1. The Lymphatic System and Immunity
Chapter 13

2. Lymph and Lymph Vessels
a specialized fluid formed in the tissue spaces that is transported by of specialized lymphatic vessels to eventually reenter the circulatory system.
Movement of lymph is one way
Have one way valves (like veins)
Pg 338 Fig. 13.1

3. Lymph and Lymph Vessels
Lymphatic capillaries
permit excess tissue fluid and some other substances such as dissolved protein molecules to the leave the tissue spaces.
Pg 339 Fig 13.2

4. Lymph Nodes Filter lymph before reentering blood
2 jobs – defense and white blood cell formation
Filter out bacteria and other abnormal cells by phagocytosis
(vary in size from pin head to lima bean) – most are located in clusters

5. Prevents local infections from spreading
Pg 341 – Fig. 13.4
Lymph Nodes
Prevents local infections from spreading

6. Lymph Nodes Afferent lymph vessels Efferent lymph vessels
Carry lymph to the node
Carry lymph out of the node

7. Thymus Composed of lymphocytes – largest at puberty
Source of lymphocytes before birth
Especially important in the maturation or development, of specialized T lymphocytes (T cells).
Thymus completes most of its work early in childhood and is replaced largely by fat and connective tissue – involution
A small lymphoid organ located in the mediastinum

8. Tonsils Masses of lymphoid tissue
Located in the mouth and back of the throat
First line of defense from exterior

9. Spleen
Located in the upper left quadrant of the abdomen – protected by the lower ribs
Filters blood, destroys worn out RBC’s, and salvages iron found in hemoglobin
Serves as a reservoir for blood – very rich blood supply (1 pint)
(largest lymphoid organ)

10. IMMMUNE SYSTEM
The body’s defense mechanisms protect us from disease- causing microorganisms, from foreign tissue cells that may have been transplanted into our bodies, and from our own cell when they have turned malignant or cancerous.

11. Nonspecific Immunity
Is maintained by mechanisms that attack any irritant or abnormal substance that threatens the internal environment. In other words, general protection
Often called innate immunity
Ex: skin, tears, mucous membranes, etc….
Inflammatory response – a set of nonspecific responses that often occurs in the body.
Pg 344 Fig. 13.8
Innate immunity because we are born with nonspecific defenses that do not require prior exposure.

12. Inflammatory Response
Mediators are released
Vascular Permeability
Inflammatory Response
Tissue Damage Occurs
Blood
Flow
Increased # of leukocytes & mediators
WBCs
Page 344
Contained
Destroyed
Phagocytized

13. Nonspecific Immunity
Includes protective mechanisms that confer very specific protection against certain types of invaders.
Involves the memory and ability to recognize and respond to certain harmful substances or bacteria – called adaptive immunity
Pg 345 Table 13.1

14. Specific Immunity Can be either natural or artificial
Natural – is not deliberate and occurs in everyday living
Artificial – is called immunization and is deliberate exposure of the body to a potentially harmful agent.

15. Specific Immunity Active Passive
When an individuals own immune system responds to a harmful agent, regardless of whether that agent was naturally or artificially encountered.
When immunity to a disease that has developed in another individual or animal is transferred to an individual who was not previously immune.
Natural and artificial can be active or passive

16. IMMUNE SYSTEM MOLECULES
Antibodies – protein compounds that are normally present in the body.
Have combining sites and combine with antigens
Antigens are often protein molecules imbedded in the surface membranes of invading or diseased cells.
In general, antibodies produce immunity by changing the antigens so that they cannot harm the body.
Pg 346 Fig 13.9

17. IMMUNE SYSTEM MOLECULES
Complement Proteins
Complement is that name used to describe a group of protein enzymes normally present in an inactive state in the blood.
Complement cascade – basically drill holes in foreign cells causing them to die
Pg 347 Fig 13.10

18. IMMUNE SYSTEM CELLS
Phagocytes – Neutrophils, Monocytes, and Macrophages
Lymphocytes – T-lymphocytes and B-lymphocytes