1. The Lymphatic & Immune Systems
Chapter 17

2. Lymphatic System Page 298 Supplements the circulatory system
Composed of lymph, lymph nodes, lymph vessels, the spleen, the thymus gland, lacteals (lymphoid tissue in the intestinal tract), & the tonsils
Unlike the circulatory system there is no muscular pump or heart
Peyer’s patches

3. Functions of the Lymphatic System
Page 299
Functions of the Lymphatic System
Acts as intermediary between blood & tissue
Transports excess filtered tissue fluid
Produces lymphocytes to destroy harmful bacteria
Lacteals absorb fat & fat soluble vitamins.
Spleen produces lymphocytes & monocytes
Thymus gland produces T lymphocytes

4. Interstitial Fluid (intercellular)
Page 299
Interstitial Fluid (intercellular)
Straw colored; No red blood cells or proteins (similar in composition to blood plasma)
Called lymph when fluid enters lymph capillaries
Moves with assistance of skeletal tissue contraction, breathing movements, & valves
Some of the fluid may not get reabsorbed, which results in swelling of the tissue & the resulting condition is known as edema.
Composed of water, lymphocytes, some granulocytes, digested nutrients, hormones, salts, carbon dioxide, & urea.

5. Lymph Vessels Page 299 Lymph vessels = Closely parallel the veins
Lymph capillaries begin as blind-ended tubes. Smaller vessels unite to form larger vessels & these in turn, join forming larger & larger lymph vessels called lymphatics. The two main lymphatic vessels are:
Right lymphatic duct receives from the right side of the arm, right side of the head, & upper limbs. Drains into the right subclavian vein.
Left lymphatic duct (thoracic duct) receives from the left side of the chest, head, neck, abdominal area, & lower limbs. Drains into the left subclavian vein.
Flows in only one direction from organs to the heart (not a circuit)
Both subclavian veins pour into the superior vena cava

6. Page 300
Lymph Nodes
Small structures located alone or grouped in various places along the lymph vessels throughout the body
Trabeculae – capsules of fibrous connective tissue that extends into the node; they divide the node into a series of compartments that contain lymphatic sinuses & lymphatic tissue.
Afferent lymphatic vessels
When germinal centers are stimulated, the immune response is activated
Swelling in the lymph glands is known as lymphadenitis

7. Pages 300 – 301
Tonsils
Masses of lymphatic tissue that produce lymphocytes & filter out bacteria
Three pairs of tonsils
Palatine – located on the sides of the soft palate
Adenoids – upper part of the throat
Lingual – found at the back of the tongue
Tonsillitis – when tonsils become infected & enlarged, this can cause difficulty in swallowing, severe sore throat, elevated temperature, & chills

8. Pharyngeal is also known as the adenoids

9. Page 301
Spleen
Saclike mass of lymphatic tissue; Forms lymphocytes & monocytes; Filters out bacteria; & Stores red blood cells
Located: upper left of the abdomen beneath the diaphragm
During excessive bleeding or vigorous exercise, the spleen, contracts, forcing the stored RBCs into circulation. It also destroys & removes old or fragile RBCs, & forms erythrocytes in the embryo.

10. Pharyngeal is also known as the adenoids

11. Page 302
Thymus Gland
Located: in the upper anterior part of the thorax, above the heart
Produces & matures lymphocytes (T lymphocytes)
It is also an endocrine gland that secretes a hormone called thymosin

12. Pharyngeal is also known as the adenoids

13. Peyer’s Patches Page 302 Located: in the walls of the small intestines
Produce macrophages
Macrophages destroy bacteria & prevent bacteria from penetrating the walls of the small intestines

14. Lacteals Page 302 Specialized lymph capillaries
Found in villi of the small intestine
Absorb digested fat & fat-soluble vitamins

15. Effects of Aging Page 303 SB Decline in immune function
Increased risk of infection
Decreased ability to fight disease
Slowed wound healing

16. Disorders of the Lymph System
Page 302
Disorders of the Lymph System
Lymphadema – swelling of the tissues due to an abnormal collection of lymph. It is caused by damage to the lymph system that prevents lymph from draining properly.
Lymphoma – a tumor of the lymphatic tissue, usually malignant.
Hodgkin’s disease – distinguished from other lymphomas by the presence of large cancerous lymphocytes known as Reed-Strenberg cells.
Infectious mononucleosis – disease caused by the Epstein-Barr virus.

17. Function of Immune System
Page 303
Function of Immune System
Protect body from harmful substances such as:
Pathogens (disease producing agents)
Allergens
Toxins
Malignant cells

18. Page 303
Immunity
Immunity = The body’s ability to resist infections from pathogens, foreign substances, & toxic chemicals
Individuals differ in their ability to resist infection & an individuals resistance varies at different times.
Humoral immunity: B cells & antibodies
Cellular immunity: T cells

19. Normal Defense Mechanisms
Page 303
Normal Defense Mechanisms
The individual’s immune system serves as the normal defense mechanism against the transmission of infectious agents
Ability to recognize foreign agent (antigen)
Antibodies protect body against antigens
Specific & nonspecific immune defenses

20. Antigen-Antibody Reaction
Page 303
Antigen-Antibody Reaction
Also known as immune reaction & involves binding antigens to antibodies
An antigen is identified as any substance that the bod regards as being foreign
Antibody is a disease-fighting protein

21. Nonspecific Immune Defense
Page 303
Nonspecific Immune Defense
Protects from all microorganisms & is not dependent on prior antigen exposure these include:
Skin & normal flora serve as a physical barrier against infectious agents
Mucous membranes entrap infectious agents & contain antibodies, lactoferrin, & lysozyme, which inhibit bacteria growth.
Sneezing, coughing, & tearing reflexes physically expel mucus & microorganisms with force.

