Musculoskeletal Skeletal Muscle And More!?!

Front 1

What is the term for voluntarily slowing your heart rate?

Back 1

Vagal Toning

Front 2

What kind on synapses do you have in smooth and skeletal muscle?

Back 2

Chemical synapses

Front 3

What kind of synapse do you have in cardiac muscle?

Back 3

Electrical

Front 4

What kind of receptor does ACh bind to on muscle motor endplates?

Back 4

Nicotinic receptors

Front 5

What creates the end-plate potential (EPP)?

Back 5

Net influx of Na+ through ligand gated channels depolarizes the muscle membrane (step 4)

Front 6

What is the 1st step in converting an electrical signal to a mechanical response?

Back 6

Action potential of somatic motoneuron reaches nerve terminus

Front 7

What is the 2nd step in converting an electrical signal to a mechanical response?

Back 7

Voltage gated Ca++ channels on the nerve open. Ca++ entry into the nerve endings triggers exocytosis of ACh containing vesicles

Front 8

What is the 3rd step in converting an electrical signal to a mechanical response?

Back 8

Acetylcholine diffuses into synaptic cleft and binds to nicotinic channel receptors on muscle motor endplate.

Front 9

What is the 4th step in converting an electrical signal to a mechanical response?

Back 9

Net influx of Na+ through the acetylcholine (ligand) gated channels depolarizes the muscle membrane, creating an end-plate potential (EPP). In normal situations, the EPP always creates a muscle action potential.

Front 10

What is the 5th step in converting an electrical signal to a mechanical response?

Back 10

The action potential spreads from the neuromuscular junction along the fiber membrane and through the t-tubules.

Front 11

Where is the terminal cistern located?

Back 11

On either side of a T-tubule. Between a T-tubule and the sarcoplasmic reticulum.

Front 12

What does the sarcoplasmic reticulum contain?

Back 12

Things like Ca++

Front 13

What is the 6th step in converting an electrical signal to a mechanical response?

Back 13

Voltage sensitive DHP receptors in the T-tubule allow Ca++ to enter the cell into the terminal cistern area.

Front 14

What type of calcium channel are DHP receptors?

Back 14

DHP receptors are a type of L-type calcium channel

Front 15

What causes ryanodine channels on the sarcoplasmic reticulum to open?

Back 15

The increase in intracellular calcium causes ryanodine channels to open

Front 16

What is one T-tubule and two cisterns?

Back 16

A Triad

Front 17

What is the purpose of T-tubules?

Back 17

To disseminate the energy down into a muscle cell

Front 18

In skeletal muscle, what directly activates the release of Ca++ from the Sarcoplasmic reticulum?

Back 18

VDCCs (voltage-dependent calcium channels)

Front 19

What signaling molecule triggers muscle contraction?

Back 19

Ca++

Front 20

What is in the sarcoplasmic reticulum that transports Ca++ back into the lumen, decreasing the cytoplasmic Ca++ concentration, and the muscle relaxes?

Back 20

Ca++-ATPase in the sarcoplasmic reticulum

Front 21

What types of muscle use VDCCs to allow entry of Ca++?

Back 21

Skeletal and Cardiac Muscle

Front 22

What is a calcium channel blocker used for treatment of hypertension?

Back 22

DHP = dihydropyridine, nifedipine

Front 23

What allows myosin to release inorganic phosphate from ATP hydrolysis and complete the power stroke?

Back 23

Ca++ binding to troponin, pulling tropomyosin off the myosin binding site of actin

Front 24

What happens at the end of a power stroke under normal circumstances?

Back 24

The myosin cross bridges release ADP and remain tightly bound to actin until ATP binds the myosin head and releases it from the binding site.

Front 25

What makes myosin heads lock in a state of rigor?

Back 25

No ATP to release the head

Front 26

When does the muscle fiber relax? (chemically)

Back 26

When Ca++ is transported back into the sarcoplasmic reticulum

Front 27

What causes hydrolysis of ATP in the cross-bridge cycle?

Back 27

The myosin head acts as an ATPase

Front 28

What is a ball at the end of the nerve ending. Inside of which are synaptic vesicles created within the neuron?

Back 28

Presynaptic Bouton (nerve terminus)

Front 29

What contains the neurotransmitters and can have 100s or 1000s in a bouton?

