Heartbeat And Heart Working Function
The heart is the pumping organ of the body responsible for circulating blood throughout the whole body. The primary function of the heart is to supply oxygenated blood to the collection, as oxygen is the crucial need of every organ to remain active.
Heart rate usually defined as the number of heartbeats per minute. An average resting heart rate considered between 60 beats to 100 beats per minute. However, it also varies individual to individual. The number of heartbeats below 60 is known as bradycardia (slow heart), while above 100 is known as tachycardia (fast heart). Several factors alter the average heart rate and its physiological factors, such as obesity, age, cigarette or alcohol consumption, diabetes, or any renal disease.
Human Heart functions:
The heart mediates the circulation of blood into the body through two primary pathways. One is the pulmonary circuit, along with a systematic course. The pulmonary circuit involves the transfer of deoxygenated blood from the right ventricle through the pulmonary artery into the lungs; then, oxygenated blood returned via the pulmonary vein into the left atrium of heart, then this blood moves into left ventricle upon contraction of the left atrium. After this, In the systemic circuit, oxygenated blood is circulated in the whole body upon contraction of the left ventricle. First, this blood moves into the aorta and then into arteries and in this way for the entire body. Accordingly, deoxygenated blood s circulated back into the heart from the whole body through the venous system. Any blockage (thrombus) or damage to the vascular wall affects normal heart function as well as heartbeat.
Normal functioning of the heart
Normal heart functions and beats controlled by Sinoatrial node (SA), while sympathetic as well as parasympathetic systems are significant regulators of SA. This sympathetic and parasympathetic system controls normal heart functions via accelerants and vagus nerves respectively. The accelerats nerves through sensitive input release norepinephrine into cells of the sinoatrial node and lead to an increase in heartbeat whereas, the vagus nerve provides the parasympathetic input and releases acetylcholine onto the cells of the sinoatrial node and give rise to decrease in pulses. The normal functions of the heart are distributed in some pathological conditions or in response to medication. Likewise, CNS stimulants interlinked with increased in a heartbeat while CNS suppressants lead towards a decrease in pulses. In addition to these, numerous factors are affecting the pulse and normal functions of the heart.
Some important facts of Human Heart:
The size of the human heart is usually equal to the size of the giant fist, weighing about 280-340 grams (10-12 ounces) in males while 230-280 grams (8-10 ounces) in females. Additionally, the human heart pumps nearly 5.7 liters (6 quarts) of the blood into the whole body; normal heartbeat is preferably considered between 60-80 beats per minute, while the pulse of newborns is nearly 70-190 beats per minute, relatively faster in comparison to the adult heartbeat. Moreover, the adult heartbeat approximately 100,000 times in one day, estimating about 3 billion heartbeats in the whole life period. The human heart is present in the middle of the chest, typically pointing slightly left.
Effect of some endogenous substances on Heartbeat and Heart functions:
Epinephrine and norepinephrine
Epinephrine and norepinephrine are the catecholamines that primarily secreted from the adrenal medulla. These catecholamines forms component of fight or flight response. Similarly, these catecholamines share these receptors binding sites, mainly beta-1 receptors, and leads towards the opening of sodium as well as calcium channels and ultimately providing their effect. Undoubtedly, the use of mediations which share their binding sites with catecholamines, leading towards enhancing rate of depolarization, this ultimately results in more rapid attainment of threshold and hence, shortens the period of repolarization. This results in an alteration in normal physiological functions of the heart along with disturbing normal heartbeat.
Disturbance in normal thyroid hormone levels also provokes alteration in a heartbeat as well as healthy heart functions. This dysregulation in normal thyroid hormones can be a consequence of numerous reasons. In recent days, cosmetics highly associated with disturbance in thyroid hormone levels, especially in females due to the presence of parabens (used as preservatives) in cosmetics. Additionally, the impact of these altered thyroid hormones on normal heart functions and heartbeat is relatively long in comparison to catecholamine.