Brief Blood Notes

Blood Components

• Plasma: 55% of blood, contains water (92%), proteins (7%: albumins, globulins, fibrinogen, regulatory proteins), and other solutes (1%: electrolytes, nutrients, respiratory gases, waste products).
• Formed elements: 45% of blood, include erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.

Blood Functions

• Transportation: Transports oxygen, carbon dioxide, nutrients, hormones, and waste products.
• Regulation: Regulates body temperature, pH, and fluid volume.
• Protection: Protects against blood loss and infection.

Plasma Composition

• Water: Solvent for transport.
• Proteins: Buffer against pH changes.
  • Albumin: Osmotic pressure, viscosity, and transport.
  • Globulins: Alpha and beta transport lipids and metal ions; gamma are antibodies.
  • Fibrinogen: Blood clotting.
  • Regulatory proteins: Enzymes and proenzymes.
• Other solutes: Electrolytes, hormones, nutrients, respiratory gases, wastes.

Hematopoiesis

• Formation of blood's formed elements.
• Red blood cell (RBC) production controlled by erythropoietin (EPO).
• RBCs live approximately 120 days.

Formed Element Abundance

• Erythrocytes > Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils

Formed Element Functions

• Erythrocytes: Transport oxygen.
• Neutrophils: Phagocytize bacteria.
• Eosinophils: Destroy parasites.
• Basophils: Release histamine and heparin.
• Lymphocytes: T cells and B cells for immunity.
• Monocytes: Become macrophages.
• Platelets: Aid in clotting.

Hemostasis

1. Vascular spasms: Vasoconstriction.
2. Platelet plug formation: Platelets adhere to collagen fibers and release chemicals to become sticky.
3. Coagulation: Fibrinogen converts to fibrin, forming a mesh that traps blood cells and platelets.

Blood Groups

• Antigens: Recognized by body as foreign.

• Antibodies: Recognize antigens, reside in plasma.

• Agglutination: Clumping due to antibody-antigen binding.

• Blood Types:

  • Type A: A antigens, anti-B antibodies.
  • Type B: B antigens, anti-A antibodies.
  • Type AB: A and B antigens, no antibodies.
  • Type O: No antigens, anti-A and anti-B antibodies.

Rh Factor

• Rh+ : Antigen present.
• Rh- : Antigen absent; antibodies appear after exposure.
• Hemolytic Disease of the Newborn (HDN): Rh- mother with Rh+ fetus; treated with RhoGAM.