Answer:
Option). about 20 percent of the calcium ion required for contraction comes from outside the cell.
Explanation:
Calcium ions play an important role in cardiac muscle physiology. Calcium ions influx is responsible for plateau phase after depolarization. Calcium ions also play role in muscle contraction with the help of troponin (regulatory protein).
For contraction, about 20 percent of calcium ions are supplied from outside of the cell, while rest of the calcium ions are released from SR (sarcoplasmic reticulum).
Thus, the correct answer is 'forth option.'
Answer:
What would you tell them about your functions as a medical assistant?
-What would you say to those who asked if you looked through the microscope and reported your findings?
-One student asks what type of training one would need to work solely in microbiology in a laboratory setting. How would you answer her?
Explanation:
The SA Node is the heart's normal pacemaker. When the SA Node depolarizes, electrical signal spreads through the atrial muscle causing contraction.
Explanation:
Inherent rhythmicity / automaticity - The property of the pacemaker cells of the heart to start electrical sequence of depolarization and repolarization.
SA Node or Sino-atrial Node generates the electrical signal.
The electrical signal passes through internodal pathways, atrial fibres, atrioventricular node (AV Node), the bundle of His, Purkinje fibres, right bundle branch, left bundle branch.
Systole - Contraction of cells when the electrical signal of depolarization reaches the contractile cells.
Diastole - Relaxation of cells when the electrical signal of repolarization reaches the myocardial cells.
