Human Health and disease Part 5 CANCER Noncommunicable

Human Health and disease Part 5( CANCER)

Non-communicable diseases • They are also known as non-infectious disease. • These are the diseases that cannot be transmitted from one person to another and are not caused by pathogen. • They occur mainly either by the nutritional deficiency or genetic inheritance e. g. cancer , scurvy.

Type of non communicable disease 1. 2. 3. 4. Cancer Deficiency diseases Degenerative diseases Allergic diseases

Cancer • It is uncontrolled growth of normal cells which loses its capacity to control cell division, thus producing abnormal cell development. • The gene of cancer responsible for transformation is oncogene. (2016) • Tumour is a mass of cells formed due to the uncontrolled division of cells.

Characteristics of cancer cells a) Cancer cells never differentiate. They continue to divide, cause more damage and invade new tissues. b) Cancer cells have an asymmetrically shaped-nucleus that is larger than normal. c) Cancer cell have uncontrolled growth. d) The spread of cancerous cell from one part of the body to other part is called metastasis. Note : Metastasis: - it refers to the transfer of disease from one part of the body to another that is not directly connected with it.

• Neoplasm refers to the new growth of cells(abnormal growth) that occurs in the body. In other words it is an abnormal mass of tissue that results when cells divide more than they should. • Tumour is formed by masses of neoplasm which increase in size and disrupt the normal cells. A tumour may or may not be cancerous. Initially the rate of growth of tumour is generally slow but later it becomes very fast. • Types of tumour: i. Benign or non-malignant tumours ii. Malignant tumours(cancerous tumours)

• Benign tumour : - They remain restricted to their original location and does not spread in the entire body. • Malignant tumour: - it is the mass of cells called neoplastic or tumour cells. They grow rapidly, invade and damage the surrounding normal cells by proliferating to other body part through blood and body fluids. This cancerous activity of malignant tumour is called metastasis.

Benign or non-malignant tumours Malignant tumour They are enclosed in the connective. They are not enclosed in any specific tissue They remain confined to the site of their origin only. They are not confined to the orginal tissue. They may grow in size but do not spread to other parts of the body. (they are incapable of indefinite growth e. g. warts) The cancerous cells are carried by blood or lymph to other parts of the body where they spread secondary Growth of a tumour may cause pain As the cancerous cells grows if it presses against some vital organ rapidly , they kill other normal or tissue cells. The spread of secondary tumours is invariably fatal.

Malignant tumours are of following types: a) Carcinoma(cancer of epithelial cells) b) Sarcoma( cancer of connective and muscular tissues) c) Leukemia (blood cancer) Carcinogenes(cancer causing factor): A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis, the formation of cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes

Causes of cancer 1. Overexposure to ionizing radiations like X-rays, UV rays and gamma rays. 2. Chemicals like nicotine, caffeine, steroids and air pollutants may cause cancer of lungs, brain, breast or blood. 3. Several genes called cellular oncogenes (c-one) have been identified in normal cells which on activation under certain condition could lead to cancers. 4. Chronic physical abrasions of skin produce skin cancer.

DETECTION OF CANCER • • • Detected by blood and bone marrow test. Biopsy Radiography. CT Scan(computed Tomography) Magnetic Resonance (MRI)

Treatment of cancer

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