What are the functions of the lymphatic system?
1) Draining excess interstitial fluid from tissue space
2) Draining plasma protiens from tissue space
What are the 3 routes of lymphatic circulation?
- 1) Lymphatic capillaries
- 2) Lymphatic vessels
- 3) Lymphatic trunks
What are Lymphatic capillaries?
A single layer of endothelial cells that overlap to make unidirectional valves
They pick up fluid called lymph
Lacteals are special capillaries in the small intestine that transport lipids (nutrients)
What are Lymphatic vessels?
Similar to veins with thin walls and unidirectional valves
- Afferent vessels carry lymph into lymph nodes
- Arrive = Afferent
- Efferent vessels carry lymph out of lymph nodes
- Exit = Efferent
What are Lymphatic trunks?
(Lymph passes from the vessels to the trunks)
Bronchomediastinal, jugular, subclavian, intestinal, and lumbar lymphatic trunks
The lymphatic circulation consists of 2 ducts. What are the two ducts and where they collect from?
Right lymphatic duct: smaller one that drains the right side of the head, right shoulder, right arm into the right subclavian
Thoracic duct: larger one that drains the rest of the body into the left subclavian vein
Describe the lymphatic circulation flow from start to finish?
intertstitial fluid to lymph capillaries to afferent lymphatic vessels to lymph nodes to efferent lymphatic vessels to lymphatic trunk to lymphatic ducts to subclavian vein
What are the 3 kinds of lymphocytes?
- 1. T-Lymphocytes (80%)
- 2. B-Lymphocytes (15%)
- 3. Natural Killer Lymphocytes (NK) (5%)
What are the 3 types of T-Lymphocytes and what do they do?
- (T-Lymphocytes (80%))
- Respond to intracellular antigen
- 1. Cytotoxic T-cells = kill antigen bearing cells
- 2. Helper T-cells = activate (produce) T-cells and B-cells
- 3. Memory T-cells = (intracellular antigen memory) fight off repeating antigens
What are the 2 types of B-Lymphocytes and what do they do?
- (B-Lymphocytes (15%))
- Respond to extracellular antigen
- 1. Plamsa cells = antibody (producing) secreting cells
- 2. Memory B-cells = (extracellular antigen memory cells) fight off repeating antigens
What are Natural Killer Lymphocytes?
- (Natural Killer Lymphocytes (NK) (5%))
- Can kill invading cells and tumor cells without need to respond to antigens - nonspecific defense
- Kills any antigen!
What do the Lymphocytes that stay in the red bone marrow become?
- B-Cell = antibidy mediated immunity
- NK cells = immunological surveillance
- Hemocytoblast - lymphoid stem cell - Bcell/NK cell
What do lymphocytes that exit the bone marrow become?
- T-cells = cell-mediated immunity
- Hemocytoblast - lymphoid stem cell - (thymus) mature T-cell
What are the 3 lymphatic tissues?
- 1. Mucosa Associated Lymph Tissues (MALT)
- 2. Red Bone Marrow
- 3. Tonsils
Where can you find mucosa asociated lymph tissue (MALT)?
- within the digestive and respiratory systems:
- The appendix of the large intesting
- Peyer's Patch in the small intestine
- Bronchi of the respiratory tract
What do the tonsils do?
- Defense against inhaled ot ingested microbes
- Contain tonsilar crypts that trap microbes
- Pharyngeal tonsils
- Palatine tonsils
- Lingual tonsils
What are the 3 lymphatic organs?
- 1. Lymph nodes
- 2. Thymus
- 3. Spleen
What is the structure of the lymph node and its function?
- Its a capsule (subscapular space)
- Outer cortex has B-cells
- Deep cortex has T-cells
- Medulla has B-cells
- Its function is to filter lymph (fluid) and trigger the immune response
- afferent = arrive efferent = exit
What are the 3 main lymph nodes distributions?
- 1. Cervical lymph nodes (in your neck)
- 2. Axillary lymph nodes (in your armpit)
- 3. Inguinal lymphnodes (in your pubic area)
Where is the thymus, what does it look like, and what is its function?
Located in the mediastinum above the heart
- Right and Left lobes with lobules
- Lobule cortex - growing T-cells
- Lobule medulla - mature T-cells
Secretory organ (endocrine)
Where is your spleen, what does it look like, and what is its function?
Located in the upper left quadrant (ULQ)
- Red pulp: Red blood cells plus macrophages
- White pulp: packed lymphocytes
Its function is to filter old blood cells and bacteria, stores platelets and stores iron
What are the three types of body defenses?
- 1. Nonspecific defense - external
- 2. Nonspecific defense - internal
- 3. Specific defense - immunity
What are the five nonspecific defenses first line of defense for the external?
- 1. Skin
- 2. Mucous Membranes
- 3. Tears
- 4. Saliva
- 5. Stomach acid
What are the four nonspecific defenses second line defense for the internal?
- Immunological surveillance
- 1. Antimicrobial proteins (saliva, plasma, tissue, interstitial fluid, tears?
- 2. Natural Killer (NK) Lymphocytes (find any antigen or microbes and kill them)
- 3. Phagocytes and Macrophages (neurtophils and monocytes, nonspecific eat cellular debris)
- 4. Inflammation and fever (inhibits growth and multiplication or kills with heat)
What are the two tpyes of immunity of specific defenses of body defenses?
- 1. Innate immunity - genetically specific and determined at birth (human race)
- 2. Acquired immunity - produced by exposure to antigens or by the transfer of antibodies
In acquired immunity what are the two types of immunity?
- 1. Active acquired immunity (vaccines injected or naturally get sick antigens)
- 2. Passive acquired immunity (injected when immune system is compromised like with AIDS or Naturally from mothers womb and breast milk up to 6 months of age
Immunity is provided by which two cells in response to the presence of specific antigens?
T Lymphocytes and B Lymphocytes
What are the two types of immune response?
- 1. Cell Mediated Immunity - T-Lymphocytes respond to intracellular antigens such as virus infected cells and tumor cells (inside cells)
- 2. Antibody Mediated Immunity - B Lymphocytes respond to extracellular antigens such as bacteria floating around (outside of cells)
What T Lymphocytes are involved in cell mediated immunity?
- 1. Suppressor T Cells - "brake" limit immune system activation by a single stimulus
- 2. CD4 Cells - Antigen Presenting Cells (APC) needed to activate CD4 Cells. They develop into Helper T-cells and Memory Cells
- 3. CD8 cells - Activated by contact with virus infected body cells and develop into cytotoxic T-Cells and Memory Cells
What happens to the B Lymphocytes during antibody mediated immunity?
- B Lymphocytes stay in the lymph organs and tissues
- extracellular antigen binds to B Lymphocyte receptors
- become activated and divide into plasma cells and memory cells (plasma cells secrete antibodies and antibodies destruct antigens)
Antibodies destroy antigens in what seven ways?
- 1. Neutralization - like toxins
- 2. Agglutination & Precipitation
- 3. Activation of Complement Proteins
- 4. Phagocytosis Activation
- 5. Opsonization - coats antigen and increase phagocytosis
- 6. Stimulation of Inflammation - Mast Cells and Basophils
- 7. Prevention of Antigens Adheasion
What are the two types of immune response?
- 1. Primary Response - (1st time) slow rise in antibody production. 1st small immunoglobulin M (IgM) then the big one IgG
- 2. Secondary Response - (subsequent) faster antibodies thru immunoglobulin G (IgG)