Pa Anatomy Term Quiz 3

Front 1

leak ion channel

Back 1

channels that randomly open and close to let ions in or out

Front 2

ligand-gated channel

Back 2

channel that opens in response to a ligand binding to it

Front 3

voltage-gated channel

Back 3

channel that opens in response to a change in membrane potential

Front 4

graded potential

Back 4

a small deviation from the resting membrane potential that makes the membrane more or less polarized

Front 5

hyperpolarizing

Back 5

resting membrane potential becomes more negative

Front 6

depolarizing

Back 6

resting membrane potential becomes less negative

Front 7

summation

Back 7

the process by which graded potentials add together

Front 8

threshold

Back 8

when depolarization reaches a certain level, it fires an action potential

Front 9

all-or-none pricipal

Back 9

action potential either fires or does not, there is no in between

Front 10

refractory period

Back 10

the time a cell can't fire another action potential even if threshold is reached

Front 11

local anesthetics

Back 11

drugs that block pain, block the opening of voltage-gated Na+ channels

Front 12

saltatory conduction

Back 12

occurs in myelinated axons, special mode of action potential propogation

Front 13

presynaptic neuron

Back 13

nerve cell that carries a nerve impulse towards a synapse

Front 14

postsynaptic neuron

Back 14

carries a nerve impulse away from a synapse

Front 15

synaptic cleft

Back 15

space between presynaptic and postsynaptic neurons that's filled with interstitial fluid

Front 16

postsynaptic potential

Back 16

graded potential, converts electrical signal into a chemical signal

Front 17

EPSP

Back 17

a neurotransmitter that causes depolarization of the postsynaptic membrane, brings closer to threshold

Front 18

IPSP

Back 18

a neurotransmitter that causes the hyperpolarization of the postsynaptic membrane

Front 19

spatial summation

Back 19

summation of post-synaptic potentials in response to stimuli released at different locations at the same time

Front 20

temporal summation

Back 20

summation that occurs at different times

Front 21

acetycholine

Back 21

an excitatory and inhibitory neurotransmitter, a small molecule

Front 22

GABA

Back 22

inhibitory neurotransmitter, amino acid, small group

Front 23

catecholamines

Back 23

dopamine/epinephrine, have amino group and a catechol ring

Front 24

nitric oxide

Back 24

NO, excitatory, gas, secreted in brain, spinal cord, adrenal glands, and penis nerves

Front 25

agonist

Back 25

an agent that binds to receptors and enhances or mimics the effect of a natural neurotransmitter

Front 26

antagonist

Back 26

an agent that binds to and blocks neurotransmitter receptors

Front 27

neural divergence

Back 27

one presynaptic neuron influences several postsynaptic neurons

Front 28

neural convergence

Back 28

several presynaptic neurons synapse with a single postsynaptic neuron

Front 29

plasticity

Back 29

the capability to change based on experience

Front 30

excitotoxicity

Back 30

destruction of neurons through prolonged activation of excitatory synaptic transmission

Front 31

SSRIs

Back 31

drugs that provide relief from some forms of depression

Front 32

spinal tap

Back 32

procedure to get CSF out of the spinal cord, to test/diagnose or introduce medicine

Front 33

posterior root

Back 33

only sensory axons, conduct nerve impulses from receptors in the skin into CNS

Front 34

anterior root

Back 34

contains axons of motor neurons, conduct nerve impulses away from the CNS to effectors

Front 35

posterior gray horns

Back 35

cell bodies and axons of interneurons as well as axons of incoming sensory neurons

Front 36

anterior gray horns

Back 36

contain somatic motor nuclei, provide nerve impulses for contraction of skeletal muscle

Front 37

lateral gray horns

Back 37

present only in thoracic and upper lumbar, regulate cardiac, smooth, and glands

Front 38

sensory tracts

Back 38

axons that conduct nerve impulses toward the brain

Front 39

motor tracts

Back 39

axons that carry nerve impulses away from the brain

Front 40

mixed nerve

Back 40

a nerve that has motor and sensory tracts

Front 41

posterior ramus

Back 41

serves the deep muscles and skin of the posterior surface of the trunk

Front 42

anterior ramus

Back 42

serves the muscles and structures of the upper and lower limbs and the skin of the lateral and anterior surfaces of the trunk

Front 43

plexus

Back 43

axons that do not go directly to the body structures they supply, instead form networks

Front 44

intercostal nerves

Back 44

anterior rami of spinal nerves that do not enter into the formation of plexuses

Front 45

dermatome

Back 45

the area of the skin that provides sensory input to the CNS via one pair of spinal nerves or the trigeminal

Front 46

direct motor pathways

Back 46

convey nerve impulses that originate in the cerebral cortex and become voluntary movements

Front 47

indirect motor pathways

Back 47

convey nerve impulses from the brain stem to cause automatic movements and help coordinate body movements with visual stimuli

Front 48

somatic reflexes

Back 48

involve contraction of skeletal muscles,

Front 49

autonomic reflexes

Back 49

generally not consciously percieved, responses of smooth, cardiac, and glands

Front 50

integrating center

Back 50

a single synapse between a sensory neuron and a motor neuron

Front 51

muscle tone

Back 51

the small degree of contraction present while the muscle is at rest

Front 52

tendon reflex

Back 52

a feedback mechanism to control muscle tension by causing muscle relaxation before muscle force makes tendons tear

Front 53

contralateral

Back 53

sensory impulses enter one side of the spinal cord and motor impulses exit on the opposite side

Front 54

paraplegia

Back 54

paralysis of both lower limbs

Front 55

hemiplegia

Back 55

paralysis of the upper limb, trunk, and lower lib on one side of the body

Front 56

quadriplegia

Back 56

paralysis of all four limbs

Front 57

hemisection

Back 57

a partial transection of the cord on either the right or the left side

Front 58

myelitis

Back 58

inflammation of the spinal cord

Front 59

neuralgia

Back 59

attacks of pain along the entire course or a branch of a sensory nerve

Front 60

paresthesia

Back 60

an abnormal sensation such as burning, prickling, tickling, or tingling resulting from a disorder of a sensory nerve

Front 61

brain stem

Back 61

continuous with the spinal cord and consists of the medulla oblongata, pons, and midbrain

Front 62

diencephalon

Back 62

superior to the brain stem, consists of the thalamus, hypothalamus, and epithalamus

Front 63

brain ventricles

Back 63

four CSF-filled cavities within the brain

Front 64

choroid plexuses

Back 64

networks of blood capillaries in the walls of the ventricles

Front 65

interventricular foramina

Back 65

CSF flows into the third ventricle through two narrow, oval openings called

Front 66

hydrocephalus

Back 66

caused by elevated CSF pressure, can cause nerve damage

Front 67

arachnoid villi

Back 67

fingerlike extensions of the arachnoid mater that project into the dural venous sinuses