I can describe the lymphatic system. Agenda: Lymphatic System Notes Immune Response Activity Objective: I can describe the lymphatic system.

Lymphatic System Glands And Immune Response

Introduction Components Functions ________________ Vessels – _____________ Structures & organs Functions ____________________________ Transport fats from the digestive tract to the bloodstream

Spleen _______________________ Located between the stomach & diaphragm ________________________ Functions _________________ Stores blood

Spleen FG23_17B.JPG Title: The Spleen Notes: (a) The shape of the spleen roughly conforms to the shapes of adjacent organs; transverse section. (b)Visceral surface of intact spleen; major anatomical landmarks. (c)Histological appearance of the spleen. Keywords: spleen, transverse, abdominopelvic cavity, kidneys, pancreas, hilus, diaphragm, gastrosplenic ligament, stomach, liver, rib, white pulp, visceral surface, gastric area, splenic vein, splenic artery, renal area, histology, trabecular arteries, capsule, red pulp

Thymus Gland Location – ________________________________________________ The capsule divides it into 2 lobes Development Infant – conspicuous Puberty – maximum size Maturity – ____________ Function ________________________

Thymus Gland FG23_16A.JPG Title: The Thymus Notes: (a)Location of thymus on gross dissection. (b)Anatomical landmarks on thymus. (c)Low-power light micrograph of thymus. (d)Higher magnification showing structure of Hassall's corpuscles. Keywords: thymus, gross dissection, thyroid, trachea, lobe, septae, lobule, cortex, medulla, blood vessels, Hassall's corpuscles, epithelial cells, lymphocytes

Function of the Lymphatic System Defense against harmful organisms and chemicals 2 types of defense _____________ ________________ Specific defense = immunity Humoral immunity involves B cells that become plasma cells which produce antibodies that bind with specific antigens. ____________________________________________________________________________________________________________

Immune Systems Highly developed in mammals Two types of immunity: _________________________________ Adaptive immunity _________ Lymphatic System: Production & transport of leukocytes (WBC) Traps foreign invaders

Bacteria & insects inherit resistance. Vertebrates acquire immunity. Lines of defense 1st line: Non-specific barriers ______________________ “walls & moats” skin & mucous membranes 2nd line: Non-specific patrols “patrolling soldiers” _______________________ 3rd line: _____________________ specific, adaptive immunity “elite trained units” B cells & T cells Bacteria & insects inherit resistance. Vertebrates acquire immunity.

1st line: Non-specific External defense _______________ skin Traps mucous membranes, cilia, hair, earwax Elimination coughing, sneezing, urination, diarrhea __________________ stomach acid, sweat, saliva, urine Lysozyme enzyme digests bacterial cell walls tears, sweat Lining of trachea: ciliated cells & mucus secreting cells

2nd line: _________________________ bacteria attack pathogens, but don’t “remember” for next time _________________ phagocytic white blood cells macrophages, neutrophils, natural killer cells, dendritic cells Antimicrobial proteins Complement system Interferons _______________________ increase in body temp. increase capillary permeability attract macrophages/neutrophils macrophage yeast

Inflammatory response Histamine and cytokines increase blood flow to damaged site, making it look red and puffy = INFLAMMED!

Fever __________________________ system-wide response to infection activated macrophages release interleukin-1 triggers hypothalamus in brain to readjust body thermostat to raise body temperature higher temperature helps defense ________________________ _________________________ speeds up repair of tissues causes liver & spleen to store iron, reducing blood iron levels bacteria need large amounts of iron to grow Certain bacterial infections can induce an overwhelming systemic inflammatory response leading to a condition known as septic shock. Characterized by high fever and low blood pressure, septic shock is the most common cause of death in U.S. critical care units. Clearly, while local inflammation is an essential step toward healing, widespread inflammation can be devastating.

3rd line: Adaptive (active) Immunity Specific defense with memory ________________ ___________________ They respond to… _____________ B cell

B cells ________________________ Attacks foreign antigens in blood or lymph Produce specific _______________ against specific antigens Types of B cells ______________ immediate production of antibodies rapid response, short term release continued circulation in body long term immunity

T cells Involved in ________________________ Attack, learn & remember pathogens hiding in infected cells recognize antigen fragments also defend against “non-self” body cells cancer & transplant cells Types of T cells ________________ alerts rest of immune system attack infected body cells long term immunity

How do T cells know a cell is infected? Infected cells digest some pathogens MHC proteins carry pieces to cell surface foreign antigens now on cell membrane called Antigen Presenting Cell (APC) Many different WBC’s can also serve as APC tested by Helper T cells MHC proteins displaying foreign antigens infected cell TH cell WANTED T cell with antigen receptors

2 Types: ACTIVE and PASSIVE What is Immunity? 2 Types: ACTIVE and PASSIVE