Question | Answer |
cell 2 cell junction that form mechanical n electrical connections between all cardiac contractile n conduction cells r called | gap junctions |
myocyte/contractile cell membrane is called | sarcolima |
filled with extracellular fluid and has extensions of plasma membrane penetrate into the cell n r open to the extracellular space | t-tubules |
the t-tubules allow 4 the movement of large amounts of------into the cell where it moves into the sarcoplasmic reticulum | calcium |
endoplasmic reticulum is called | sarcoplasmic reticulum |
sarcoplasmic reticulum store ---------- obtained from the t-tubules | calcium |
myosin, actin, troponin, tropomyocin | 3 contractile/motor proteins in the contractile cell |
myosin is referred to as a --------- protein with small projections called bridges or ===== | thick, heads |
thin, double | actin is referred to as ====== protein arranged in a ===== strand |
actin proteins contain binding sites | 4 myosin heads |
actin also includes the proteins | tropomyocin and troponin complex |
there are 3 parts to troponin | troponin I,T, and C |
troponin C | portion of the complex interacts with calcium |
located n the groove between the 2 actin strands and covers the myosin binding sites on the actin | tropomyocin |
sarcomere | a contractile unit of the actin n myosin proteins |
a conduction cell | generates an action potential |
the conduction cell === and causes=== gated sodium and calcium channels in the ===== to open | depolarizes, voltage, and gap junctions |
sodium and calcium | moves into the contractile cells |
na+ and ca++ causes the charge in the cell to become more==== and changes the ==== | positive, membrane potential |
the change in membrane potential causes==== channels to open and tons of na+ moves into cell | voltage gated fast sodium |
when na+ moves into cell membrane to on the action potential wave | depolarizes, also called phase 0 |
during phase 0, k+ channels are | closed |
tons of sodium move in the inside of the inner cell membrane become ---- and referred to as | positive, "overshoot" or phase 1 |
positive charge in "overshoot" causes======= to open and ==== starts moving into contractile cells from ====== | voltage gated slow calcium
calcium
extracelluar fluid |
phase 2 on the action potential wave is called | plateau |
the calcium moving into the cell during the plateau phase causes a voltage change inside the cell. | causes voltage gated calcium channel in the sarcoplasmic reticulum to open and tons of calcium moves in the sarcoplasm |
calcium binds to======which changes its shape/conformation | troponin c |
the shape change rolls ==== off the myosin binding active sites on the==== | tropomyocin, actin |
=== hydrolysis causes the myosin heads to change their shape. they move onto the myosin binding sites on the ====, this process is called=== | ATP,
actin
bridging |
as long as === and == are present the cross bridging continues | atp
ca++ |
the myosin heads shift and move | the actin forward |
in relaxation ===and binds to the myosin heads and they detach from the ===;everything moves back to its original position to get ready for the next contraction | atp
actin |
which type of calcium movement creates the electrical currents in the cardiac myocyte | calcium movement across the sarcolemma |
calcium movement out of the sarcoplasmic reticulum occurs by | diffusion, from higher to lesser concentration |
calcium moves back into the sarcoplasmic reticulum by | active transport, lesser to higher concentration |
calcium moves back into the sarcoplasmic reticulum during | diastole |