Neurophysiology Ii- The Synapse And Neurotransmitters

Front 1

What is the synapse?

Back 1

A fluid filled junction that mediates information transfer

Front 2

Where does the information from the synapse go?

Back 2

To another neuron, or an effector

Front 3

Explain the presynaptic neuron

Back 3

Conducts impulses toward the synapse

Front 4

Explain the postsynaptic neuron

Back 4

Transmits impulses away from the synapse

Front 5

Explain electrical synapse

Back 5

-Uncommon

-Neurons are electrically coupled (joined by gad junctions)

-Communication is very rapid

Front 6

Is the communication in electrical synapse's unidirectional, or bidirectional?

Back 6

They can be both

Front 7

Where is electrical synapses important?

Back 7

-Embryonic nervous tissue

-some brain regions

-Cardiac muscles

*They are gap junctions

Front 8

What is the most common synapse?

Back 8

Chemical synapse

Front 9

How does the chemical synapse work?

Back 9

-Presynaptic neuron releases neurotransmitter to postsynaptic neuron

-Neurotransmitters open or close chemically gated ion channels

-Axonal terminals of presynaptic neuron contains synaptic vesicles filled with neurotransmitters

Front 10

What is the synaptic cleft?

Back 10

Fluid-filled space separating the presynapticand postsynaptic neurons

Front 11

What does the synaptic cleft prevent?

Back 11

Prevents nerve impulses from directly passing from one neuron to the next

Front 12

Explain the transmission across the synaptic cleft?

Back 12

–Is a chemical event

–Involves release, diffusion, and binding of

neurotransmitters

–Ensures unidirectional communication between

neurons

Front 13

What do saturated fat and cholesterol do in relation to the synapse?

Back 13

Blocks receptors

Front 14

How is calcium important in the synapse?

Back 14

The diffusion of the neurotransmitters activate voltage gated calcium channels, which helps move the vesicles along the microtubles

Front 15

What are examples are things that block receptors?

Back 15

BPA, jet fuels, round up

Front 16

What are the 3 ways to terminate the neurotransmitter?

Back 16

Degradation by enzymes

Reuptake by astrocytes or presynaptic terminal

diffusion out of the synaptic cleft

Front 17

What are the 2 types of postsynaptic potentials?

(Graded potential)

Back 17

EPSP- Excitatory postsynaptic potential-Depolarization

IPSP- Inhibitory postsynaptic potentials-

Hyperpolarization

Front 18

What is temporal summation?

Back 18

one or more presynaptic neurons transmit impulses in Rapid-fire order

Front 19

What is spatial summation?

Back 19

Postsynaptic neuron is stimulated by a large number of terminals at the same time

Front 20

What part of your body contributes to 85% of your immune system?

Back 20

GI tract

Front 21

True or false:

Most neurons make two or more neurotransmitters, which are released at different stimulation frequencies?

Back 21

True

Front 22

What is acetylcholine?

Back 22

Neuromuscular neurotransmitter

Inhibitory at cardiac muscle, excitatory at skeletalmuscle and in CNS, can be either in ANS

Front 23

What are common side effects of acetylcholine?

Back 23

A neurotransmitter that slows heart rate

and excites muscle

Front 24

What is atropine?

Back 24

Blocks binding sites for acetylcholine in the ANS

Front 25

What does nicotine do?

Back 25

Mimics the effects of acetylcholine at the cns binding sites

Front 26

What does Botox do?

Back 26

Inhibits the release of acetylcholine at neurotransmitter junction

(cause paralysis)

Front 27

How can Botox be deadly?

Back 27

If it is injected into a blood vessel it will cause respiratory paralysis, and cause death

Front 28

What does pavulon (curare)?

Back 28

Blocks the binding of acetylcholine at neuromuscluar junction. **causes paralysis

Front 29

What is the name of the auto immune disease which the white blood cells attack the ach receptors?

Back 29

Myasthenia gravis

Front 30

What are common uses for atropine in the medical field?

