Blood Composition and Functions

Composition of Blood

• Blood is a liquid tissue that makes up approximately 7% of an adult's body weight
• Composition:
  • Plasma (55%): liquid portion of blood
    • 92% water
    • 7% proteins (albumin, globulins, fibrinogen)
    • 1% nutrients, hormones, gases, waste products
  • Formed Elements (45%): suspended cells and platelets
    • Red Blood Cells (RBCs or erythrocytes)
    • White Blood Cells (WBCs or leukocytes)
    • Platelets (thrombocytes)

Functions of Blood

• Transportation:
  • Oxygen from lungs to body tissues
  • Carbon dioxide from body tissues to lungs
  • Nutrients from digestive system to body tissues
  • Hormones from endocrine glands to target cells
• Regulation:
  • pH balance
  • Body temperature
  • Blood pressure
• Protection:
  • Defense against pathogens (WBCs)
  • Blood clotting (platelets and plasma proteins)
• Waste removal:
  • Removal of waste products from body tissues

Blood Types

• ABO Blood Group System:
  • A (presence of A antigen on RBCs)
  • B (presence of B antigen on RBCs)
  • AB (presence of both A and B antigens on RBCs)
  • O (absence of A and B antigens on RBCs)
• Rh Blood Type System:
  • Rh positive (presence of Rh antigen on RBCs)
  • Rh negative (absence of Rh antigen on RBCs)

Blood Disorders

• Anemia: decreased RBC count or hemoglobin level
• Leukemia: cancer of WBCs
• Hemophilia: bleeding disorder due to clotting factor deficiency
• Thalassemia: genetic disorder affecting hemoglobin production

Blood Composition

• Blood makes up approximately 7% of an adult's body weight
• Plasma consists of:
  • 92% water
  • 7% proteins (albumin, globulins, fibrinogen)
  • 1% nutrients, hormones, gases, waste products
• Formed elements consist of:
  • Red Blood Cells (RBCs or erythrocytes)
  • White Blood Cells (WBCs or leukocytes)
  • Platelets (thrombocytes)

Blood Functions

Transportation

• Oxygen from lungs to body tissues
• Carbon dioxide from body tissues to lungs
• Nutrients from digestive system to body tissues
• Hormones from endocrine glands to target cells

Regulation

• pH balance
• Body temperature
• Blood pressure

Protection

• Defense against pathogens (WBCs)
• Blood clotting (platelets and plasma proteins)

Waste Removal

• Removal of waste products from body tissues

Blood Types

• ABO Blood Group System:
  • A: presence of A antigen on RBCs
  • B: presence of B antigen on RBCs
  • AB: presence of both A and B antigens on RBCs
  • O: absence of A and B antigens on RBCs
• Rh Blood Type System:
  • Rh positive: presence of Rh antigen on RBCs
  • Rh negative: absence of Rh antigen on RBCs

Blood Disorders

• Anemia: decreased RBC count or hemoglobin level
• Leukemia: cancer of WBCs
• Hemophilia: bleeding disorder due to clotting factor deficiency
• Thalassemia: genetic disorder affecting hemoglobin production

Learn about the composition of blood, including plasma and formed elements, as well as its various functions such as transportation and regulation.