Module 4: Lecture 1

Question 1

Structure dictates what?

Answer 1

Function

Question 2

What does “Excitation Contraction Coupling” mean?

Answer 2

we excite the muscle
and it is couples with contraction

Question 3

What is the largest group of tissues in our body?

Answer 3

muscles

Question 4

What percentage of our body mass is muscle?

Answer 4

50% with 35-40% being skeletal

Question 5

When muscles develop tension and shorten what does that create?

Answer 5

muscle contractions

Question 6

We have 2 structure classifications of muscles which are?

Answer 6

1. Striated muscle
2. Unstriated muscle

Question 7

What are the 2 subtypes of striated muscle?

Answer 7

1. Skeletal muscle
2. Cardiac muscle

Question 8

Is Skeletal muscle voluntary or involuntary?

Answer 8

voluntary

ie. bicep curl

Question 9

Is Cardiac muscle voluntary or involuntary?

Answer 9

involuntary

ie. heart beats

Question 10

Is Smooth muscle voluntary or involuntary?

Answer 10

involuntary

Question 11

Muscle are 4 sub-functions of the muscle?

Answer 11

• protecting out internal organs
• warmth (through shivering if we get to cold)
• contains/stores many amino acids
• huge component to our metabolic rate

Question 12

What is muscles main function?

Answer 12

contraction

Question 13

One single skeletal muscle cell is also referred to as what?

Answer 13

myofibre

Question 14

What are myoblasts?

Answer 14

• mono nucleotide aka one nucleus
• undifferentiated cell

Question 15

How do we get the multinucleated cell?

Answer 15

lot’s of myoblasts fuse together to create a myofibre

• the myoblasts keep their nuclei

Question 16

In adults what is the range diameter and length of myofibres?

Answer 16

• 20-100 microns in diameter
• up to 20 cm length

*vary greatly depending on body type

Question 17

What is the purpose of intercalated discs in regards to cardiac muscle?

Answer 17

• binds cell together
• allows cells to communicate with each other

Question 18

What are the Macro-organization tiers of a “generic” muscle?

Answer 18

1. Muscle
   (epimysium wraps around it)
2. Fascicle (bundle of muscle fibres, surrounded by perimysium)
3. Muscle Fibre
   (surrounded by endomysium)
4. Myofibril
   (where all our contractile proteins reside)

Question 19

What is the epimysium?

Answer 19

it is a layer of connective tissue that binds the entire muscle together

• it will continue on into the tendon sheath
• very dense and irregular

Question 20

What is the perimysium layer?

Answer 20

it is a layer of connective tissue that binds groups of fibres/cells

• it will continue on into the tendon sheath
• very dense and irregular

Question 21

What is the endomysium layer?

Answer 21

it is a layer of connective tissue that binds individual fibres/cells

• it will continue on into the tendon sheath
• very dense and irregular

Question 22

What is muscular dystrophy?

Answer 22

where you have a degradation of certain structural proteins that are responsible for some connective tissues, which will affect the mobility and the health of your skeletal muscles

Question 23

What gives muscles striations?

Answer 23

• Dark A band
• Light I band

*is where our thick and thin filaments stay

Question 24

Actin is which filaments?

Answer 24

thin

Question 25

Myosin is which filament?

Answer 25

thick

Question 26

What is a sarcomere?

Answer 26

repeating pattern along the length of the myofibril - Dark and Light band

Question 27

Within the "I" band theres these little straight lines, which are known as what?

Answer 27

Z-lines/ Z discs - represents what a sarcomeres

Question 28

What is the smallest unit of muscle that can contract?

Answer 28

sarcomeres

Question 29

Where are your myosin molecules located?

Answer 29

thick filaments

Question 30

What are your thick filaments called?

Answer 30

A band - an isotropic bond

Question 31

What does A band mean?

Answer 31

scatters light, meaning when you pass light through it the light scattered and it looks darker to us

Question 32

What does I band mean?

Answer 32

it allows light to pass through it isotropically, making it appear brighter

Question 33

What is the Z line?

Answer 33

network of connective tissue proteins, structural proteins

Question 34

What anchors a single sarcomere on either side?

Answer 34

Z line

Question 35

True or False One sarcomere is between two Z lines

Answer 35

true

Question 36

What are your thin filaments called?

Answer 36

I band

Question 37

What is the H zone?

Answer 37

center of band A where without any thin filament overlapping the thick ones

Question 38

What does the H band hold?

Answer 38

contractile proteins

Question 39

True or False The thin filaments are anchored directly to the Z-line

Answer 39

True

Question 40

True or False The thick filaments are anchored at the M line and the Z line via Titin

Answer 40

True

Question 41

What is the M-line?

Answer 41

center of the thick filament

Question 42

What is the largest SINGLE protein in the body?

Answer 42

Titin

Question 43

What anchors the Thick filaments to the Z-line?

Answer 43

Titin

Question 44

What are the Thick filaments made of?

Answer 44

- Myosin head - Myosin tail

Question 45

What are thin filaments made of?

Answer 45

- Majority actin Regulatory proteins: - troponin - tropomyosin

Question 46

Why is troponin and tropomyosin important?

Answer 46

key for muscle contractions

Question 47

What is a cross bridge?

Answer 47

- responsible for force generation - where the myosin molecules extend to reach the thin action filaments for muscle contraction

Question 48

What is the sliding movement?

Answer 48

where our thick and thin filaments move towards the center of the sarcomere for muscle shortening and muscle tension

Question 49

For any given thick filament how many actin molecules (think filaments) will be surrounding it?

Answer 49

6 in a hexagonal pattern

Question 50

For any given thin filament how many molecules (think filaments) will be surrounding it?

Answer 50

3 in a triangular shape