Final answer:
Blood, a connective tissue, has functions including nutrient and gas transport, defense, and maintaining homeostasis. Its components, plasma, and formed elements (RBCs, WBCs, platelets) each have specific roles. The bone marrow is vital for hematopoiesis, the formation of blood's cellular elements.
Step-by-step explanation:
Functions and Components of Blood:
The primary functions of blood include transportation of nutrients and gases, defense against pathogens, and maintenance of homeostasis. Blood is a connective tissue composed of a liquid called plasma and cellular components such as red blood cells (RBCs), white blood cells (WBCs), and platelets. These components play crucial roles in the body's overall function.
Blood Plasma:
Blood plasma is the fluid component of blood, making up about 55% of its volume. It contains important solutes and plasma proteins, such as albumin, globulins (including antibodies), and fibrinogen, which are essential for clotting and immunity.
Formed Elements of Blood:
The cellular components include:
- Red blood cells (erythrocytes): They are responsible for carrying oxygen to body tissues and removing carbon dioxide, thanks to the protein hemoglobin.
- White blood cells (leukocytes): They are part of the immune system and help defend the body against infection and disease.
- Platelets (thrombocytes): They are critical for blood clotting, which prevents excessive bleeding.
Blood Cells and Nutrients:
Like all cells, blood cells require nutrients to develop properly. These nutrients are delivered through the blood itself, mainly via plasma.
Bone Marrow and Hematopoiesis:
The bone marrow is the primary site of hematopoiesis, the process by which all the cellular elements of blood are formed. This is especially critical for the constant renewal of RBCs and for the production of WBCs, especially during times of infection or illness.