Question

The longest living cells amongst the following are
A) RBC
B) B cells
C) T cells
D) Neurons

Answer 1

Hint: The longest living cells are the ones which are still functioning in old age.

Complete answer:
Although our bodies are continuously replenishing their cells, some just stick around for a longer time than the others.
The longest living cells are ‘Neurons’. Neurons are unique because of the fact that the mature cells oppose division to create new cells after development in the foetus. While other cells in the body die and regenerate, many neurons remain the same throughout a person’s lifespan. On average, the body cells are replaced every 7 to 10 years. But those numbers hide a huge inconsistency in lifetime across the distinct body organs.
Lifespan of different body cells:
-RBCs have a lifespan of 120 days.
-Lymphocytes (WBC) have a lifespan of a few days or months or few years.
-Monocytes (WBC) have a lifespan of about 10-20 days.
-Granulocytes have a lifespan of about 4 to 8 hours when circulating in blood and about 4 to 5 days in the tissues.
-Brain cells have a maximum longest life span than the above cells.

Additional Information:
Neurons serve a special purpose of sending signals from one part of the body to another part. These messages are known as nerve impulses. For example- If a person wants to walk or run, neurons make it possible for the brain to tell the legs to move. However, not all neurons are created in an equal manner. Although they range in size but some neurons are about 3 feet long. The spectacular length of neurons makes them the longest cells in the body. On an average, the human brain is made up of more than 100 billion neutrons.

So, the correct answer is ‘Neurons’.

Note: Neurons are the structural and the functional unit of the nervous system. Neurons are known as the functional unit of the neural system because the several functions of the nervous systems are primarily the functions of the neurons.