cardiac muscle structure and function

Question 1

cardiac muslces are ___

Answer 1

striated

Question 2

Cardiac muscle are not under ___ ____ control

Answer 2

direct neural

Question 3

Ca2+ binds to ___ to regulate actomysosin interaction

Answer 3

troponin

Question 4

Cardiac muscles are ___, ____, and ______ than skeletal muscles

Answer 4

shorter, narrower, richer in mitochondria

Question 5

ATPase activity of myoscin is ___ in cardiac than skeletal

Answer 5

slower

Question 6

Gap junctions allow for

Answer 6

low resistance pathway for electrical currents

Question 7

Desmosomes provide

Answer 7

adhesion/assure force generated in one cell passes to other

Question 8

Cardiac muscle cells connect with each other through _______

Answer 8

intercalated disc

Question 9

Intercalated discs coincide with ____, which contains ___ and ____

Answer 9

z discs,

desmosomes and gap junction

Question 10

myofiber = ?

Answer 10

small bundle of muscles

Question 11

Myofibirils

Answer 11

end to end arrays of identical sarcomeres

Question 12

Sarcomeres

Answer 12

contractile units

Question 13

Thin filament

Answer 13

actin

Question 14

Thick filament

Answer 14

myosin

Question 15

Actin binds ___ and ___

Answer 15

tropomyosin; troponin

Question 16

Myosin is composed of ___

Answer 16

2 heavy chain, 4 light chain

Question 17

Troponin C is a ___shaped protein with __ Ca binding site

Answer 17

dumbell

one (skeletal has 2)

Question 18

Troponin I - Unique N terminal extension of __ amino acid; PKA ___ for ___ responsiveness of heart

Answer 18

32
phosporylate
adrenergic

Question 19

Mechanism behind length - tension relationship

Answer 19

extend overlap, change in sensitivity to myofilament to ca, increased Ca release