2 - Neuronal Synapses

Question 1

___ = where a neuron transfers information to 1 or more other neurons or a muscle

Answer 1

synapse

Question 2

3 parts of the synapse?

Answer 2

1. presynaptic terminal
2. synaptic cleft
3. postsynaptic terminal

Question 3

which neuron conducts impulses toward the synapse?

Answer 3

presynaptic

Question 4

which neuron conducts impulses away from the synapse?

Answer 4

postsynaptic

Question 5

If synapse is neuromuscular, ___ or ____, the ions flowing through ligand-gated channels cause local membrane potentials.

Answer 5

axosomatic, axodentric

Question 6

if synapse is ____, presynaptic effects occur

Answer 6

axoaxonic

Question 7

Steps of synaptic transmission:
1. action potential comes to the ____ terminal

Answer 7

presynaptic

Question 8

Steps of synaptic transmission:
1. action potential comes to the presynaptic terminal
2. presynaptic terminal membrane depolarizes which opens the voltage-gated ____ channels

Answer 8

Ca+

Question 9

Steps of synaptic transmission:
1. action potential comes to the presynaptic terminal
2. presynaptic terminal membrane depolarizes which opens the voltage-gated Ca2+ channels
3. Ca2+ flows in and frees Ca2+ stored inside the cell - vesicles containing ____ are triggered to move toward release site on presynaptic membrane

Answer 9

neurotransmitters

Question 10

Steps of synaptic transmission
1. action potential comes to the presynaptic terminal
2. presynaptic terminal membrane depolarizes which opens the voltage-gated Ca2+ channels
3. Ca2+ flows in and frees Ca2+ stored inside the cell - vesicles containing neurotransmitters are triggered to move toward release site on presynaptic membrane
4. vesicles fuse with presynaptic membrane and release neurotransmitters into ___ ___
5. neurotransmitter spreads across cleft
6. neurotransmitter that touches matching ___ ___ then binds to it
7. postsynaptic receptor alters its ___ and opens associated ___ ___ or triggers associated ___ ___

Answer 10

synaptic cleft
postsynaptic receptor
ion channel
intracellular messengers

Question 11

each neuron can have different ___ of inputs in each region

Answer 11

numbers

Question 12

Strong excitatory stimuli in presynaptic neuron leads to ____ APs

Answer 12

more! - does NOT make APs stronger, just makes more

Question 13

Does the total number of AP’s that reach the presynaptic terminal directly relate to amount of neurotransmitter released?

Answer 13

yes!

Question 14

When stimulation duration is longer in presynaptic cell, the series of AP’s is ____

Answer 14

longer

Question 15

__ __: local changes in ion concentrations across the postsynaptic membrane

Answer 15

postsynaptic potentials

Question 16

____ postsynaptic potential:
- local depolarization occurs with flow of Na+ and Ca2+ into neuron
- summation facilitates AP generation
- common throughout CNS and PNS

Answer 16

excitatory

Question 17

Excitatory postsynaptic potential:
- local depolarization occurs with flow of ___ or ___ into neuron
- summation of EPSP’s facilitates AP generation
- common throughout ___ and ____

Answer 17

Na+, Ca2+
CNS, PNS

Question 18

____ postsynaptic potential:
- local hyperpolarization occurs with influx of Cl- into or K+ out of the neuron
- summation with EPSPs determines if AP is generated or not

Answer 18

Inhibitory

Question 19

Inhibitory postsynaptic potential:
- local hyperpolarization occurs influx of ___ into or ___ out of neuron
- summation with EPSPs determines if AP is generated or not

Answer 19

Cl-, K+

Question 20

___:
- 1st presynaptic neuron releases neurotransmitters that causes slight local depolarization of 2nd neuron’s presynaptic terminal
- when AP’s arrive, AP duration increases allowing more Ca2+ influx and vesicles of neurotransmitter to move and be released

Answer 20

facilitation

Question 21

Facilitation:
- 1st presynaptic neuron releases neurotransmitters that causes slight local ____ of 2nd neurons presynaptic terminal
- when APs arrive, AP duration increases allowing more ___ influx and vesicles of neurotransmitter to move and be released

Answer 21

depolarization
Ca2+

Question 22

___:
- 1st causes slight local hyperpolarization
- When APs arrive, AP duration decreases allowing less Ca2+ influx and less neurotransmitter release

Answer 22

inhibition

Question 23

Inhibition:
- 1st causes slight local ____
- when APs arrive, AP duration decreases allowing less ____ influx and less neurotransmitter release

Answer 23

hyperpolarization
Ca2+

Question 24

2 types of neuromessengers?

Answer 24

neurotransmitters, neuromodulators

Question 25

are neuromessengers facilitative, inhibitory or could be both?

Answer 25

both

Question 26

Neurotransmitters location of action?

Answer 26

synapse

Question 27

neuromodulators location of action?

Answer 27

extracellular space

Question 28

neurotransmitters method of action?

Answer 28

EPSP or IPSP

Question 29

neuromodulators method of action?

Answer 29

alter gene expression, open ion channels, change metabolism, affects many neurons

Question 30

neurotransmitters time?

Answer 30

ms to mins

Question 31

neuromodulators time?

