1. Chapter 15: The Lymphatic System and Immunity

2. The Lymphatic System System of tissues and vessels
Scattered throughout the body
Services almost all regions

3. Functions of the Lymphatic System
Fluid balance
Lymph fluid
Protection from infection
lymphocytes
Absorption of fats

4. The lymphatic system in relation to the cardiovascular system
The lymphatic system in relation to the cardiovascular system. Lymphatic vessels pick up fluid in the tissues and return it to the blood in vessels near the heart.  

5. Pathway of lymphatic drainage in the tissues.

6. Lymphatic Circulation
One-way system
Begins in tissues
Ends in bloodstream

7. Lymphatic Capillaries
Capillary walls (endothelium) are flattened epithelial cells
More permeable than blood capillaries
Overlapping cells form one-way valves
Arise blindly (closed at one end)
Lacteals absorb digested fats
Fats are transported into lymphatic vessels until lymph is added to the blood

8. Lymphatic Vessels Thin walled, delicate Have a beaded appearance
Superficial sets
Deep sets
Nodes

9. Right Lymphatic Duct Short vessel
Receives lymph that comes from superior right quadrant
Right side of head, neck, thorax
Empties into right subclavian vein

10. Thoracic Duct Left lymphatic duct Larger of two vessels
Receives lymph from all parts of the body except those above the diaphragm on right side
Cisterna chyli
First portion
Storage pouch

11. Vessels and nodes of the lymphatic system
Vessels and nodes of the lymphatic system. (A) Lymph nodes and vessels of the head. (B) Drainage of right lymphatic duct and thoracic duct into subclavian veins.

12. Movement of Lymph
Segments of vessels located between the valves contract rhythmically
Skeletal muscles compress vessels

13. Lymphoid Tissue Distributed throughout the body
Makes up specialized organs of lymphatic system

14. Lymph Nodes Grouping Cervical nodes Axillary nodes Mesenteric nodes
Structure
Fibrous connective tissue capsule from which partitions (trabeculae) extend into nodes substance
Afferent lymphatic vessel
Hilum
Sinuses
Cords
Nodules
Medulla
Efferent lymphatic vessel
Grouping
Cervical nodes
Axillary nodes
Mesenteric nodes
Inguinal nodes

15. The Spleen Cleanses blood Filtration Phagocytosis
Destroys old red blood cells
Produces red blood cells before birth
Is reservoir for blood

16. Location of lymph tissue.

17. The Thymus Plays key role in early immune system development
Produces thymosin
Develops T lymphocyte cells
Promotes lymphocyte growth
Promotes lymphoid tissue activity
Shrinks after puberty

18. The Tonsils Remove contaminants and trap pathogens Palatine tonsils
Pharyngeal tonsil (adenoids)
Lingual tonsils

19. Location of the tonsils.

20. Other Lymphoid Tissue Appendix
Mucosal-associated lymphoid tissue (MALT)-prevents microorganisms from invading deeper tissues
Peyer patches
Gut-associated lymphoid tissue (GALT)
Includes peyer patches, tonsils and appendix

21. The Reticuloendothelial System
Cells responsible for destroying worn-out blood cells, bacteria, cancer cells and other harmful foreign substances
Monocytes
Develop into macrophages
Macrophages
Kupffer cells
Located in the liver sinusoids
Dust cells
Ingest solid particles that enter the lungs

22. Body Defenses Against Disease
Types of general body defenses against disease
Nonspecific defenses
Effective against any harmful agent
Specific defenses
Effective against a certain agent only

23. Nonspecific Defenses Successive lines of defense Simple outer barriers
More complicated responses
Immunity (ultimate defense mechanism)

24. Chemical and Mechanical Barriers
Skin
Mucous membranes
**Cilia
Body secretions
Tears
Perspiration
Saliva
Digestive juices
Reflexes
Sneezing
Coughing
Vomiting
Diarrhea

25. Phagocytosis White blood cells take in and destroy waste and foreign
material
Neutrophils
Macrophages

26. Natural Killer Cells Type of lymphocyte
Can recognize body cells with abnormal membranes
Found in lymph nodes, spleen, bone marrow, blood
Secrete protein that breaks down cell membrane

27. Inflammation Infection is inflammation caused by pathogens
**Inflammatory reaction
Heat, redness, swelling, pain
Cells release histamine
Leukocytes enter tissue
Granulocytes, macrophages, mast cells
Leukocytes and plasma produce inflammatory exudate
Pus is produced
Lymph nodes enlarge

28. Fever
As phagocytes work, they release substances that raise body temperature
Stimulates phagocytes
Increases metabolism
Decreases some organisms’ ability to multiply

29. Interferon
Group of substances that prevent nearby cells from producing more virus
IFN a (alpha)
IFN b (beta)
IFN g (gamma)
Also acts nonspecifically on immune system cells

30. Specific Defenses—Immunity
Power to overcome a specific disease agent
Innate immunity
Inherited in genes
Adaptive immunity
Develops after birth
Acquired naturally or artificially
Active or passive

31. Types of
immunity

32. Innate Immunity Differences in physical constitution Species immunity
Individual immunity

33. Adaptive Immunity Develops in a person During lifetime
From encounters with specific harmful agents

34. Antigens Foreign substances that Enter body
Induce immune response of certain lymphocytes
T cells
B cells

35. T Cells Originate in stem cells in bone marrow
Change to T cells in thymus
*Become sensitized to specific antigens
Produce cell-mediated immunity
Cytoxic T cells
Helper T cells
Regulatory T cells
Prevents overactivity
Memory T cells
Macrophages
Phagocytic
Insert fragments of the foreign antigen into their plasma membrane, antigen then displayued on the macrophages surface in combination with antigens that a T cell can recognize as belonging to the self

36. B Cells and Antibodies
Antibody (Ab) also known as immunoglobulin (Ig) is substance produced in response to antigen
Manufactured by B cells (B lymphocytes)
Must mature in fetal liver or in lymphoid tissue
Provides humoral immunity
Contained in gamma globulin fraction of blood plasma

37. Activation of B cells. The B cell combines with a specific antigen
Activation of B cells. The B cell combines with a specific antigen. The cell divides to form plasma cells, which produce antibodies. Some of the cells develop into memory cells, which protect against reinfection.  

38. The Antigen–Antibody Reaction
Effects
Prevents attachment of pathogens
Causes clumping of antigen
Neutralizes toxins
Aids phagocytosis
Activates NK cells
Activates complement
Group of enzymes
Acts non-specifically
Promotes phagocytosis
Destroys cells
Promotes inflammation

39. Naturally Adaptive Immunity
Immunity acquired through contact with a specific
disease organism
Active immunity
Passive immunity

40. Figure 15-7 Nonspecific immunity.

41. Artificial Adaptive Immunity
Vaccination (immunization) can cause a person’s
immune system to manufacture antibodies
Preventive measure
Risk of side effects

42. Types of Vaccines Live Attenuated Toxoid Killed by heat or chemicals
Antigenic component
Genetically engineered

43. Boosters Active immunity does not always last a lifetime
Repeated inoculations (booster shots) help maintain high titer of antibodies in the blood
Number and timing varies with vaccines

44. Passive Immunity
Acquired by administration of immune serum (antiserum)
Short-lived immunity
Used in emergencies
Often derived from animals
May cause sensitivity reaction