A number of organs in the human body have very restricted ability to regenerate after injury. For over 150 years, many research had been conducted regarding heart regeneration but many findings were extremely controversial (Carvalho and de Carvalho 2010). The heart is one of the most important organs as it’s responsible for the body’s oxygen and blood supply. The human heart is divided into four chambers and is enclosed in a fluid filled sac within the chest cavity. One of the least regenerative organs in the human body is the heart but if there is a regenerative response, it is small in comparison to that of other organs such as the liver and skin (Laflamme and Murry 2011). But why can’t the heart regenerate after a heart attack compared to other organs that can is the question and the cells that makes up the tissue can explain this.

The incapability of the human heart to regenerate after injury such as a heart attack (Myocardial infarction) poses a major difficulty in the cardiovascular medicine (Laflamme and Murry 2011). Heart attacks are caused by the disturbance of blood supply to parts of the heart, causing heart tissues to die, often due to the blockage of the coronary artery. The heart responds to a heart attack by scarring, which consequences in reduced cardiac function and to compensate for the reduced cardiac function, the heart then develops hypertrophy which in turn leads to heart failure (Lien et al. 2012). Marie et al. (1996) explain hypertrophy as the wall of the heart thickens in response to a heart attack, as the wall thickens the heart contracts less efficiently and pumps less blood around the body to tissues that leads to death. But the reason to why human heart can’t regenerate after a heart attack is due to the cells, cardiac myocytes which make up the tissues in the heart (Beltrami et al. 2001). Findings have shown that human cardiac myocytes quickly multiple during the foetal life, but the duplication of these cells decrease right after birth (Soonpaa and Field 1997). Thus when a human experiences a heart attack, the tissues in the heart which are made up of cardiac myocytes cells dies, but with the duplication of these cells to cease right after birth, is the major cause of why the human heart cannot regenerate after a heart attack.
But with that said; other organs in the human body such as the liver has the ability to regenerate.

The human heart is a major organ in the body that cannot regenerate but other important organs such as the liver can regenerate. The liver is an organ in the abdominal cavity with many functions such as detoxification of toxic agent in the body and energy is also stored there in the form of glycogen. It has the ability to regenerate even when 70% of the organ tissue has been removed, it has thought to evolved with this regenerative capability because of the important roles it performs in the body, particularly in filtering the blood from harmful substances (Baddour et al. 2012). When the liver is damaged such as liver cancer, the hepatocytes and sinusoidal cells decreases and contribute to compromised function. A study was conducted where 70% of the liver had been surgically resected with a large response of the hepatocytes cells gradually proliferating, after 10 days the liver is regenerated by compensatory growth of the remaining liver tissue, rather than recreating an exact copy of the lost tissues (Higgins and Anderson 1931). The ability of the liver to regenerate after resection is due to the ability of the hepatocytes cells having an unlimited capacity for division. While the hepatocytes cells in human liver divide only seldom under normal conditions but with loss of liver function such as surgically removing parts of it leads to rapid proliferation and restoration of functional liver tissue. The liver is not the only organ in the human body that can regenerate but one organ that is always regenerating is the skin.

The skin is the body’s largest organ with tissues that comes in direct contact with the environment. The skin plays important function with everyday functioning such as protection against radiation from the sun, regulation of body temperature, sensory senses and production of Vitamin D with help from the sun (Baddour et al. 2012). When the skin’s protective barrier is damage due to an injury, the body triggers a response called wound healing; the ability of the human skin to regenerate after extensive damage which can occur due to the presence of stem cells in the dermis and cells in the stratum basale of the epidermis, all of which is able to generate new tissue (Seifert et al. 2012).
With injury such as a cut through the epidermis into the dermis of the skin (from the outermost layer to the middle layer of the skin), bleeding occurs and the skin regenerative process will then begin (Heng 2011). Clotting mechanisms in the blood is then triggered and a scab, a hard coating on the skin is then formed within several hours. The scab then briefly restores the epidermis and blocks any microorganisms such as bacteria from getting in (Zhang et al. 2012). When the scab has completely formed on the skin, cells of the stratum basale begin to multiple by mitosis and drift to the edges of the scab (Seifert et al. 2012). About a week after the injury, the wound will be replaced with a new layer of skin. Without this process of the skin regenerating after damage, life may not be what it is today.

Evidently, the cells that make up the organs tissue play a huge role to whether it has the ability to regenerate or not. It is known that the heart is a major organ for human being and is critical for survival as the transporter for blood and oxygen around the body. When a heart attack is experienced the heart wall begins to thicken and the cardiac myocytes cells gradually dies. But once the cells are dead it does not the have the ability to replicate and hence not able to regenerate the heart. The research conducted over many years had better conclusion for other organs and its ability to regenerate such as the liver and skin. As modern medicine is rapidly growing, there may be someway in the future for the heart to also have this regenerative ability