Answer:
The prolonged electrical depolarization of cardiac muscle cells -that occurs during contraction- is due primarily to the persistent influx of calcium ion
Explanation:
The action potential of the heart muscle is longer with respect to skeletal muscle (around 300 milliseconds), and this is due to the activity of calcium (Ca⁺⁺ ) in the intracellular compartment.
The initial depolarization of cardiac muscle fiber depends on the entry of sodium (Na⁺) into the cell. However, for the action potential to occur and be maintained, Ca⁺⁺ must increase its cytoplasmic levels, which depends on:
- The increase in intracellular sodium induces the release of Ca⁺⁺ from the sarcoplasmic reticulum.
- Calcium entry from the extracellular space through the voltage dependent Ca⁺⁺ channels.
- The entry of extracellular Ca⁺⁺ causes the release of more Ca⁺⁺ ions by the sarcoplasmic reticulum, further increasing its intracellular concentration.
This is how the ion that guarantees the duration of the action potential of the cardiac muscle cell is the Ca⁺⁺.
Learn more:
Calcium, sodium and cardiac muscle cells brainly.com/question/4473795
A. when evaluating a source for reliability, if they are talking about a product from a company that sponsors them they may not be honest, or if they are sponsored by a reliable company they can be trusted it depends what way you look at it.
Answer:
Exercising
Explanation:
This happens because, when you exercise, the blood vessels in your muscles dilate (vasodilation) and as a consequence, the rate of blood flow is faster. The increased blood flow delivers more oxygenated blood to the working muscle.
20 percent available at the highest tropic level. There is less at the top of the food chain because it has ate things from possibly all areas of the food chain and each level is consuming from lower parts of the chain than it. So with the entire food chain eating on what the top eats there is gonna be less for the top
