Hematology, the study of blood , broadly encompasses the study of various blood-forming organs as well. Hematologists deal with diseases that cause changes in the blood, such as a deficiency of blood cells (anemia) or blood cancer (leukemia). A hematoma is a bruise caused by bleeding into the tissue. Blood consists of cells (blood cells) and blood plasma (fluid). The blood cells present are red (erythrocytes), white (leukocytes), and platelets (thrombocytes). Red and white blood cells are formed in the bone marrow; in a 20-year-old, approximately 300 billion are produced daily. Blood plasma consists mostly of water but also contains important salts, proteins, fats, and carbohydrates. Important proteins include albumin, which is also the most abundant, as well as proteins involved in blood clotting. If blood plasma is collected in a test tube, the contents will soon coagulate. If the sample is centrifuged, the coagulated (clotted) proteins settle at the bottom. The remaining liquid layer is called serum.
Functions of Blood
- Transport Functions
A: Transport of oxygen and carbon dioxide. Transport occurs via the red blood cells’ hemoglobin, a protein that can bind both oxygen and carbon dioxide.
B: Transport of absorbed nutrients.
C: Transport of waste products from cellular catabolism (catabolism = breakdown).
D: Transport of other important substances such as iron and hormones. - The Immune System
Both white blood cells and soluble proteins, such as antibodies, are essential. Immunology is the study of the body’s defense against foreign organisms. - Stopping Bleeding
Both platelets and clotting factors are vital. - Homeostasis
Homeostasis refers to the maintenance of a constant internal environment within the body’s organ systems. For cells to function properly, a delicate balance must be maintained among a number of factors, such as pH, salt concentration, and temperature. The constant circulation of blood is essential for this.
Blood cells
Erythrocytes —red blood cells—are the most important type of blood cell. They are nucleated and have a characteristic biconcave shape. Their hemoglobin content gives blood its red color. They transport oxygen.
Leukocytes —white blood cells—come in many different forms and perform various functions. What they all have in common is that they play a crucial role in immune processes.
Platelets are the smallest blood cells and are responsible for sealing damaged blood vessel walls to prevent bleeding.