Week 2 Day 3 Muscle Basics, CrossBridge cycle, controlling skeletal muscles, ATP, Fatigue

Question 1

What does the latin root myo mean?

Answer 1

Pertaining to muscle

Question 2

What does the latin root sarco mean?

Answer 2

Latin for flesh, referring to part of the muscle cells

Question 3

Are skeletal muscles involuntary or voluntary contraction?

Answer 3

Voluntary contraction

Question 4

Muscle Fiber is composed of many _____?

Answer 4

Myofibrils

Question 5

Are skeletal muscles mononucleated or multinucleated?

Answer 5

Multinucleated.

Question 6

Can skeletal muscles undergo mitosis?

Answer 6

No, they can’t undergo mitosis but then can go through hypertrophy (grow)

Question 7

What is a sarcoplasm?

Answer 7

The cytoplasm of a muscle fiber

Question 8

Waht is a sarcoplasmic reticulum?

Answer 8

the endoplasmic reticulum of a muscle fiber (stores CA)

Question 9

What is the sarcolemma?

Answer 9

The plasma membrane of a muscle fiber

Question 10

What is a sarcomere?

Answer 10

A contractile unit

Question 11

On a muscle fiber, what is a Z line to Z line?

Answer 11

A sarcomere

Question 12

What protein is thick filaments made of?

Answer 12

Myosin

Question 13

On a thick filament, what are the two binding sites it has

Answer 13

ATP and Actin binding sites

Question 14

On thin filaments, what binds to Troponin (protein) and what does does it do?

Answer 14

Ca2+ binds to troponin and uncoils the Tropomyosin, which blocks the Actin from binding to myosin (protein)

Question 15

What binds to myosin for thin filaments?

Answer 15

Actin

Question 16

When myosin binds to actin, what happens to the Zline? What is this process called?

Answer 16

The Z lines get closer to each other and spaces are eliminated.
-Crossbridges

Question 17

What is the cross bridge cycle?

Answer 17

The process of energized Myosin heads (jazz hands) that exist as ADP . Basically the cross bridge cycle is the process of myosin binding and unbinding to actin

Question 18

What happens to our skeletal muscles when we die?

Answer 18

No ATP is produced and the skeletal muscles contract.

Question 19

What two things does the cross-bridge cycle require?

Answer 19

ATP and Ca2+

Question 20

What is the NMJ in between?

Answer 20

A motor neuron and a muscle fiber

Question 21

How does the larger surface area of a skeletal muscle fiber affect depolarization, glucose, and atp

Answer 21

This makes depolarization take longer and it could hold more glucose and ATP

Question 22

What is isometric twitches as it pertains to muscle fibers. Give an example with dumbbells

Answer 22

Contraction without changing the length of the muscle.

-When you pick up dumbbells and do a farmers walk with them in your hands and arms to the side of your body

Question 23

What is isotonic twitches? Give an example with dumbbells

Answer 23

When contraction shortens your muscles.

-When you do you a bicep curl with dumbbells

Question 24

What are the 3 ways muscles get ATP?

Answer 24

• Creatine phosphate (CP + ADP—> ATP+C)
• Oxidative phosphorylation (adding phosphate) of ADP in mitochondria
• Glycolysis (anaerobic- does not require oxygen)

Question 25

Of the 3 ways the muscles get atp, which one is the slowest and most efficient?

Answer 25

Oxidative phosphorylation b/c it takes a while but yields 32ATP

Question 26

What can store oxygen in skeletal muscles?

Answer 26

Myoglobin

Question 27

What are the 2 different ways of classifying skeletal muscle fibers?

Answer 27

Crossbridge cycling speed or how they get ATP, whether it be oxidative phosphorylation or anaerobic glycolysis

Question 28

What are the 3 types of skeletal muscle fibers?

Answer 28

type 1: Slow oxidative (SO)
Type 2: Fast-oxidative-glycolytic
Type 2x: fast-glycolytic

Question 29

Of the 3 skeletal muscle fibers, which one would a sprinter have a majority of?

Answer 29

Most likely fast-glycolytic because it is the fastest

Question 30

Of the 3 skeletal muscle fibers, which one would a marathon runner most likely have?

Answer 30

-Slow oxidative because it fatigues the least

Question 31

What is poliomyelitis?

Answer 31

A virus that destroys motor neurons (mainly affects the legs)

Question 32

What is muscular dystrophy?

Answer 32

A genetic or autoimmune disease that has defects in Costameres (scaffolds muscles)

Question 33

What is Myasthenia Gravis?

Answer 33

Autoimmune disease when nAChR is attacked and muscle activation is inhibited.

Question 34

What is acute muscle fatigue?

Answer 34

Metabolic changes during muscle use which inhibits crossbirdge.

Question 35

What’s the difference between strains and sprains?

Answer 35

Strains occur when a muscle is twisted and a sprain occurs when a ligament is torn or stretched.