The muscles

Question 1

what is a whole muscle made of

Answer 1

fasicles

Question 2

what is a fasicle made of

Answer 2

many muscle cells

Question 3

what are muscle cells made of

Answer 3

packed with myofibrils

Question 4

what do myofibrils hold

Answer 4

hold many sarcomeres

Question 5

what is a sarcomere made of

Answer 5

thick and thin filaments

Question 6

what is a thick filament made of and what kind of protein is it

Answer 6

myosin

Question 7

what is a thin filament made of and what kind of protein is it

Answer 7

actin (contractile protein) and troponin and tropomyosin (regulatory proteins)

Question 8

which organelles do a muscle cells house a lot of

Answer 8

sarcoplasmic reticula and mitochondria

Question 9

what is each sarcomere bound by?

Answer 9

a network of interconnecting proteins called Z lines (anchor thin filaments)

Question 10

what proteins holds myosin onto the z-line

Answer 10

titin

Question 11

what is the h-zone

Answer 11

contains thick filaments only; myosin

Question 12

what is the I band

Answer 12

contains thin filaments only (actin + troponin + tropomyosin)

Question 13

what is the A band

Answer 13

overlap of of thick and thin filaments

Question 14

what is the m band?

Answer 14

has proteins that help hold the myosin filaments in their regular arrangements

Question 15

what is the arrangements in Myofibrils

Answer 15

3-1 or 6-1

3 thicks filaments surrounded by 1 thin or 1 thick surrounded by 6 thin

Question 16

what are the zones/bands of a sarcomere

Answer 16

Z lines, h zone, I band, A band, M band

Question 17

what causes movement inside the muscles

Answer 17

the binding of actin to myosin

Question 18

what are the 3 sources of ATP in the muscles

Answer 18

creatine phosphate (donate Pi); oxydative phosphorylation; glycolysis

Question 19

what initiates the binding of actin and myosin in muscles

Answer 19

ATP and calcium

Question 20

how is ATP generated

Answer 20

the glycogen store in the muscles and the myoglobin stored in muscles is used by the mitochondria to make ATP

Question 21

what is the standard level of calcium inside the muscles

Answer 21

1E-9 m

Question 22

where is calcium stored in the muscles?

Answer 22

in the sarcoplasmic reticulum around the myofibrils in a muscle fiber (cell)

Question 23

how does calcium contribute to muscle contractions?

Answer 23

calcium binds troponin (on tropomysin in the thin filament) causing tropomyosin to slide away fro the actin exposing a actin binding site for mysosin which binds and results in contraction of muscle fibers

Question 24

what happens from the brain to release calcium

Answer 24

motor neuron sends an action potentiaal to the axon terminal at the nueromuscular junction and calcium influxes from the synapse into the nueron which releases vesicles filled with ACh

Question 25

how does acetylcholine contribute to muscle contractions

Answer 25

ACh binds to ACh receptors and allows sodium ions to enter the cell causing EPP which can turn into action potential if threshold potential is reached

Question 26

what happens if the threshold potential is reached?

Answer 26

the action potential travels down sarcolemma and activates DHPR receptor which activates Ryanodine receptors on the calcium containing Lateral Sacs of the sarcoplasmic reticulum and releases calcium

Question 27

how to stop a muscle contraction

Answer 27

remove ACh and reuptake calcium

Question 28

how to remove ACh

Answer 28

ACh esterase is a membrane enzyme that breaks down ACh into inactive metabolites of choline and acetate

Question 29

what happens during muscle fatigue [3]

Answer 29

local increase of inorganic phosphate build up lactic acid build up lack of energy source/energy depletion

Question 30

what are the 3 types of muscle fibers

Answer 30

I, IIa and IIx

Question 31

type I muscle fibers

Answer 31

slow oxidative

Question 32

type IIa muscle fibers

Answer 32

fast-oxidative-glycolytic

Question 33

type IIx muscle fibers

Answer 33

fast glycolytic

Question 34

effect of weight lifting on muscle mass

Answer 34

can double it

Question 35

what does endurance training do

Answer 35

delays fatigability

Question 36

how can exercise convert muscle types

Answer 36

convert IIx to IIa, but can't modify type I

Question 37

how to modify type I muscle fibers

Answer 37

change in genetic material of the exercised muscle cells - upregulating type IIa genes and downregulating IIx genes

Question 38

what is angiogenesis and how does it occur?

Answer 38

increase in blood vessels in muscle caused by exercise

Question 39

what does exercise do for mitochondria

Answer 39

increases the number in muscle cells

Question 40

what does resistance training do?

Answer 40

release growth hormone and testosterone that upregulates production of actin and myosin

Question 41

what does exercise do for storage ability

Answer 41

increases the storage ability of energy rich molecules in muscle cells