Functions of Blood

• The three primary functions of blood are: Transportation, regulation, and protection.
• Blood transports various substances throughout the body such as gases, nutrients, wastes, and hormones.
• Oxygen is transported by blood from the lungs to all cells in the body and Carbon dioxide is carried by blood to the lungs for elimination
• The bloodstream delivers nutrients from the digestive tract and storage sites to different parts of the body
• Waste products are carried by the blood to the liver for excretion as bile or to the kidneys for excretion as urine
• Hormones produced by glands are transported to their target organs by blood
• Keep in mind: Albumin is the main protein in the blood that helps maintain water balance and carries molecules around the body. It is roughly 60% of the plasma proteins in the blood.
• Plasma proteins also serve as carriers for other substances like lipids, vitamins, and minerals.
• Bloods primary function is to distribute substances around the body.
• Blood regulates body temperature, chemical balance, and water balance. Blood helps maintain the body temperature through plasma and blood flow. Plasma can absorb or release heat, and when blood vessels expand (vasodilate), blood flows slowly, causing heat loss. This happens when the external environment is hot. In contrast, when the external environment is cold, blood vessels contract (vasoconstrict), causing less heat to be released.
• Platelets are important because they repair damaged blood vessels. That is the ONLY thing platelets do! Platelets and plasma proteins repair damaged blood vessels.
• Hemostasis helps maintain blood in its fluid state and stops blood from leaking out of a damaged blood vessel through clot formation. There are three steps of hemostasis.
• The first step of blood homeostasis is vascular spasm, or vasoconstriction, where the blood vessels constrict to reduce blood loss. Reducing blood loss for several hours, this process works best with small blood vessels.
• The second step of blood homeostasis involves platelet plug formation. Platelets adhere to the epithelial wall of the blood vessel and aggregate by sticking together, creating a temporary seal over the damaged site.
• The third step of blood homeostasis is blood coagulation, also known as blood clotting. It is the use of fibrin threads to form a mesh around the platelet plug, which acts as a molecular glue, firmly attaching the plug to the damaged site. The resulting clot facilitates wound healing by trapping red blood cells and platelets at the affected site.
• The first step of blood homeostasis is vascular spasm (vasoconstriction). The second step of blood homeostasis is platelet plug formation. The third step of blood homeostasis is blood clotting (blood coagulation).
• So blood homeostasis happens in this order: The damaged blood vessels constrict -> the platelets stick together and form a plug -> red blood cells are recruited to the injured site -> the site of the wound is then healed.