22. Nonspecific Immune Defense (Cont’d)
Page 304
Nonspecific Immune Defense (Cont’d)
Elimination & acidic environment prevent microbial growth of pathogenic organism.
Inflammation is the nonspecific response to cellular injury.
Immunoglobulins: IgG, IgM, IgD, IgE, IgA – a class of specialized proteins that function as antibodies.

23. Specific Immune Defense
Page 304
Specific Immune Defense
Lymphocytes are precursors of many cells involved in immune response
B cells – lymphocytes found in the lymph node, spleen, & other lymphoid tissue when they replicate.
Plasma cells – formed by B cells & produce huge quantities of the same antibody or immunoglobulin.
Helper T cells – stimulates the production of killer T cells & more B cells to fight the invading pathogens.

24. Specific Immune Defense (Cont’d)
Page 304
Specific Immune Defense (Cont’d)
Killer T cells – kill virus-invaded body cells & cancerous body cells
Suppressor T cells – slow down the activities of B & T cells once an infection has been controlled.
Memory cells – descendants of activated T & B cells produced during an initial immune response
Macrophages – engulf & digest the antigens.

25. Chemical & Immune Response
Page 304
Chemical & Immune Response
Lymphokines & interleukins are released by lymphocytes & macrophages as a part of the immune response
Activated macrophages release cytokines
Interferon is produced by cells that have been infected by a virus; binds to surroundings helping to protect them from the virus
TNF kills tumor cells; attracts macrophages
Complements cascade cause breakdown (lysis) of microorganisms & enhances inflammatory process
Lymphokine are released by the sensitized lymphocytes on contact with specific antigens that help cellular immunity by stimulating activities of monocytes & macorphages

27. Natural & Acquired Immunities
Pages 305 – 307
Natural & Acquired Immunities
Natural immunity = Immunity we are born with, it is inherited & permanent
Acquired
Natural – reaction that occurs as a result of exposure to invaders e.g., measles as a child
Artificial – inculcation with a vaccine, antigen or toxoid e.g., tetanus injection
Passive acquired immunity = Acquired artificially by injecting antibodies, temporary protection, lasts only 3–5 weeks

28. Page 307
Immunization
Process of increasing an individual’s resistance to an infection by artificial means
Immunization charts
Ages 0–6
Ages 7–18
Adult
Catch-up
The charts are on pages

29. Page 307 & 313
Autoimmunity
Autoimmune disorder = when the body mistakenly targets the normal cells, tissues, & organs of a person’s own body
Can be triggered by multiple causes
Causes can be genetic familial predisposition, viral, or even sunlight (which can act as a trigger for lupus)

30. Autoimmune Disorders Page ? Addison’s disease
Hypothyroidism/hyperthyroidism
Lupus/systemic lupus erythematosus
Multiple sclerosis
Myasthenia gravis
Pernicious anemia
Psoriasis
Rheumatoid arthritis
Scleroderma
Type I diabetes mellitus
Ulcerative colitis/Crohn’s disease

31. Hypersensitivity Pages 313 – 314
Hypersensitivity = occurs when the body’s immune system fails to protect itself against foreign material
Allergens = an antigen that causes allergic response
Anaphylaxis (anaphylactic shock) = an even more severe & sometimes fatal allergic reaction
People with such hypersensitivity should wear Medic-alert tags to alert medical professionals in the event of an emergency.
Anaphylaxis = breathing problems, headache, facial swelling, falling BP, stomach cramps, & vomiting. If proper care is not administered immediately death my occur in minutes.

32. Page 314
HIV/AIDS
Human immunodeficiency virus (HIV) causes AIDS; it destroys the body’s T4 lymphocytes which allows for Opportunistic infections
Three outcomes from infection with HIV
Asymptomatic infection
AIDS-related complex (ARC)
AIDS
A – Acquired = The disease is not inherited
I – Immune = Refers to the body’s natural defenses against cancers, disease, and infections
D – Deficiency = Lacks cellular immunity
S – Syndrome = Involves the set of diseases or conditions that are present to signal the diagnosis

33. HIV/AIDS Statistics Pages 314 – 315
50,000 people in the US infected annually
2.1 million people in the US living with AIDS

34. Transmission of HIV/AIDS
Page 315
Transmission of HIV/AIDS
Sexual contact
Sharing hypodermic needles
From infected mother to baby (in utero) at birth, through breast feeding
Transfusion of contaminated blood, semen donations, skin grafts/organ transplants from & infected person
Scientists have found no evidence that HIV is spread through sweat, tears, urine, or feces.
The virus is fragile & doesn’t live outside the body long

35. Screening Tests for HIV/AIDS
Page 315
Screening Tests for HIV/AIDS
ELISA
Western blot assay
Rapid test
Home sampling – FDA approved test kit

36. Symptoms of HIV/AIDS Pages 315 – 316
Flu-like symptoms (lack of energy, cough, frequent fevers), weight loss, night sweats, shortness of breath, some mental impairment
Blotchy red rash on the upper torso
Enlarged lymph glands
Opportunistic conditions
Bacterial infections
Cancers
Parasitic infections
Fungal infections
Viral infections
Bacterial infections such as tuberculosis, which is the most common infection
Cancers espcially Kaposi’s sarcoma, cervical cancer, or lymphomas

37. Treatment of HIV/AIDS Pages 316 – 317 No cure for AIDS
Drugs used in combination to control the virus
Combinations of drugs extend life of infected individuals

38. Preventing Transmission of HIV/AIDS
Page 317
Preventing Transmission of HIV/AIDS
Education & training
Limit sexual contacts
Use of condoms
Do not share needles
Clean up soiled materials
Cover wounds
Tell partner if you have HIV/AIDS
Standard precautions used by all health care professionals