What Is the Average Cell Life Span?
The average life span of a cell depends on the type of cell it is. There are approximately 10 trillion cells and about 200 types of cells in the average adult human body. Although some types of cells are short-lived, others remain in a person's body from before he or she is born until after he or she dies. The average cell life span varies from, for example, a few hours for certain blood cells, 10 days for taste receptor cells, a month for skin cells, 15 years for muscle cells and a lifetime for nerve cells.
Nerve cells, also referred to as neurons, specialize in conducting nerve impulses. Though there are quite a few types of neurons — motor neurons and sensor neurons, for example — for the most part. none these cells self-replicate. They’re in the body for a lifetime.
Muscle cells also come in different types: cardiac cells, skeletal cells and smooth cells. These cells contain protein filaments that aid in the contraction and relaxation of muscles, which is what produces movement. Although muscle cells do eventually die, they are also long-lived. The average cell life span of a muscle cell is about 15 years.
The aforementioned cells in the human body are the exception. Most of the body’s cells have a more frequent turnover rate. Some have a cell life span of a few months, and others live merely a few days or even just a few hours.
The cells that line the intestine, for instance, live an average of two to three days. The life span of a skin cell is about a month. Neutrophils, a type of white blood cells, live for only a few hours, up to a day. Liver cells may have a life span of eight to 16 months. Taste receptor cells live about 10 days.
Not only does the type of cell play a role in what the cell’s life span is, the general health of the cell also is a factor in how long it lives. For example, normal red blood cells live approximately three months. Sickle-shaped blood cells, which are part of a serious disorder, live only 10-20 days.
The average cell life span is based on the type and health of that cell. Every minute, an average of 300 million of the body's cells die. In the vast majority of cases, these cells are quickly replaced by new cells through a process call cellular mitosis.
Written by Maya Austen