Back 29

Synaptic Vesicles

Front 30

What determines how much time it will take from the release of a neurotransmitter to stimulate the contraction of the muscle?

Back 30

The distance of the Synaptic Cleft

Front 31

What is a type of SNARE protein, involved in the fusion of membranes in the exocytosis of vesicles?

Back 31

Synaptobrevin

Front 32

What protein regulates the number of synaptic vesicles available for exocytosis?

Back 32

Synapsin

Front 33

What is the amount of neurotransmitter contained in one synaptic vesicle?

Back 33

Quantum

Front 34

What does the amount of neurotransmitter released depend upon?

Back 34

The number of vesicles that fuse with the presynaptic membrane in response to Ca++ influx

Front 35

T/F The motor end plate is a receptor region -- it contains lots of receptors specific for a particular neurotransmitter.

Back 35

True

Front 36

what does a Ligand Gated Sodium Channel activate?

Back 36

ACh binds and Na+ enters the cell

Front 37

T/F
Ligand gated sodium channel receptors has 2 binding sites for ACh but only one need to be bound to ACh for the response to occur.

Back 37

False
Both need to be bound to occur

Front 38

What happens as more and more ligand gated sodium channel receptors bind to ACh?

Back 38

The muscle stimulation gets bigger and bigger

Front 39

What is the change in membrane potential induced by the action of multiple mini end plate potentials called?

Back 39

The End Plate Potential

Front 40

What molecule is primarily involved in the depolarization of the myocyte?

Back 40

Na+

Front 41

What molecule is more significant than Na+ at the synaptic cleft?

Back 41

Ca++

Front 42

What molecule sets off a cascade which causes the NT vesicles inside the motor neuron to migrate to the synaptic cleft and release ACh?

Back 42

Ca++

Front 43

What molecule is released based upon the quantum of energy that comes from the bouton?

Back 43

Ca++

Front 44

What is the primary NT substance released by motor neurons to stimulate a skeletal muscle contraction?

Back 44

ACh

Front 45

What is bound to the motor end plate region and helps to degrade ACh and allows for its resorption back into the bouton?

Back 45

Acetylcholineesterase
(ACh-Esterase)

Front 46

What toxin is found in blow fish and blocks Na+ channels on BOTH the nerve process and the muscle cell?

Back 46

Tetrodotoxin

Front 47

What blocks ACh release into the synaptic cleft by dissolving SNARE proteins in the motor neuron?

Back 47

Tetanus and Botulinus Toxin

Front 48

What are Reversible cholinesterase inhibitors?

Back 48

Physostigmine & Neostigmine

Front 49

What are Irreversible cholinesterase inhibitors found in fertilizers?

Back 49

Organophosphate

Front 50

What facillitates binding of ACh at the motor end plate?

Back 50

Nicotine and ACh

Front 51

What are Fast Acting competative inhibitors competing for ACh receptors?

Back 51

Alpha-bungarotoxin (Cobra Venom)

Front 52

What are Slow Acting competative inhibitors competing for ACh receptors, used in surgery for temporary relaxation of muscles?

Back 52

Turbocurrarine (curare)

Front 53

What blocks potassium channels, preventing repolarization? (has the same effect as a cholinesterase inhibitor)

Back 53

Dendrotoxin (mamba venom)

Front 54

What type of receptor has:
Ligand gated ion channel
Open or close in response to a chemical stimulus
Nicotinic Receptor

Back 54

Ionotropic Receptor

Front 55

What type of receptor:
Do not form an ion channel pore
Instead, are indirectly linked with ion-channels on the plasma membrane of the cell through signal transduction mechanisms
When the NT is released and attaches to the metabotropic receptor, it initiates a G-protein cascade
Muscarinic Receptor

Back 55

Metabotropic Receptor

Front 56

Where is Troponin T?

Back 56

Attached to tropomyosin

Front 57

Where is Troponin I?

Back 57

Attached to actin

Front 58

Where is Troponin C?

Back 58

Troponin C is the Ca++ binding site

Front 59

When Troponin I is attached to actin what happens?

Back 59

It is Inactive (get it...I, oh the irony of nomenclature)

Front 60

T/F
The myosin has a tail and a hinge as well as multiple heads. On the head, there is an alkali component that helps stabilize it. There is also a regulatory component that regulates ATPase.

Back 60

True