1. The Lymphatic System and Immunity
Functions:
Lymph- fluid that goes between capillary blood and tissues
Lymph vessels- transport excess tissue fluid back into circulatory system
Lymph nodes- produce lymphocytes, filter out harmful bacteria
Spleen- produces lymphocytes and monocytes, blood reservoir, recycles old red cells
Thymus gland- produces t-lymphocytes

2. Lymph
Straw-colored fluid (similar to plasma)
Interstitial fluid or tissue fluid because it is in the spaces between cells
Composed of H2O, lymphocytes, some granulocytes, O2, digested nutrients, hormones, salts, CO2 and urea
(urea- a waste product of metabolism from the protein that we eat)

3. No red blood cells or protein molecules
(too large)
Carries digested food, O2 and hormones to cells
Carries wastes back to capillaries for excretion
Since the lymphatic system has no pump, skeletal muscle action squeezes lymph along
Valves prevent backward flow

4. Lymph Vessels Closely parallel veins
Located in almost all tissues and organs that have blood vessels
Tissue lymph enters small lymph vessels which drain into larger vessels called lymphatics- they flow into one of two large, main lymphatics- the thoracic duct or right lymphatic duct.

5. Lymph flows only in one direction- from body organs to the heart
1. Thoracic duct gets lymph from left side of chest, head and neck, abdominal area and lower limbs
2. Lymph then flows into the left subclavian vein
3. Then the superior vena cava
4.. Finally the heart
Lymph flows only in one direction- from body organs to the heart

6. Lymph Nodes
Tiny, oval shaped- size of pinhead to size of almond
Located alone or grouped
FUNCTION - Site for lymph production and filter for screening out harmful substances
If substance can’t be destroyed, node becomes inflamed

7. Adenoids- tonsils on upper part of the throat Palatine sides of throat
Masses of lymphatic tissue that produce lymphocytes and filter bacteria- they get smaller in size as person gets older
3 pairs:
Adenoids- tonsils on upper part of the throat
Palatine
sides of throat
Lingual
back of tongue
Say “aahhh”
Why this is helpful?

8. Sac- like mass of lymphatic tissue
Spleen
Sac- like mass of lymphatic tissue
Upper left abdominal cavity, just below diaphragm
Form lymphocytes and monocytes
Filters blood
Stores large amounts of RBCs- contracts during vigorous exercise or loss of blood, to release RBCs
Destroys or removes old or fragile RBCs
Thymus Gland
Upper, anterior thorax, above the heart
Thymus is also considered an endocrine gland

9. Immunity
The body’s ability to resist bacterial invasion and disease
Antigen- substance stimulating formation of antibodies against itself
Antibody- substance produced by the body that inactivates a specific foreign substance which has entered the body

10. Natural Immunity at birth, inherited and permanent. Includes:
Unbroken skin
Mucus and tears
Blood phagocytes
Local inflammation

11. 2. Acquired Immunity- body’s reaction to invaders
A) Passive Acquired Immunity
- Acquired artificially by injecting antibodies to protect from a specific disease
- Immediate immunity
- Lasts 3-5 weeks
- Used when someone exposed to meningitis, tetanus, infectious hepatitis
- Mother provides newborn with passive acquired immunity with breast feeding

12. B) Active Acquired Immunity- lasts longer, two types
-Natural Acquired Immunity- result of having had and recovered from a disease. For example, a child who has measles will usually not get it again - child’s body has manufactured antibodies.
- Artificial Acquired Immunity- comes from being vaccinated
Immunization- artificial resistance to a particular infection by artificial means
Antigen injected into a person to stimulate production of antibodies

13. Standard Precautions Guidelines to be used in patient care setting
Must be used when there is contact with blood, any body fluid, mucous membranes and non-intact skin
Hand washing- the single most effective way to prevent infection
1. Wash hands often
2. Wash hands immediately after removing gloves, between patient contacts
3. Use a plain (non-antimicrobial) soap
4. Wash for a minimum of 20 seconds
Gloves- worn when touching blood, body fluids, etc.
Mask, eye protection, face shield and gown- during patient care activities that may generate splashes or sprays of blood, body fluids, etc. PPE
Patient care equipment and linens- handle with care, don’t let it touch your clothing, and clean or discard appropriately.

