Physiology: Skeletal Muscle

Front 1

What type of neural pathway serves skeletal muscle?

Back 1

Somatic motor pathway.

Front 2

Skeletal muscle is the:

Back 2

molecular basis of muscle contraction

Front 3

Is skeletal muscle excitable?

Back 3

Yes.

Front 4

The depolarization of a muscle contraction is due to:

Back 4

the opening of voltage gated Na+ channels.

Front 5

The repolarization of a nerve in a muscle during muscle traction is due to:

Back 5

opening of voltage gated K+ channel.s

Front 6

Are muscles neurogenic or myogenic?

Back 6

Neurogenic.

Front 7

Latent period in a muscle refers to;

Back 7

the point of electrical stimulus.

Front 8

Is Skeletal muscle anerobic or aerobic?

Back 8

Aerobic.

Front 9

Sarcoplasmic reticulum is:

Back 9

like the endoplasmic reticulum, a palce where we house Ca2+ ions.

Front 10

The Sarcolima is :

Back 10

same as a cell membrane. Around a muscle cell. Voltage gated channels all alon the outside.

Front 11

A T-tubule is:

Back 11

transverse-continuous sarcolima into the depth of a cell. Continues waves of depolarization inside the cell.

Front 12

What are the tree types of proteins in a muscle fiber?

Back 12

Contractile, accessory and regulatory

Front 13

Contractile protein in a muscle fiber:

Back 13

actin and myosin

Front 14

Accessory proteins in a muscle fiber:

Back 14

titin and nebulin. The "supporting players"

Front 15

Regulatory proteins in a muscle fiber:

Back 15

tropomyasin and troponin

Front 16

Thin filaments in a muscle fiber are made of:

Back 16

Actin

Front 17

each G-actin has a _______ ____ for a ______ ____.

Back 17

binding site; myosin head

Front 18

Two F- actin:

Back 18

twist to double strand

Front 19

tropomyosin makes up the ___:

Back 19

outside of the thin filament

Front 20

The goal of each G-actin is to:

Back 20

make a cross-bridge with myosin head.

Front 21

Thick filaments are made of

Back 21

myosin

Front 22

Each myosin molecule consists of:

Back 22

a head, tail and hinge

Front 23

There are approx. _____ myosin molecules per thick filament.

Back 23

250.

Front 24

The myosin have two binding sites. They are _____ and ___.

Back 24

Actin (to make cross bridges) and ATP.

Front 25

The links in the sarcomere do this :

Back 25

overlap or slide over eachother

Front 26

The two accessory proteins are :

Back 26

Titin and nebulin

Front 27

The accessory protein Titin:

Back 27

the largest known protein. Used to stablize myosin. Provides elasticity to enable sarcmere to get longer or shorter.

Front 28

The accessory protein Nebulin:

Back 28

ISN'T elastic. Acts as a guide wire for actin. Helps align it.

Front 29

Regulatory proteins:

Back 29

The on/of proteins. Tropomyosin and Troponin.

Front 30

Tropomyosin:

Back 30

wraps around the actin filament. Partially blocks myosin-binding sites

Front 31

Troponin

Back 31

controls the position of the tropomyosin. Binds with calcium. You throw calcium on Troponin to get tropomyosin off actin.

Front 32

How do muscles contract?

Back 32

The thick and thin filaments do not change lenth but slide past one another. The distance between Z lines get smaller.

Front 33

Excitation-contraction coupling:

Back 33

the conversion ofn an electrical signal into a calcium signal.

Front 34

The entry of __ through ___ receptor channel initiates an action potential.

Back 34

Na+; Ach

Front 35

muscle twitch:

Back 35

the development of tension during contraction and relaxation

Front 36

the time period of rigor mortin

Back 36

3-12 hours after death.

Front 37

Why does rigor mortis happen?

Back 37

the absense of fresh ATP. If you don't have ATp then you can't run Ca+ ATPase pump

Front 38

What happens in rigor mortis?

Back 38

All cross bridges stay in rigor state. It's not just one muscle but with agonists and antagonists.

Front 39

Our storage of ATp only has enough for _ twitches.

Back 39

8. (this is only a couple of seconds)

Front 40

Where do muscles get the ATP to work muscle contraction?

Back 40

Phosphocreatin (the most popular form of ATP storage). Aerobic Metablism, Anaerobic metablism

Front 41

This type of respiration provides 95% ATP demands of resting cell

Back 41

aerobic respiration

Front 42

There is ______ ATP per glucose molecule in aerobic respiration.

Back 42

a lot!

Front 43

What fuels aerobic respiration?

Back 43

glucose

Front 44

what is the production rate of aerobic respiration?

Back 44

slow but steady.

Front 45

what are the advantages and disadvantages of aerobic respiration?

Back 45

It's slow and steady so you are less likely to tire and more resistant to fatigue. Disadvantage- a slow process

Front 46

What is anohter name for anerobic respiration?

Back 46

glycolysis

Front 47

huw much ATP per glucose molecule is made in anaerobic respiration?

Back 47

not much

Front 48

what is the production rate of ATP in anaerobic respiration?

Back 48

FAST

Front 49

Why does anaerboic respiration support high intensity exercise?

Back 49

Because when you exercise for a short duration you need a LOT of ATP

Front 50

What are the advantages and disadvantages of anaerobic respiration?

Back 50

Advantage=RAPID production Disadvangage=produce lactate and use up fuel extremely fast.

Front 51

What causes muscle fatigue?

Back 51

Accumulation of = lactic acid, K+, H+, Pi. Depletion of energy reserves=PCr, ATP, glycogen) or Ca from SR.

Front 52

What causes neuromuscular fatigue?

Back 52

depletion of ACh

Front 53

What is muscle fatigue?

Back 53

when you are no longer able to exert a force on a load and overcome it.

Front 54

What is oxygen debt?

Back 54

How much oxygen needed to inhale in order to make ATP.

Front 55

What are the types of skeletal muscle fibers?

Back 55

Slow-twitch oxidative fibers, fast-twitch oxidative-glycolytic fibers, fast-twitch glycolytic fibers.

Front 56

How do you classify a muscle on the speed of it's contraction?

Back 56

1. isoform of myosin ATPase 2. Rate of SR removal of Ca out of cytoplasm

Front 57

How do you classify a muscle on resistance to fatigue?

Back 57

1. Waste product accumulation 2. efficiency in receiving oxygen.

Front 58

Slow twitch muscle gets ______ faster.

Back 58

Oxygen

Front 59

What is summation?

Back 59

the degree of contraction of a skeletal muscle is influenced by the number of motor units being stimulated

Front 60

A muscle twitch is faster/slower than an action potential.

Back 60

slower

Front 61

The refractory period of a muscle...

Back 61

limits the rate of action potentials

Front 62

What is muscle tetanus?

Back 62

Prolonged contraction of muscle fibers.

Front 63

What does a motor unit consist of?

Back 63

a single motor neuron and the muscle fibers it inervates

Front 64

The greater the number of fibers contracting, the greater the _______ produced.

Back 64

tension