Blood, Tissue Fluid, Lymph

• What are the main components of blood?

  Plasma, erythrocytes, leucocytes, and platelets
• What is the primary function of plasma in blood?

  To transport dissolved substances such as oxygen and nutrients
• What is tissue fluid primarily composed of?

  Water, oxygen, and dissolved nutrients
• How does hydrostatic pressure affect the formation of tissue fluid?

  It pushes fluid out of the capillaries into surrounding tissue
• What remains in the capillaries during the formation of tissue fluid?

  Red blood cells, most white blood cells, and platelets
• What is oncotic pressure?

  Pressure that tends to pull water into the capillaries from the tissues
• How do hydrostatic and oncotic pressures interact at the arteriole end of a capillary?

  Hydrostatic pressure is greater than oncotic pressure, causing fluid to leave
• What happens at the venule end of a capillary regarding fluid movement?

  Oncotic pressure is greater than hydrostatic pressure, so fluid enters the capillary
• What is the effective pressure at the arterial end of a capillary?

  1. 3 kPa
• What is the effective pressure at the venule end of a capillary?

  • 1.0 kPa
• What is lymph and how does it differ from tissue fluid?

  Lymph has less oxygen and nutrients than tissue fluid
• What do lymph nodes do?

  They filter lymph and remove bacteria and foreign material
• What are lymphatic vessels and their primary function?

  Thin-walled, valved structures that carry lymph and support immune functions
• Where are lymphatic capillaries primarily located?

  Throughout most tissues of the body, particularly connective tissue
• What are the key processes involved in the formation and drainage of tissue fluid?

  • At the arteriole end: Hydrostatic pressure > Oncotic pressure → fluid leaves capillary
  • At the venule end: Oncotic pressure > Hydrostatic pressure → fluid enters capillary
  • CO₂ and waste products diffuse into blood or drain into lymph vessels
• What are the differences between blood, tissue fluid, and lymph?

  • Blood: Contains red blood cells, white blood cells, platelets, and plasma proteins
  • Tissue fluid: Contains oxygen and nutrients, but no red blood cells or large proteins
  • Lymph: Contains lymphocytes and fatty material, with less oxygen and nutrients than tissue fluid
• What is the role of oncotic pressure in the circulatory system?

  • Oncotic pressure pulls water into capillaries from tissues
  • It helps maintain fluid balance in the blood vessels
  • It counteracts hydrostatic pressure
• What is the significance of lymph nodes in the lymphatic system?

  • Filter lymph to remove pathogens
  • Swelling indicates increased lymphocyte production
  • Essential for immune response