14. Occupational Health and
Bloodborne Pathogens
Beware of needles!
Never recap used needles
Dispose of all needles and sharp objects in sharps container
Use mouthpieces, resuscitation bags, or other ventilation devices as alternative to mouth-to-mouth resuscitation
A patient who contaminates the environment should be in a private room or relatively isolated area
Opportunistic Infection- an infection caused by pathogens
Nosocomial infections – infections that occur in the hospital

15. Disorders of the Lymphatic System
Adenitis- swelling in the lymph glands
Tonsillitis
Tonsils become infected, enlarged, and cause difficulty swallowing
Surgery done in extreme cases
Lymphadenitis- enlargement of the lymph nodes, occurs when infection is present and body is attempting to fight off the infection
Hodgkin’s disease- cancer of the lymph nodes: painless swelling of lymph nodes is early symptom
RX- chemotherapy and radiation
Infectious Mononucleosis
Caused by virus
Common in young adults and children
Spread by oral contact (kissing, sharing glasses, etc.)
Symptoms- enlarged lymph nodes, fever, enlarged spleen, physical and mental fatigue, increased lymphocytes
RX-bed rest

16. Hypersensitivity
When the body’s immune system fails to protect itself again foreign material, and instead, the antibodies formed irritate certain body cells
An abnormal response to a drug or allergen
An allergen is an antigen that causes allergic responses. (Examples of allergens- ragweed, penicillin, bee stings, foods, etc.)
Anaphylaxis
Severe, sometimes fatal allergic reaction
Antigen-antibody reaction stimulates a massive secretion of histamine
Symptoms- breathing problems, headache, facial swelling, falling blood pressure, stomach cramps, and vomiting
RX- adrenaline (epinephrine)
AIDS/HIV
Acquired Immunodeficiency Syndrome
Caused by HIV or Human Immunodeficiency Virus
Affects not only homosexual males but all populations
The patient with AIDS cannot fight off cancers and most infections
Three responses to HIV infection:
AIDS
ARC (AIDS related complex)
Asymptomatic infection
Screening tests for HIV/AIDS are available

17. 1. AIDS Most severe type of HIV infection
Subject to opportunistic infections- a healthy person would fight off these infections, but a person with AIDS has a compromised immune response.
Symptoms of AIDS
Prolonged fatigue
Persistent fevers or night sweats
Persistent, unexplained cough
Thick coating in throat or on tongue
Easy bruising, unexplained bleeding
Appearance of purple lesions on mucous membranes or skin that don’t go away
Chronic diarrhea
Shortness of breath
Unexplained lymphadenopathy
Unexplained weight loss, 10 pounds or more, in less than 2 months
Incubation period: 1 month to 12 years

18. 2. AIDS-Related Complex (ARC)
Has HIV but not AIDS and develops other conditions such as:
Chronic diarrhea
Chronic lymphadenopathy
Unexplained weight loss
If life threatening opportunistic infections develop, then individual is said to have AIDS
Has HIV but no symptoms
High risk groups for AIDS- everyone who participates in risky behaviors
3. Asymptomatic infection

19. Transmission of HIV by:
Sex with someone who is HIV positive (How do you know?)
Sharing needles with infected IV drug users
At birth from infected mother
Careless handling of patient body fluids/needle sticks
HIV cannot be spread by:
Casual contact
Through air, feces, food, urine or water
Coughing, sneezing, embracing, shaking hands and sharing eating utensils
Prevention of HIV:
Avoid risky behaviors
Standard precautions