How is apoptosis related to physiologic homeostasis?

This article will answer the question about how apoptosis is related to physiologic homeostasis. It will also cover in detail what apoptosis is, how it is different from necrosis, and what homeostasis is. The article will also cover the role of these three processes in the Human body. 

How is apoptosis related to physiologic homeostasis?

Apoptosis is related to physiologic homeostasis by increasing the efficiency of the functioning of organs and tissues in the body. 

The word “Apoptosis” is derived from Latin, which means “to fall off”, just as leaves fall off a tree. Leaves fall off a tree when they’re dead. Thus, apoptosis refers to the process where the cell inside the organism is, in a lot of ways, dying or committing suicide. 

Apoptosis is referred to as a process that occurs continually and is well regulated in order to maintain the homeostatic cellular balance in the body of an animal. Apoptosis is also known as Programmed Cell Death ( PCD). 

PCD is rarely observed in healthy animals directly as apoptotic cells are potential triggers for phagocytosis and are hence removed on an active basis from the environment.

In essence, apoptosis is a physiological response which eliminates cells that are unwarranted. It is an evolutionary mechanism that is present in almost all multicellular organisms. 

Apoptosis is also involved during the process of embryogenesis in helping to shape future adult forms such as limbs and fingers. It is also involved in the suppression of vestigial embryonic structures. This refers to the development of genital organs that are formed during mammalian sexual differentiation. 

Through the elimination of unwanted cells, apoptosis makes space for newer cells, a process called cell renewal. In higher vertebrates, apoptosis is generally employed to eliminate self-reactive lymphocytes during the differentiation process. It is again involved during the termination of immune responses to remove antigen-specific lymphocytes. 

Let’s take into consideration how our fingers are formed. The cells between our developing fingers were instructed to die from the time we were an embryo. If these cells weren’t instructed to die, we would have webbed hands or paddles of tissue. We would not have fingers at all.

The cells that died between our embryonic fingers, died in this process of apoptosis. This is why it is also known as programmed cell death. In programmed cell death, cells undergo a process of “cellular suicide” if and when they receive similar cues to do so. Apoptosis also involves the death of cells, but it is done in a manner that benefits the organism as a whole. In humans, it happens in order to let fingers develop, or by eliminating cells that can become cancerous in nature. Thus, this is why apoptosis is an important process for living beings.

Generally, apoptosis happens in cells that have been in the body for such a long period of time that they get worn out, and hence, need to make way for more efficient young cells. When this does not happen, it leads to cancer. Thus, apoptosis is a normal process, and when it does not take place, it leads to the development of cancer. 

However, if there is too much apoptosis in a human being with normal functioning, it can result in several neurodegenerative diseases in which cells that are not supposed to die to end up dying. These cells receive messages from some part of the body or the brain that is yet to be studied. When the cells of the lower part of the brain die, it causes Parkinson’s disease. Too much apoptosis can also lead to Huntington’s disease, Alzheimer’s disease, Lou Gehrig’s disease, and several other neurodegenerative disorders.


To summarise the discussion of apoptosis, we covered the following points:

  • It is a genetically regulated, naturally occurring form of cell death
  • It plays a role in several biological processes such as embryogenesis, ageing, and other diseases
  • Apoptosis molecular mechanisms are involved in detecting death signals and regulating genetic information. The activation of these effectors has also been identified
  • Treatments such as non-steroidal anti-inflammatories and various anti-cancer treatments are acted through apoptosis
  • Newer treatments for modifying the excessive or reduced amount of  apoptosis in a human body are being studied and developed. They will be more likely to be used from the next decade onwards.

Apoptosis vs. necrosis

There are two ways in which cells die in a multicellular organism, such as human beings. One way is in which they are killed by things that could harm them, like toxic chemicals or a physical injury. This process is known as necrosis.

The other way is programmed cell death which we discussed in detail above. Here, cells die because they were instructed to do so, a process called apoptosis. 