Answer 31

mins to days

Question 32

The same chemical can function as a neurotransmitter or neuromodulator. the effect depends on what 2 things?

Answer 32

- depends if released at specific synapses or into extracellular space - depends on what part of nervous system it is released

Question 33

Is the effect of a neurotransmitter related to the receptor it binds to or the chemical it is?

Answer 33

receptor

Question 34

ligand gated ion channels are also called ___ receptor

Answer 34

ionotropic

Question 35

G protein triggering of ion chennels is also called ____ receptor

Answer 35

metabotropic

Question 36

are ligand-gated ion channels fast or slow? G protein triggering of ion channels?

Answer 36

ligand = fast G protein = slow

Question 37

G Protein 2nd messenger system: ____ is 1st messenger and ___ produced inside neuron is 2nd messenger.

Answer 37

neuromodulator, chemical

Question 38

G protein 2nd messenger system cascade of events: 1. cell produces neurotransmitters or other cellular products due to activation of ___. 2. opens ion channels 3. releases ___ to regulate metabolism and other processes

Answer 38

genes, Ca2+

Question 39

___: drugs that bind to receptors and copy actions of neurotranmitter

Answer 39

agonists

Question 40

___: drugs that block binding of neurotransmitters to receptors, drugs that inhibit release of neurotransmitters in presynaptic neurons

Answer 40

antagonists

Question 41

Acetylcholine is produced in __ ___ and ____

Answer 41

basal forebrain, midbrain

Question 42

3 places of acetylcholines effect?

Answer 42

1. skeletal muscles 2. autonomic nervous system 3. brain

Question 43

Acetylcholine effects on skeletal muscles: - ALL skeletal muscles use Ach to elicit ___-acting effects on muscle membranes -it is ___ neurotransmitter found in neuromuscular junctions to promote muscle contractions - blocking Ach receptors causes weakness, fatigue, or paralysis - what disease destroys Ach receptors?

Answer 43

fast, excitatory, myasthenia gravis

Question 44

Ach effect on autonomic nervous system: - ___ HR - __ pupils - ____ smooth muscle contractions and digestive processes

Answer 44

slows, constricts, increases so works with parasympathetic ns

Question 45

Ach effect on brain: - arousal, pleasure, cognitive function - acts as __ neuromodulator in control of movement and attention - impicated in ___ addiction and ___ disease

Answer 45

slow, nicotine, alzheimers

Question 46

___: principal fast excitatory neurotransmitter of CNS

Answer 46

glutamate

Question 47

___: neurotransmitter in virtually every brain region, neural changes with learning and development (neuroplasticity)

Answer 47

glutamate

Question 48

what are some diseases associated with glutamate?

Answer 48

changes in transmission implicated in chronic pain, parkinsons, schizophrenia, and neuron death in acute stroke

Question 49

what could happen with excessive levels of glutamate?

Answer 49

excitotoxicity and neuron death, epileptic seizures

Question 50

___: inhibits postsynaptic membranes mostly in brainstem and spinal cord

Answer 50

glycine

Question 51

___: primary inhibitory neurotransmitter in CNS, especially with interneurons in spinal cord

Answer 51

GABA

Question 52

which two neurotransmitters? - prevent excessive neural activity - low levels implicated in seizure, unwanted or involuntary muscle contractions or anxiety - alcohol, barbiturates, benzodiazepines, anticonvulsants and baclofan mimic GABA - huntingtons disease causes loss of neurons in striatum that use it with jerky involuntary movements and cognitive decline

Answer 52

Glycine and GABA

Question 53

where is dopamine produced in the brain?

Answer 53

substantia nigra

Question 54

___: affects motor function, cognition and behavior - associated with reward seeking behaviors - can be good for eating - can be bad leading to addiction

Answer 54

dopamine

Question 55

all dopamine receptors are ___ messenger systems

Answer 55

2nd

Question 56

dopamine abnormalities seen in: - ___ ___: not enough dopamine produced with bradykinesia and other symptoms presnent - precursors to dopamine given medically - ___ or ____: signaling pathways - drugs that prevent binding to receptors to alter thinking also impact motor function - excessive dopamine levels seen in cocaine or amphetamine abuse by preventing reuptake by presynatic terminals

Answer 56

parkinsons disease, schizophrenia or psychoses

Question 57

___: involved with mood, pain perception, arousal, motor activity

Answer 57

serotonin

Question 58

serotonin levels are ___ when alert and ___ during REM sleep

Answer 58

highest, lowest

Question 59

2 different types of receptors for seratonin?

Answer 59

2nd messenger systems, ligand-gated

Question 60

drugs for ___ may selectively block serotonin receptors to keep serotonin available

Answer 60

depression

Question 61

___ ___: - endogenous examples include endorphins, enkephalins and dynorphins - produced within nervous system and bind same receptors as opium - receptors found mostly in spinal cord, hypothalamus and areas in brainstem to inhibit perception of pain

Answer 61

opioid peptides

Question 62

___: produced in brainstem, hypothalamus, and thalamus

Answer 62

norepinephrine

Question 63

___: - released by neurons of ANS and secreted by adrenal glands - responsible for vigilance and "fight or flight"

Answer 63

norepinephrine

Question 64

___ __: with tissue injury, it stimulate nerve endings at injury site

Answer 64

substance P