LYMPHATIC SYS

• What is the pressure of blood at the arterial end of the blood capillary due to?


  The small diameter of capillaries and the pumping force of the heart
• What is tissue fluid?


  Blood plasma that occupies the intercellular space and bathes cells
• Why does tissue fluid not contain erythrocytes, platelets, and plasma proteins?


  Because these components are too large to diffuse out of the blood capillaries
• How does tissue fluid facilitate exchange in the body?


  It allows nutrients and oxygen to diffuse to cells and waste products to diffuse back to capillaries
• What happens at the venule end of the blood capillary?


  Blood plasma is hypertonic compared to the surrounding tissue fluid, leading to reabsorption
• What percentage of fluid that leaves the blood at the arteriole end returns to the venule end?


  85%
• How much fluid is lost from capillaries each day?


  About 4 litres
• What is the fluid collected from capillaries and returned to the blood called?

  Lymph
• What color is lymph?


  Pale yellow
• How does the structure of lymphatic capillaries differ from blood capillaries?


  One end of lymphatic capillaries is blocked or closed, while the other end connects to lymphatic vessels
• What do lymphatic capillaries merge to form?


  Larger lymphatic vessels
• What organs are part of the lymphatic system?

  Lymph nodes, spleen, thymus gland, bone marrow, tonsils, and appendix
• How is the flow of lymph aided?


  By heartbeat pulse, contraction of skeletal muscles, peristalsis, and pressure changes during breathing
• What role do one-way valves play in lymphatic vessels?


  They ensure lymph flows continuously to the heart and prevent backflow
• What are the two main lymphatic vessels?

  The thoracic duct and right lymphatic duct
• What areas does the right lymphatic duct receive lymph from?


  The right hand, chest, and right side of the head and neck
• What areas does the thoracic duct receive lymph from?


  The left side of the head, neck, chest, and all body parts below the ribs
• Where does the thoracic duct deliver its contents?


  Into the left subclavian vein
• Where does the right lymphatic duct transport lymph?


  Into the right subclavian vein
• What is the role of lymph nodes in the body?


  They produce and store lymphocytes involved in antibody production
• How does the lymphatic system complement the blood circulatory system?


  By returning excess tissue fluid to the blood flow
• What substances diffuse into the lacteal in the small intestine?


  Fats and fat-soluble substances
• What are lacteals?


  Lymphatic capillaries in the villus of the small intestine
• How are lipid droplets transported from the small intestine?


  To the thoracic duct and blood circulatory system through the left subclavian vein
• What are the main functions of the lymphatic system?


  • Body defense through lymphocyte production
  • Complementing the blood circulatory system by returning excess tissue fluid
  • Transportation of fat-soluble substances
• How does the lymphatic system interact with the blood circulatory system?


  • Lymphatic vessels collect excess tissue fluid and return it to the blood
  • Lymph nodes produce lymphocytes for immune response
  • Lymphatic ducts transport lymph back into the bloodstream