Myophysiology lecture 20

Question 1

The muscle fiber contains an ion gradient that produces a resting power of ?

Answer 1

-90 millivolts (mV)

Question 2

True or false.

Sodium ion (Na+1) is high outside the cell

Answer 2

True - sodium ion is very high outside the cell but low inside

Question 3

Potassium ion (K+1) is very low inside the cell? T/F

Answer 3

False - it’s very high inside the cell

Question 4

When Opening the ligand-gated channels what flows in and pitch

Answer 4

NA+1 into the cell and K+1 outside of the cell

Question 5

What is depolarization

Answer 5

A rapid change in potential. Once the depolarization is initiated at any point in the membrane a wave of depolarization passes over the entire membrane (sarcolemma)

Question 6

What is the membrane in the muscle called?

Answer 6

Sarcolemma

Question 7

Action Potentional

What causes the depolarization?

Answer 7

Once the Sodium channels open up(Na+1) it causes depolarization becuase the sodium entered

Question 8

Muscle fiber membrane?

Answer 8

Sacromella

Question 9

All or none law

True or false - the muscle fibers are fully contexted or full relaxed

Answer 9

True

Question 10

The all all of non law applied to gross muscle

Answer 10

False -

We can control how gross muscle fiber but how many we stimulate. They pull against each other to control the rates… and control how far muscle moves limb.

Question 11

Neuromuscular Junction

Each muscle fiber had a single point of motor axon joins the fiber what is it called?

Answer 11

Neuromuscular Junction - muscle fiber is connected to a never fiber

Question 12

A nerve impose reaching the NMJ Causes the release of the neurotransmitter ____ across the gap (synapse) beteeen the nerv ending and the sacromella

Answer 12

Acetylcholine (ACH)

Question 13

Acetylcholine binds to the lighted ____ opening the channels and allowing na plus ___, deporlozjngghe membrane and intiting action potential

Answer 13

Na+ channels

Influx

Question 14

The _____ ____Acetylcholinestersae binds to the Arch in the synaps and inactive.

Answer 14

Hydrolysis enzyme

Question 15

Components necceary for muscle contraction

The mails elements of muscle contraction are :

Answer 15

Actin, myosin, the proteins of the thick and thin filaments

Question 16

T or F

ATP is needed in order to perform the process of the contraction and relaxation.

Answer 16

True

This is provided. Y the large number of mitochondria in the sarcoplans surrounding the myofibrils

Question 17

T or f

There is a false component called calcium ion (CA+2)

Answer 17

True.

Question 18

The Ca+2 is present in the sacroplasm

Answer 18

False.

It is the influx of this ion during depolarization that initiates contract

Question 19

Calcium Chanel’s

The t-rubles are invaginations of the sarcolemma . The for a raid with two Custer army that are part of the SR which contain high levels of ?

Answer 19

Ca++

Question 20

Calcium Chanel’s

With the fisher we are the end of the t rubles they are voltage ca+2 channels that open in response to the depolarization wave from the sarcolemma down the t rubles

Answer 20

True

Question 21

Calcium channels

Sa the diffuses into the sarcoplans binding to the proteins called tooo in associated wiht actin in the sarcomere which starts the process of contraction

Answer 21

True

Question 22

How many components to the thin filament

Answer 22

3 - actin, tropoin, and tropomyosion

Question 23

Thick filament molecule structure

Active binding sites

ATP binding sites

Answer 23

Long thing fiber structure and little heads . Cross bridges . Looks like a golf club.

Question 24

Energy spruce for muscle

ATP is not necessary for both contagion (myosin head cock) and relaxation

Answer 24

False

ATP is necceaery for both contraction and relaxation. The muscle fiber has several sources

Gylotic parhway - breakdown of the glucose in the present kf oxygen generates the greatest amounts

Creative phosphate - do can exchange the terminal phosphate with AdP to produce atp quickly

Fermentation- in the absence of oxygen the muscle fiber has limited ability to produce atp but also lactic acid

Question 25

Contraction

The binding of Ca+2 into the Tripp in causes it to pull the protein ____away from the acting binding site for myosin and exposing it

Answer 25

Tropomyosin

The myosin head binds to fresh atp and takes it energy to bind to the actin and flex (power stroke m)

The myosin slides a little bit over the actin filament

The presence of additional atp causes the myosin head to let go of the actin and flex back binding again to atp

The process is repeated until either ca+2 is removed atp is used up or filaments have overlapped as much as possible

Question 26

Oxygen depletion

What is the most efficient source of energy for the muscle fiber

Answer 26

Aeorobic digestion of glucose. However this requires a continues abundant source of energy