76

detect orientation and movement of the head

Front 77

sound wave hits pinna and travels to

Back 77

tympanic membrane, which begins the middle ear

Front 78

middle ear has 3 parts

Back 78

malleus, incus and stapes, which translate the wave of sound to the oval window

Front 79

hairs cells of organs of corti

Back 79

detects movement (ie., increassing and decreasing pressure from vestibular membrane)

Front 80

simple reflex arc

Back 80

does not require neurons in the brain