Apoptosis and necrosis occur in different circumstances involving different steps. However, it is generally understood that necrosis is a messy process, and can cause immune responses to inflammation. Whereas, apoptosis is a tidy process that splits the cells into small parcels which can be used by and recycled by other cells.

What is Homeostasis?

Claude Bernard, who was a French Physiologist, introduced the theory of homeostasis in the year 1865. The term was first used by Walter Bradford Cannon in the year 1926. 

Bradford derived the word homeostasis from Greek words ὅμοιος (pronounced as homos) and ἵστημι (pronounced as hístēmi). These terms translate into “similar” and “standing still” roughly. 

Homeostasis is a very crucial process for the survival of organisms. It is seen as resistance or the ability of the organism to maintain constancy even in the face of changes in the external environment. Homeostasis is described as a self-regulating process which tends to regulate internal variables that are necessary to sustain life.

Thus, homeostasis is the process in which an organism is able to maintain a stable internal environment irrespective of the changes occurring in the external environment.

Homeostasis is maintained by controlling several variables of the body including body temperature, blood pH, blood glucose levels, fluid balance, sodium, calcium, and potassium ion concentrations in the body.

If there is a breakdown or failure of homeostasis in the body of an organism, it can result in illness, diseases, disability, and in severe cases even death (Gordon et al., 2017).

The factors that affect homeostasis are:

  • Genetics
  • Physical fitness
  • Diet and nutrition
  • Toxins in the body
  • Psychological wellbeing
  • Side effects of medicines or medical procedures

Examples of homeostasis include:

  • Blood Glucose Homeostasis
  • Blood Oxygen Content Homeostasis
  • Core Body Temperature Homeostasis
  • The Volume of Bodily Fluids Homeostasis
  • Extracellular potassium and sodium concentration homeostasis.


The article covered in detail how apoptosis is related to physiologic homeostasis. It also explained apoptosis, necrosis, and homeostasis in detail and highlighted the differences between the two. We can conclude that apoptosis is related to physiologic homeostasis by increasing the efficiency of the functioning of organs and tissues in the body. Apoptosis is important to the immune system and also plays a role in the development and severity of cancer. The article will answer frequently asked questions about apoptosis in detail below.

Frequently Asked Questions: How is apoptosis related to physiologic homeostasis?

Why is apoptosis important in the immune system?

Apoptosis is important in the immune system because it plays a crucial role when it comes to controlling immune response, deletion of immune cells, cytotoxic killing, as well as recognising self-antigens in the body.

What would happen without apoptosis?

If there was no apoptosis, the cells in the body would not be instructed to die which would lead to unfettered proliferation, which can ultimately lead to cancer in complex organisms such as human beings.

Why is apoptosis better than necrosis?

In simple terms, apoptosis is natural and normal in maintaining the organism’s cellular balance. There are no symptoms resulting from apoptosis. However, necrosis can lead to uncontrolled changes and cause cellular imbalance. In fact, necrosis also usually has negative consequences and symptoms. 

Why is apoptosis important in cancer?

When there is a loss of apoptotic control in the organism’s body, it can lead to cancer cells surviving for a longer period. This gives the cells more time to accumulate and mutate which can increase tumour progression, deregulate cell proliferation, and can stimulate angiogenesis causing severe and usually last stages of cancer.


Cohen, I. Bernard, “Foreword”, in the Dover edition (1957) of: Bernard, Claude, An Introduction to the Study of Experimental Medicine (originally published in 1865; first English translation by Henry Copley Greene, published by Macmillan & Co., Ltd., 1927)

Gordon., Betts, J. Anatomy and physiology. DeSaix, Peter., Johnson, Eddie., Johnson, Jody E., Korol, Oksana., Kruse, Dean H., Poe, Brandon. Houston, Texas. p. 9. ISBN 9781947172043. OCLC 1001472383