01:447:245 Lecture Notes - Lecture 2: Hepatectomy, Zygote, Neoplasm
Document Summary
During embryogenesis, all cells divide until they specialize, and then stop dividing. But in certain tissues i. e. skin, cells continue to grow and divide through life, forming new cells. Sometimes this process goes wrong and cells divide regardless of signals to regular their division (old cells don"t die when they should) Clonal expansion of these deregulated cells can lead to a mass or tumor. Benign tumors aren"t cancer- grow only in one place. They can"t spread or invade other parts of the body. Treatment often involves surgery and benign tumors usually won"t grow back. But: if cells within that benign tumor gain the ability to spread beyond their boundaries then result is malignancy (invasive) Cancer is a term used for a set of diseases in which abnormal cells become malignant, divide without control and are able to invadeother tissues. Sometimes cells spread to other parts of body through blood and lymph systems and form metastases.
