Anaphy - Lymphatic Syste,

• Two parts of the Lymphatic System

  1. Lymphoid Vessels

  2. Lymphoid tissues ad organs
• It transport fluids that have escaped from the blood back to the cardiovascular system.

  Lymphoid Vessel

  
• These house phagocytic cells and lymphocytes, which play essential roles in body defense and resistance to disease.

  Lymphoid Organs and Tissues
• 1._____________, as well as any 2.___________ that escape from the blood, must be carried back to the blood if the vascular system is to have sufficient blood volume to continue to operate properly.

  1. Excess tissue fluid

  2. Plasma proteins
• Abnormal accumulation of fluid in the tissues.

  Edema or swelling

  
• Excessive _____________ impairs the ability of cells to make exchanges with the interstitial fluid and ultimately, the blood.

  Edema

  
• Its function is to form an elaborate drainage system that picks up this excess interstitial fluid, now called lymph, and returns it to the blood

  Lymphatic Vessels
• It means clear water

  Lymph
• The water fluid or excess interstitial fluid in the lymph vessels collected from the tissue spaces.

  Lymph
• It forms a one-way system, and lymph flows only toward the heart.

  Lymphatic Vessels
• The other term for lymphatic vessels.

  Lymphatics
• It weaves between the tissue cells and blood capillaries in the loose connective tissues of the body and absorb the leaked fluid.

  Lymph capillaries
• Lymphatic capillaries' edges of the endothelial cells forming their walls loosely overlap one another, forming flaplike ______________ that act as one-way swinging doors.

  Minivalves

  
• This structure, anchored by fine collagen fibers to surrounding structures, gape open when the fluid pressure is higher in the interstitial space, allowing fluid to enter the lymphatic capillary.

  Minivalves (in the lymph capillary)

  
• What happens to the lymph if the pressure is higher inside the lymphatic vessel than the interstitial space?

  The endothelial cell flaps are forced together, preventing the lymph from leaking back out and forcing it along the vessel.
• True or False?

  
  

  Proteins, and even larger particles such as cell debris, bacteria, and viruses, are normally prevented from entering blood capillaries, but they enter the lymphatic capillaries easily, particularly in inflamed areas.


  True
• Successive larger lymphatic vessels where lymph pass through from the lymph capillaries.

  Lymphatic collecting vessel
• Two large ducts in the thoracic region that returns lymph from the lymphatic collecting vessel to the venous circulation.

  1. Right lymphatic duct

  2. Thoracic duct
• It drains lymph from the right arm and the right side of the head and thorax.

  Right lymphatic duct
• It receives lymph from the rest of the body.

  Thoracic duct
• Where does the right lymphatic duct and thoracic duct empty the lymph?

  Subclavian vein on their own side of the body
• What would be the consequence of blockage of the thoracic duct?

  Edema in the areas that drain into the thoracic duct.
• True or false?

  
  

  Lymphatic vessels have thick walls and larger one have valves.

  False, they are thin walled.
• True or False?

  
  

  The lymphatic system is high-pressure and pumpless.

  False, it is low-pressure
• Three mechanisms that help transport lymph throughout the vessels.

  1. Milking action of skeletal muscles

  2. Pressure changes in the thorax during breathing

  3. Rhytmic contractions of smooth muscles in the walls of larger lymphatics.
• Cells in this place in particular help protect the body by removing foreign material such as bacteria and tumor cells from the lymphatic stream and by providing a place where lymphocytes that function in the immune response can be activated.

  Lymph nodes
• True or False?

  
  

  Lymph is transported away from the heart.

  False, it transports it back to the heart..
• It becomes a swollen gland during infection.

  Lymph nodes

  
• Agranular white blood cells in the bone marrow that mature in the lymphoid tissue.

  Lymphocytes

  
• It is kidney-shaped, about 1 centimeter long, and "buried" in the connective tissue that surrounds them.

  Lymph node
• The internal framework of lymph nodes is a network of _________________, like "cellular bleachers," that provides a place for the continually changing population of lymphocytes to "sit" as they monitor the lymphatic stream.

  Soft reticular connective tissue
• Lymphocytes arise from the1 1.____________ but then migrate to the 2.____________ and other lymphoid organs, where they reproduce further

  1. Red bone marrow

  2. Lymph nodes
• What is the benefit of having fewer efferent than afferent lymphatic vessels?

  Because the outlet is smaller than the inlet to the lymph node, the lymph fluid stops flowing briefly in the lymph node, giving macrophages and lymphocytes time to monitor the lymph for pathogens and process them.
• The outer part of the node, its 1___________, contains collections of lymphocytes called 2.____________, many of which have dark-staining centers called 3.____________.

  1. Cortex

  2. Follicles

  3. Germinal centers
• Outer part of a lymph node

  Cortex
• Collection of lymphocytes in the lymph node.

  Follicles
• It enlarges when specific B lymphocytes (the B cells) are generating daughter cells called plasma cells, which release antibodies.


  Germinal Centers
• The rest of the cortical cells are lymphocytes "in transit" that circulate continuously between the blood, lymph nodes, and lymphatic stream, performing their surveillance role.

  T cells
• Inward extensions of cortical tissue that contain both B and T cells.

  Medullary Cords
• This is where phagocytic macrophages are located in the lymph node.

  Medulla