Skeletal Muscle

Question 1

What is the muscle belly?

Answer 1

Whole muscle composed of many individual muscle fibres

Question 2

What are the Epimysium, perimysium and endomysium

Answer 2

Connective tissues that surround the muscle belly, fasciculi and muscle fibres respectively

Question 3

What is the actin

Answer 3

Thin protein filament found in the muscle cells that together with myosin forms sarcomeres

Question 4

What is the myosin?

Answer 4

Thick protein filament that together with actin form sarcomeres

Question 5

What is the sarcomeres

Answer 5

The contractile units of skeletal muscle. They are composed to 2 myofilaments, actin and myosin

Question 6

What is the tropomyosin

Answer 6

Threadlike spirals that wrap around the actin filament which covers the myosin binding site which prevents myosin attachment during the relaxed state

Question 7

What is the troponin

Answer 7

A calcium receptor that sits on top of troponin.

In the presence of calcium it pulls tropomyosin away from the myosin binding site and allows myosin to bind to the actin filaments and the sliding filament mechanism to commence

Question 8

What is the myosin cross bridge

Answer 8

The arm and head of the myosin filaments which extends to bind to the actin filament

Question 9

What is the sarcoplasmic reticulum?

Answer 9

A system of membranous sacs that surrounds the myofibrilis.

The sarcoplasmic reticulum stores calcium and regulates its release during muscular contraction

Question 10

What are slow twitch muscle fibres

Answer 10

Muscle fibre that uses oxygen to produce energy. They are associated with endurance based Activities

Question 11

What are fast twitch muscle fibres?

Answer 11

A type of muscle fibres that has a high glycotic capacity. They are associated with speed and power based activities

Question 12

What is a motor unit

Answer 12

The motor nerve and group of muscle fibres that it controls

Question 13

All of none law?

Answer 13

If a motor impulse is of sufficient fibres within it will contract to their maximum possible extent

Question 14

What is spatial summation

Answer 14

An increase in responsiveness (not done )

Question 15

What is the fasciculi?

Answer 15

Bundle of muscle fibres that make up the muscle belly

Question 16

the 5 stages of sliding filament thoery

Answer 16

1. preparing the binding site
2. power stroke
3. binding of atp
4. the ratchet mechanism
5. return of the calcium ions back onto sarcoplasmic reticulum.

Question 17

What are the 3 factors that affect the strength or force of muscle contraction - variation

Answer 17

• recruitment = multiple unit summation
• frequency = wave summation
• timing = synchronicity of motor unit stimulation; spatial summation

Question 18

what is innervation

Answer 18

how the motor neuron transfers a nerve to the muscle fibers

all or none law

Question 19

what are the long term physiological benifits to the neuromuscular system in resistant training

Answer 19

efficient and effective muscle contraction:

• recruitment of more motor units
• muscle hypertrophy
• hypertrophy of fast twitch muscle fibers
• hyperplasia of fast twitch muscle fibres- conversion type 2b to type 2a

Question 20

what is the part of the brain that controls of of muscular movements

Answer 20

cererbellum