Muscles

Question 1

What are the 3 types of muscle?

Answer 1

Skeletal
Cardiac
Smooth

Question 2

What types of muscles are striated?

Answer 2

Cardiac

Skeletal

Question 3

What type of muscle surrounds blood vessels, airways ect?

Answer 3

Smooth muscle

Question 4

Why do the nuclei of skeletal muscle bulge?

Answer 4

Because the muscles are so jam packed with protein

Question 5

Describe the nucleus in skeletal muscle?

Answer 5

Multinucleate

Question 6

Does muscle eve completely recover after damage?

Answer 6

No

Question 7

How are muscles attached to bones?

Answer 7

By tendons

Question 8

What type of cells differentiate to form new muscle fibres?

Answer 8

Satellite cells

Question 9

Are muscle fibres highly vascularated?

Answer 9

Yes

Question 10

What is the sarcomere composed of?

Answer 10

Thick and thin filaments

Question 11

What are the tick filaments?

Answer 11

Myosin

Question 12

What are the tin filaments?

Answer 12

Actin

Question 13

What causes the cross bridge to bind to actin?

Answer 13

A rise in Ca2+

Question 14

What partially covers myosin?

Answer 14

Tropomyosin

Question 15

What holds tropomyosin in blocking position?

Answer 15

Troponin

Question 16

What does the Ca2+ bind to?

Answer 16

Troponin

Question 17

What is the effect of calcium binding to troponin?

Answer 17

Pulls the tropomyosin away

Allowing myosin binding sites to be exposed

Question 18

What is a motor unit composed of?

Answer 18

Motor neurons + muscle fibres

Question 19

What is the force exerted by the muscle called?

Answer 19

Tension

Question 20

What is the force exerted on the muscle called?

Answer 20

Load

Question 21

What is a contraction with constant length called?

Answer 21

Isometric

Question 22

What is a contraction with shortening length called?

Answer 22

Isotonic

Question 23

What is a contraction with increasing length called?

Answer 23

Lengthening

Question 24

What are the striations caused by?

Answer 24

The sarcomeres

Question 25

As the load increases on a muscle what happens

Answer 25

More motor units are required to compensate

Question 26

What is tetanus in muscles?

Answer 26

A state of extended contraction via the summation of AP

Question 27

Why is tetanic tension much greater than twitch tension?

Answer 27

Because there is no respite in which the Ca2+ can return to the sacroplasmic reticulum

Question 28

What is muscle fatigue caused by?

Answer 28

Repeated muscle stimulation

Question 29

What are the 2 anataonist groups required in muscles?

Answer 29

The flexors | The extensors

Question 30

What does muscle fatigue prevent?

Answer 30

Muscles using up vast amounts of ATP which would cause rigor

Question 31

Why is myosin an ATPase?

Answer 31

As it hydrolyses ATP

Question 32

What is the contraction time?

Answer 32

The time between the start of tension and the time when there is peak tension

Question 33

Do al muscle fibres have the same contraction time?

Answer 33

No

Question 34

Why is tetanic tension greater than twitch tension?

Answer 34

As Ca2+ never gets low enough to allow tropomyosin to re-block myosin binding sites

Question 35

If there is too much overlap of filaments what happens

Answer 35

Filaments interfere with each other

Question 36

If there is less overlap of filaments what happens?

Answer 36

There is less tension

Question 37

What do ATP power in muscle?

Answer 37

It energises to cause binding to X bridges | Also powers Ca2+ return to SR

Question 38

What does repeated muscle stimulation cause?

Answer 38

Muscle fatigue

Question 39

How does fatigue affect K+?

Answer 39

There is conduction failure of K+ as ATP cant maintain conc. gradient

Question 40

How does muscle fatigue affect cross bridges?

Answer 40

ADP + Pi delay myosin detachment from actin filaments

Question 41

Can muscle fatigue be overcome and when?

Answer 41

Yes | Fight or flight

Question 42

In fast muscle fibres what is the ATPase activity like?

Answer 42

High

Question 43

In slow muscle fibres what is the ATPase activity like?

Answer 43

Low

Question 44

Does smooth muscle have striations?

Answer 44

No

Question 45

What is smooth muscle innrvated by?

Answer 45

The ANS

Question 46

Are smooth muscle multi or mono nucleate?

Answer 46

Mono

Question 47

How are filaments of smooth muscle arranged?

Answer 47

Diagonally

Question 48

Is there more SR in smooth or skeletal muscle?

Answer 48

Skeletal

Question 49

In smooth muscle where does the Ca2+ bind?

Answer 49

Calmodulin

Question 50

What does calmodulin bind to?

Answer 50

Myosin light chain kinase

Question 51

What does the myosin light chain kinase do?

Answer 51

Phosphorylate myosin with ATP forms cross bridges | Results in contraction

Question 52

Why is contraction held longer in smooth muscle?

Answer 52

Due to the low rate of consumption of ATP

Question 53

What is the relaxation of smooth muscle brought about by?

Answer 53

The action of myosin light chain phosphatase

Question 54

What do oxidative fibres have lots of?

Answer 54

Mitochondria

Question 55

What do oxidative fibres contain that aids O2 delivery?

Answer 55

Myoglobin

Question 56

What do glycolytic fibres have few of?

Answer 56

Mitochondria