Muscles

Question 1

What is around a myofibril?

Answer 1

Endomysiuj

Question 2

When cardiac muscle starts to contract?

Answer 2

Influx of Ca2+ from the outisde

Question 3

Paraympathetic nerves from which nerve acts on the heart by lowering heart rate?

Answer 3

Vagus nerve

Question 4

which chemical is in charge of the regulation of contraction in smooth muscle?

Answer 4

Calmodulin

Question 5

Smooth muscles have calmodulin instead of?

Answer 5

troponin

ALL muscles have tropomyosin

Question 6

When calcium binds to calmodulin, what does it activate?

Answer 6

Myosin light chain kinase

Question 7

ATPase activity for smooth muscle occur by?

Answer 7

Myosin

Question 8

What modulates smooth muscle action potential?

Answer 8

Acetylcholine

Question 9

What does acetylcholine causes the erector pili to do?

Answer 9

Increases Ca entering the cell to erect the muscle

Question 10

Skeletal has ____ cells while smooth/cardiac has ____nuclei

Answer 10

skeletal: multinucleated

smooth/cardiac: 1 nuclei

Question 11

Direct source of energy for skeletal muscle?

Answer 11

ATP–> ADP + phosphate

Question 12

How does ATP get trasnported out of the mitochondrial membrane?

Answer 12

ATP ADP translocase

Question 13

what type of muscle are sarcolemma/sarcomere in?

Answer 13

Striated muscles

Question 14

Isotonic muscle contractions ?

Answer 14

H & I band get shorter

Question 15

Increasing load muscles does what to velocity?

Answer 15

Slow it down

Question 16

Gamma efferent motor fibers is for?

Answer 16

Stretch Receptors (Spindles), regulated stretch/muscle length & tone

Question 17

Inorganic phosphate is released from ADP in myosin when?

Answer 17

For a powerstroek

Question 18

What is responsible for dissocaition of phosphate group during muscle contraction?

Answer 18

Cocking action

Question 19

_____has ATPase action that turns ATP –> ADP + phophate.

Answer 19

Myosin: release of phsophate –> myosin powerstroke