The largest cell in the human body is the ovum, also known as the egg cell. It measures approximately one millimeter in diameter.
While the ovum is often considered the largest cell, it's important to note that some neurons, particularly those extending from the spine to the toes, can be significantly longer. However, these neurons have a much smaller diameter than the ovum.
The ovum is a highly specialized cell responsible for the single function of fertilization. It is equipped with a large amount of cytoplasm and nutrients to sustain the developing embryo. Other cells, such as skeletal myocytes and megakaryocytes, are also relatively large but are not as large as the ovum.