Back 30

Given to patients with a very slow heart rate to speed it up

Helps severe diarrhea but increases heart rate

given before surgery to help with upset stomach

Front 31

What chemicals hinder actycholine?

Back 31

Atropine, nicotine, Botox, pavulon (curare)

Front 32

How does tyrosine "turn into" epinephrine?

Back 32

Tyrosine---> L-dopa---->Dopamine--->Norepinephrine---Epinephrine

Front 33

What classification of neurotransmitters is very stimulating, and derives from tyrosine?

Back 33

Catecholamines

Front 34

Is dopamine excitatory or inhibitory?

Back 34

It can be both

Front 35

Dopamine is releases in the CNS and is associated with _______?

Back 35

Positive emotions and coordination of movement (made in substantia nigra- basal nuclei)

Front 36

What does low levels of dopamine cause?

Back 36

Parkinson's disease

Front 37

What does high levels of dopamine cause?

Back 37

Schizophrenia

Front 38

What chemicals enhance the release of dopamine?

Back 38

L-dopa and amphetamines

Front 39

What drug blocks the removal/reuptake of dopamine?

(Enhances the effect of dopamine)

Back 39

Cocaine

Front 40

What is the main neurotransmitter for the ANS?

Back 40

Norepinephrine

Front 41

Is norepinephrine excitatory or inhibitory?

Back 41

Both

Front 42

What is norepinephrine associated with?

Back 42

Positive emotions

Front 43

What enhances the release of both dopamine and norepinephrine?

Back 43

Amphetamines

Front 44

What blocks the removal/reuptake of norepinephrine?

Back 44

Cocaine and older antidepressants

Front 45

What is epinephrine?

Back 45

A hormone from the adrenal glands as well as a neurotransmitter from the CNS

Front 46

What effects does epinephrine cause?

Back 46

Same effects as norepinephrine

Front 47

Where is 85% of the body's serotonin supply produced?

Back 47

In the GI tract

Front 48

What neurotransmitters are made from amino acids?

Back 48

Gaba, Glycine, aspartic acid, glutamic acid

Front 49

What neurotransmitters are made from tyrosine?

Back 49

The catecholamines-

Epinephrine,Norepinephrine, and dopamine

Front 50

What amines neurotransmitters are indolamines?

Back 50

Serotonin, and histamine

Front 51

What is serotonin made from?

Back 51

Tryptophan

Front 52

Is serotonin excitatory, or inhibitory?

Back 52

Mostly inhibitory

Front 53

What are the effects of serotonin?

Back 53

(A lot of functions in the CNS)

Sleep, appetite,mood,libido

Front 54

What happens if someone has low serotonin levels?

Back 54

This can cause migraines, depression,IBS, anxiety, OCD

Front 55

What blocks serotonin?

Back 55

LSD

Front 56

What blocks the reuptake of serotonin, which enhances its effect?

Back 56

SSRI's

Front 57

What is another use for serotonin?

Back 57

Used by neurons that inhibit pain transmission

Front 58

What is serotonin syndrome, and what are the symptoms?

Back 58

Too much serotonin, causes high heart rate, diarrhea, tremors, and can progress into a come or death

Front 59

What causes serotonin syndrome?

Back 59

Medications that increase serotonin levels

Examples-Prozac, lexapro

Front 60

What is histamine made from?

Back 60

The amino acid Histadine

Front 61

What is histamine?

Back 61

Found in the hypothalamus as a neurotransmitter

(Causes sleepiness)

Front 62

What is another way histamine is produced besides in the brain?

Back 62

Also produced by mast cells (allergy)

Causes swelling due to leaky dilated vessels

Front 63

What happens if someone gets too much histamine?

Back 63

Anxiety, heart burn, diarrhea

Front 64

Where in the body is glycine more inhibitory?

Back 64

The spinal cord

Front 65

What blocks glycine, and what does the blocking cause?

Back 65

Strychnine blocks it causing convulsion or death

Front 66

What is GABA made from?

Back 66

It id derived from, but not a true amino acid

Front 67

Where in the body is GABA inhibitory?

