Explain how heart contraction triggered
Explain how heart contraction triggered?
Expert
Heart contraction is independent from neuronal stimulus (although it can be modulated by autonomous nervous system). In heart, there are pacemaker cells which trigger by themselves the action potentials which start the muscle contraction. Such cells are concentrated at two special points of the heart: the sinoatrial node (that is, SA node) positioned in the superior part of the right atrium and the atrioventricular node (that is, AV node) positioned near the interatrial septum.
The action potentials produced by depolarization of the SA node cells propagate cell to cell all through the atria generating the atrial contraction. The atrial depolarization as well propagates to the AV node which then transmits the electric impulse to the ventricles via specialized conduction bundles of the interventricular septum (that is, the bundle of His) and then to the Purkinje fibers of the ventricle walls causing the ventricular contraction. (Atrial contraction leads the ventricular contraction for blood to fill the ventricles prior to the ventricular contraction.)The re-polarization of the SA node forms the atria relax and then the ventricles relax as well.
Name the type of muscle tissue which performs the peristaltic movements of intestines?
Specify three main signs of the diabetes?
Define the term direct development? Is there a larval phase in the planarias?
Why is the AIDS treatment frequently done with the drug cocktail?
Describe oligopeptide in short? How is it distinct from a polypeptide?
How does alkalosis is corrected through the breathing process?
Explain the capillarity? How this mechanism is chemically explained? Specify the relevance of the capillarity for transport of the water in the plants?
Define the term Report studio?
Profit & Loss (P&L) Management: In brief it is managing the income and expenditure structure to give a Net Operating Profit for a business. Knowing what impacts the numbers is necessary and needs critical thinking skills. The P&L can be se
It is just the reverse of the downward communication. It flows upward from a subordinate to the superior through middle managerial levels along the line. Such communication is of two types: Feedback if information in which subordinates convey a message to the top executive in response to
18,76,764
1944587 Asked
3,689
Active Tutors
1417862
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!