Structure Of The Heart Mitochondrion In The Heart Essay

VENTRICULAR MYOCYTE

Introduction
The heart of an organism contains a series of cells whose collective action assist in the blood pumping mechanism. Cardiac muscle cells have very many mitochondria which assist in the provision of the energy needed for the pumping mechanism. Structural arrangement of the heart is similar throughout the entire heart some of these cells originate from the connective tissue of the heart while the rest emanate from the heart valves. The cells are ventricular myocytes. Most occurring cells in the myocardium are the myocytes which are highly contractile. The structure of ventricular wall is unique. The left ventricle is thick-walled; it thickens more during contraction and collapses during relaxation.

The Cardiac muscle is striated muscles found on the heart walls. The main area of concentration is the myocardium. The myocardium has got three nuclei tissue and has continuous enclosures forming a series of well-organized layers of mus. It forms a thick centrally placed seal in between the outer epicardium, and the one found inside called the inner endocardium. The outer epicardium is visibly thinner than the inner endocardium. The muscles also entirely depend on good amount of blood and electrical action in order to distribute oxygen to the body; the muscles are considerably long and circular cells, they have endings that look alike and branch into separate units of closely occurring parts. The muscle fibers have connective tissues that give strength to the endomysium of skeletal muscle. (Pandit, 2002)
Cardiac contractions are repetitive and in this case closely occurring fibers are made to contract simultaneously. Contraction of the heart is aided by the electrical impulses carried in the cells and starts from the sinoatrial node that is found in the left atrium. The cells do not come into contact with one another during the beating process. They initiate independent beats; they can either come faster or slower but often come in the same frequency hence occurring in unison. When this fails, the result can lead to a dangerous heart condition known as arrhythmias.
The sinoatrial node functions as the pace setter of the rate and rhythm As a result of action of the electrical activity of the atria, The walls are caused to contract which makes the walls to contract. The heart depolarizes spontaneously hence bringing the autonomous behavior. Pacemaker potentials are triggered by sinoatrial nodes. In cases where pacemakers fail to act, non-pacemakers can take part. Electrical activity of the cells is visible on the walls of the cardiovascular system; this is made possible by the small time durations taken by the action of electric pulses. For instance, it is not possible to see the sinus node action but only the resultant contractions which come as a wave. During an exercise or any activity, the heart rate heightens to around 99 beats per minute and is because the body demands an enormous measure of oxygen which comes in contained in blood. (Pandit, 2002)

Conclusion

The cardiac muscle action is short lasting and differs in different parts of the heart. The heart has a specialized excretory system that also assists in the autonomous. Unique feature of the heart is that it has got a thickness which from one region to the other. Locations bring difference in force which is exerted upon it by prevailing atmospheric pressure. (Pandit, 2002)

References

Sandeep V. Pandit, 2002. Electrical Activity in Murine Ventricular Myocytes. University of Memphis Press.