Back 67

The brain

Examples- Valium, lorazepam

Front 68

Where in the body is glumate excitatory? (MSG)

(Associated with memory)

Back 68

In the brain

Front 69

What results from excessive release of glumate?

Back 69

Strokes

Front 70

Name the peptides (neuropeptides)

Back 70

Substance p-(Excitatory) pain signals in PNS

Endorphins-Acts as natural opiates, reducing pain perception

Gut-Brain peptides-Somatostatin, and cholecystokinin

Front 71

What are purines?

Back 71

–Monomers of nucleic acids that have an effect in both CNS and PNS

•ATP, the energy molecule, is now considered a neurotransmitter

•Adenosine is a potent inhibitor in brain–Caffeine blocks adenosine receptors

•Can induce Ca2+ influx in astrocyte

Front 72

What are neurotranmitter modulators?

Back 72

Gases and lipids

Front 73

Explain the gasotransmitter Nitric oxide

Back 73

•Synthesized on demand

•Activates the intracellular receptor guanylyl cyclase tocyclic GMP

•Involved in learning and memory

•Responsible for relaxing smooth muscle (vessels, organs and decreases BP)» Viagra, Levitra, and Cialis (block NO breakdown)

Front 74

Explain the gasotransmitter carbon monoxide

Back 74

•Toxic gas in large quantities

•CNS only increases cyclic GMP

•Cigarettes contain CO, so quitting smoking may leave the smoker feeling “dulled” and “cloudy”

Front 75

Explain endocannabinoids

Back 75

•Lipid soluble; synthesized on demand from membrane lipids

•Bind with G protein–coupled receptors in the brain•Involved in learning and memory

•THC and CBD•CBD seems to have most active role in pain, immune,and neurological involvement

Front 76

What neurotransmitters are considered uppers?

Back 76

–Serotonin–Acetylcholine–Norepinephrine–Epinephrine–Dopamine–Glycine**

Front 77

What neurotransmitters are considered downers?

Back 77

–GABA–Nitric Oxide–Histamine–Neurosteroids–Glycine**

Front 78

What are the 3 balancing neurotransmitters?

Back 78

Serotonin –Glycine - Acetylcholine

Front 79

What are the 2 types of neurotransmitter receptors?

Back 79

Channel-linked receptors

G protein linked receptors

Front 80

Explain the channel-linked receptors

Back 80

•Ligand-gated ion channels

•Action is immediate and brief

•Excitatory receptors are channels for small cations

•Na+ influx contributes most to depolarization•Inhibitory receptors allow Cl– influx or K+ efflux that causes hyperpolarization

Front 81

Explain the G protein- linked receptors

(metabotropic)

Back 81

•Trans membrane protein complexes

•Responses are indirect, slow, complex, and often prolonged and widespread

Front 82

Define the second messengers used in G protein- linked receptors

Back 82

–Open or close ion channels

–Activate kinase enzymes

–Phosphorylate channel proteins

–Activate genes and induce protein synthesis

Front 83

Which type of synapse is the most rapid-

Chemical synapse, or electrical synapse?

Back 83

Electrical synapse

Front 84

What are myelinated sheaths in the PNS formed by?

Back 84

Schwann cells

Front 85

What are myelinated sheaths in the CNS formed by?

Back 85

oligodendrocytes

Front 86

What is the most common neuron in the CNS?

Back 86

Multipolar

Front 87

Where are unipolar neurons most commonly found?

Back 87

Found in the PNS as sensory neurons

Front 88

What kind of neurons carry impulses away from the CNS to effectors?

Back 88

Motor (efferent) neurons

Front 89

What kind of neurons lie between the motor and sensory neurons?

Back 89

Interneurons

Front 90

What constitutes the elctrochemical gradient that determines which way ions flow?

Back 90

The electrical and concentration gradient together

Front 91

________ synapses are either excitatory or inhibitory depending on hoe they affect the membrane potential of the post synaptic neuron

Back 91

Chemical