Quiz 1 ( structure and function of muscle)

Question 1

What is Epimysium?

Answer 1

Connective tissue that surrounds ENTIRE muscle/ gives it shape

Question 2

What is Perimysium?

Answer 2

Connective tissue that surrounds each fascicle individually.

Question 3

What is a fascicle?

Answer 3

small bundle of fibers wrapped in Perimysium

Question 4

What is Endomysium?

Answer 4

Connective tissue that covers EACH muscle fiber

Question 5

What is the correct order from SMALLEST TO LARGEST ? peri, endo, epi?

Answer 5

ENDO- PERI-EPI

Question 6

what is a myocyte?

Answer 6

multi nucleated cells

tube like structure

Question 7

What are satellite cells?

Answer 7

Undifferentiated cells of musclefibers

Question 8

what/how is muscular membrane damage created?

Answer 8

Resistance training which ACTIVATES satellite cells which plays a key role with muscle growth/repair

Question 9

How many stimuli activate the satellite cells which leads to myogenesis of any specific fiber type?

Answer 9

Seven

Question 10

What does tintin do?

Answer 10

provides elasticity and stabilizes myosin

Question 11

What are the two binding sites of myosin?

Answer 11

Actin binding site

ATPase site

Question 12

what is the excitation-contraction coupling?

Answer 12

Calcium binds to troponin
Cooperative conformational changes takes place in troponin-tropomyosin system
The Inhibition of actin and myosin interaction is released
Crossbridges of myosin filaments are attached to actin filaments
Tension is exerted and/or the muscle shortens by sliding filament mechanism

Question 13

What is the Z line

Answer 13

Actin molecules are bound to the Z line, which forms the borders of the sarcomere. Other bands appear when the sarcomere is relaxed

Question 14

After the power stroke of the crossbridge that causes the sliding of the thin filaments, what happens next in contraction?

Answer 14

The binding of ATP to the crossbridge, which results in the crossbridge disconnecting from the actin
The hydrolysis of ATP, which leads to the re-energising and repositioning of the crossbridge
Cessation of AP- reuptake of Ca2+ into Sarcroplasmic reticulum
relaxation

Question 15

What are the two components of muscle fibers?

Answer 15

Sarcolemma and Plasmalemma

Question 16

What is the Sarcolemma

Answer 16

A structure that is made up of the plasmalemma and basement membrane

Question 17

What is the Plasmalemma

Answer 17

A plasma membrane that surrounds EACH muscle fiber

Question 18

What does the plasmalemma assist in?

Answer 18

The transmission of the action potential from the motor neuron to the muscle fiber

Question 19

What is the motor unit?

Answer 19

motor neuron and all the muscle fibers it innervates

Question 20

Where are satellite cells located?

Answer 20

between plasmalemma and basement membrane

Question 21

What is the sarcoplasm

Answer 21

Gelatin like substance that fills the space between MYOFIBRILS
contains dissolved proteins, minerals, glycogen, fats an organelles ( mitochondria and others that promote muscle growth/ repair)

Question 22

What are transverse tubules

Answer 22

T tubules

Extension of plasmalemma, located in sarcoplasm that presses along muscle fiber

Question 23

What is the sacroplasmic reticulum

Answer 23

longitudinal network of tubules that parallel the myofibrils and loop them around

Question 24

What is stored in the sarcoplasmic reticulum

Answer 24

calcium

Question 25

What is a myofibril

Answer 25

smaller than the whole muscle fiber | contains two contractile proteins - actin ( thin) myosin (thick)

Question 26

How are cross bridge's formed

Answer 26

many myosin heads | crossbridge interacts with thin filaments

Question 27

What are the three proteins that make up thin filaments

Answer 27

Actin, tropomyosin and troponin

Question 28

what is the tropomyosin strand also known as

Answer 28

Protein strand

Question 29

What binds to Tnc to make myosin?

Answer 29

Calcium

Question 30

What is the sliding filament theory

Answer 30

When each sacromere which contains thin and thick filaments overlap and SLIDE PAST eachother when the muscle contracts ( shortening of muscle) Cross bridge cycling creates the molecular basis for this to happen

Question 31

When is muscle contraction initiated?

Answer 31

when muscle fibers are stimulated by a nerve impulse AND calcium ions are released

Question 32

What are the three types of muscle action

Answer 32

isometric, concentric and eccentric

Question 33

What is isometric muscle movement

Answer 33

Muscle tension= muscle load | no change in length of muscle when tension is developed

Question 34

what is concentric muscle movement

Answer 34

muscle tension > muscle load muscle shortens while developing tension think of CONSTRICTING both start with CON so muscle is shortening like constricting

Question 35

what is eccentric muscle movement

Answer 35

muscle tension > muscle load muscle trying to shorten but is being forced to lighten ex- think of doing a bicep curl ( when lowering the dumbbell)