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 wayHave one way valves (like veins)Pg 338 Fig. 13.1
3 Lymph and Lymph Vessels Lymphatic capillariespermit 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 formationFilter 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. 13.4Lymph NodesPrevents local infections from spreading
6 Lymph Nodes Afferent lymph vessels Efferent lymph vessels Carry lymph to the nodeCarry lymph out of the node
7 Thymus Composed of lymphocytes – largest at puberty Source of lymphocytes before birthEspecially 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 – involutionA small lymphoid organ located in the mediastinum
8 Tonsils Masses of lymphoid tissue Located in the mouth and back of the throatFirst line of defense from exterior
9 SpleenLocated in the upper left quadrant of the abdomen – protected by the lower ribsFilters blood, destroys worn out RBC’s, and salvages iron found in hemoglobinServes as a reservoir for blood – very rich blood supply (1 pint)(largest lymphoid organ)
10 IMMMUNE SYSTEMThe 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 ImmunityIs maintained by mechanisms that attack any irritant or abnormal substance that threatens the internal environment. In other words, general protectionOften called innate immunityEx: skin, tears, mucous membranes, etc….Inflammatory response – a set of nonspecific responses that often occurs in the body.Pg 344 Fig. 13.8Innate immunity because we are born with nonspecific defenses that do not require prior exposure.
12 Inflammatory Response Mediators are releasedVascular PermeabilityInflammatory ResponseTissue Damage OccursBloodFlowIncreased # of leukocytes & mediatorsWBCsPage 344ContainedDestroyedPhagocytized
13 Nonspecific ImmunityIncludes 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 immunityPg 345 Table 13.1
14 Specific Immunity Can be either natural or artificial Natural – is not deliberate and occurs in everyday livingArtificial – 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 antigensAntigens 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 ProteinsComplement 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 diePg 347 Fig 13.10
18 IMMUNE SYSTEM CELLSPhagocytes – Neutrophils, Monocytes, and MacrophagesLymphocytes – T-lymphocytes and B-lymphocytes