1. Lymphatic System

2. I. Lymphatic Network
A. Functions
1. Fluid Balance - Transport lost fluid (lymph) back to the circulatory system.
2. Defend the body against pathogens.
3. Fat absorption.

3. B. Lymphatic Capillaries
1. Microscopic dead end tubes found between cells.
(Not found in the brain, spinal cord, bone, epidermis)
2. Similar to blood capillaries.
3. Loosely Joined endothelial cells
C. Lymphatic Vessels
1. Same three layers
D. Lymph Nodes

4. E. Lymphatic Trunks & Collecting Ducts
1. Trunks – merging vessels.
2. Collecting Ducts – One duct before returning back to the heart.
a. Thoracic Duct – left side of the head, neck, thorax, left arm, entire lower body.
1. Empties into left subclavin
2. Originates from Cysterna Chyli.
b. Right Lymphatic Duct – Right side of the head, neck, right arm
1. Empties into right subclavin

5. F. Lymph Movement
1. Formation – Interstitial fluid formed by movement of blood plasma out of the capillary bed.
a. Increased interstitial fluid, increase pressure forces lymph pores open – fluid flows in.
2. Movement
a. Force of interstitial fluid entering vessel
b. Similar to veins:
1. Valves
2. Skeletal movement.

6. II. Lymphatic Organs
A. True organs
1. Lymhpoid tissue containing lymphocytes (white blood cells)
B. Lymph Node
1. Cervical – neck
2. Axillary – armpit
3. Inguinal – groin
4. Deep with in
C. Structure
1. Afferent Lymphatic Vessels – Towards.
2. Hilus- Concave margin
3. Efferent Lymphatic Vessels – Away.
4. Fibrous Capsule
5. Cortex - Outer
6. Medulla – Inner
7. Trabeculae -Extensions
8. Lymph Nodules – Main structure of lymph nodes, gathering of WBC

7. D. Node Function
1. Filter
E. Spleen
1.Largest lymphatic organ
2. Fibrous Capsule – outer, protection
3. Red Pulp – Large number of red blood cells.
4. White Pulp – Large number of white blood cells.
F. Thymus
1. Only active during immune response.
2. T cell production
3. Capsule
4. Cortex
5. Medulla
G. Tonsils
1. Two Palatine – Back of palate
2. Two Pharyngeal –Upper throat
3. Two Lingual – Base of tongue
H. Peyer’s Patches
1. Clusters located along the small intestines

8. III. Defense Mechanisms
A. Immune system has ability to recognize foreign particles (pathogens &/or toxins).
B. Major Histocompatibility Complex (MHC) – markers that can distinguish between self & non self.
C. Two types of defense.
1. Non Specific (innate)
2. Specific (adaptive)
D. Type of responses
1. Antibodies

9. E. Innate or Non Specific Mechanisms – Defends against all types of pathogens & has the same response.
1. Mechanical barriers
a. Skin
b. Mucus membranes
2. Phagocytosis – Cellular Eating
a. Monocytes
b. Neutrophils
c. Macrophages
d. Natural Killer Cells
Punches holes
in cells.
e. Swelling
Basophils
Mast cells
Eosinophils

10. 3. Chemical Mediators
a. Complement
1. 20 proteins
2. Helps enhance phagocytes
b. Interferons
1. Secreted by infected cells to stimulate neighboring cells to produce antibodies.

11. 4. Inflammation a. Edema - vasodilation
- chemical attraction of phagocytes
-Increased permeability
b. Local inflammation
c. Systematic inflammation

12. F. Specific Mechanisms – Adaptive Response
1. Ability to recognize a specific antigen or toxin.
a. Antigen recognition
b. Proliferation
2. Components of Immunity
a. Antigen – any substance that causes an immune response.
b. Antibody (Ab) (gamma globulins or immunoglobulins)– protein molecule that is produced in response to a specific antigen.
- 2 heavy chains
- 2 light chains
c. AB + Antigen = Antigen-Ab complex (inactivation)

13. 1. IgG – Most common - small 2. IgA – protection on body surfaces
d. Five Classes of Ab
1. IgG – Most common - small
2. IgA – protection on body surfaces
3. IgM – First to be produced – large
4. IgD – Antigen-antibody receptors
5. IgE – Allergies (bind to mast cells)
e. Variable region – made for specific antigens
f. constant region – same between all antibodies

14. Specific Defense

15. e. Lymphocytes – come bone marrow
1. B-cells – develop in bone marrow
a. Memory
b. Plasma – AB
2. T-cell – develop in thymus
a. Killer T cells – destroy’s infected cell
b. Helper T cells – stimulates immune system
c. Suppressor T cells – stops the body’s response
d. Memory T cells – remembers for future infections

16. 3. Cell Mediated – T cell response
a. Kills invaded & infected cells.
b. Macrophage identified an antigen, phagocytized it, & processed it.
c. Process antigen is placed on macrophage surface & is presented to the T-cells.
d. Activates the T-cells.

17. Cell Mediated Response

18. 4. Humoral Immunity – Ab Response
a. Macrophage identified an antigen, phagotized it, & processed it.
b. Process antigen is placed on macrophage surface & is presented to the B-cells.
c. Activates the B-cells with the help of Helper T-cells.
d. Grows & multiple into memory B cells (immunization) & Plasma cells (Ab).
e. AB production takes 3-5 days, peaks in 3 weeks.
f. AB binds to antigen surface forming the antigen-Ab complex (inactivated).
g. Labeled for destruction for natural killer cells.

19. Humoral Response

20. Effect of Antibodies

21. Antibody Production

22. Specific response review

23. G. Allergic Response – Type of humoral resposne.
1. IgE Ab is released into blood in response to the allergen.
2. Comes into contact with the mast cell (concentrated in skin & mucus layer).
3.Mast cell stores histamines.
4. IgE + Mast cell = release of histamine (causes inflammation.
Ex. Hives & asthma
Systemic anaphylaxis
5. Immediate hypersensitivities – hay fever, asthma
6. Delayed hypersensitivities – poison ivy, soaps, cosmetics

24. H. Acquired Immunity
1. Persons ability to mount a defense.
2. Two Types
1. Naturally acquired
a. Active – develop after exposure.
ex- chicken pox, flu, measles.
b. passive – passed from 1 person to another.
ex- Polio, rubella – mother to baby by placenta or breast milk.
2. Artifically Acquired - Vaccine
Killed or weaken virus that causes an immune response with out the symptoms.
a. Active – Lifelong
ex. polio, measles
b. Passive – Short term
ex- rabies, hepatitis, tetanus, snake venoms.

25. Immunity

26. IV. Homeostasis 1. Recycling valuable fluids. 2
IV. Homeostasis 1. Recycling valuable fluids. 2. Defense against diseases.

28. V. Immunodefiency
1. WBC are reduced which reduces the body’s ability to defend itself.
a. Attacked by pathogens.
b. Low level production. Ex
1. SCID – Severe Combined Immundeficiency
a. Born without the ability to produce active B & T cells.
b. Treatment – bone marrow transplant.
2. AIDS
a. Caused by HIV virus
b. Destroy’s the helper T cells – body never knows it is getting invaded by other pathogens.
c. ID in US – 1981
3. Hodgkins – Cancer
a. large multinucleated cell in affected lymphoid tissue
b & over 50 yrs old.