Cell of the living units of the body

-
The basic living unit of the body is the cell. Each organ is an aggregate of many different cells held together by intercellular supporting structures. Each type of cell is specially adapted to perform one or a few particular function. For instance, the red blood cells, numbering 25 trillion in each human being, transport oxygen from the lungs to the tissues. Although the red cells are most abundant of any single type of cell in the body, there are about 75 trillion additional cells of other types that perform functions different from those of the red cell. The entire body, then contain about 100 trillion cells.



Although the many cells of the body often differ markedly from one another, all them have certain basic characteristic that are alike. For instance, in all cells, oxygen reacts with carbohydrates, fat, and protein to release the energy required for cell function. Further, the general chemical mechanisms for changing nutrients into energy are basically the same in all cells, and all cells deliver end products of their chemical reactions into the surrounding fluids. Almost all cells also have the ability to reproduce additional cells of their own kind. Fortunately, when cells of a particular type are destroyed from one cause or another, the remaining cells of this type usually generate new cells until the supply is replenished.

Comments

Post a Comment

Popular posts from this blog

Pleural Effusion

-
Image
Pleural effusion , sometimes referred to as “water on the lungs,” is the build-up of excess  fluid  between the layers of the pleura  outside the lungs. The  pleura  are thin membranes that line the lungs and the inside of the chest cavity and act to lubricate and facilitate breathing. Differential Diagnosis Exudative malignancy, infections, connective tissue disease, pulmonary embolism, hemothorax, pancreatitis, chylothorax Trabsydatuve HF, hypoalbuminemia (GI losing enteropathy, cirrhosis, nephrotic syndrome, malnutrition), SVC obstruction, hepatohydrothorax, urinothorax, atelectasis, trapped lung, peritoneal dialysis, hypothyroidism, pulmonary embolism Note: pulmonary embolism, malignancy, and sar coidosis can present as either exudative or transudative effusions. HF following diuresis may become ‘‘pseudo exudative’’ (check albumin gradient) Clinical Features History dyspnea, cough, hemoptysis, chest pain, weight loss, fever, trauma, occup...
Read more

FNAC of Salivary Gland Tumors

-
Image
Fine Needle Aspiration Cytology (FNAC) of Salivary Gland Tumors Introduction: Salivary gland neoplasms though relatively uncommon are by no means rare, accounting for 3 % of all head and neck tumors. Distribution wise 80% of the tumors occur in parotid gland, 15% in submandibular gland and less than 1% in sublingual glands. The World Health Organization (WHO) has classified the tumors of salivary gland as primary or secondary, malignant or benign and by the tissue of origin. The five broad – categories of salivary gland tumors are: Malignant tumors: e.g. Mucoepidermoid Carcinoma, Acinic cell Carcinoma and Adenoid Cystic Carcinoma, Benign tumors: e.g. Pleomorphic Adenoma, Warthin’s tumor, Myoepithelioma, Soft Tissue tumors: e.g. Hemangioma, Hematolymphoid tumors: e.g. Hodgkin’s Lymphoma & Secondary tumors. Of the malignant tumors Mucoepidermoid Carcinoma is the most common neoplasm occurring most frequently in the parotid gland. Exposure to radiation has been thought to play or...
Read more

Crohn's Disease

-
Image
Crohn's disease causes inflammation of the small intestine. Although it may involve any part of the digestive tract from the mouth to the anus, it most commonly affects the last part of the small intestine, called the ileum, and the large intestine, including the colon and rectum. This is considered a chronic condition because it may recur at various times throughout your lifetime, with periods of remission in which you are free of symptoms. There is no consistently accurate way to predict when a remission may occur or when symptoms will return. The disease may occur in people of all ages, although most are diagnosed before the age of 30. However, it also can affect young children and older people in their seventies or beyond. Crohn's disease occurs most commonly in people living in northern climates and affects men and women equally. The condition can be inherited and is common in some families. About 20 percent to 25 percent of those with Crohn's disease have a close r...
Read more