IMMUNE SYSTEM Anatomy & Physiology

FUNCTION Protect body from infection from: pathogens bacteria toxins viral parasite fungi

DEFENSE..<clap clap> DEFENSE First line- skin/mucous membranes & mucus Provides a physical barrier preventing access into body Physiological variables: pH and temperature Chemical defense: nitric oxide; enzymes https://www.youtube.com/watch?v=zQGOcOUBi6s

IMMUNE SYSTEM: 2 BRANCHES Innate (response to non “self” cells Adaptive (response to previously recognized foreigner)

CELLS! Neutrophil- 60% WBC, patrol tissue, large numbers when infected short lives (die after digesting bacteria) dead crud = pus Macrophage- large, found in organs; made in bone marrrow (monocytes); long lived; innate Phagocytic and release cytokines (enhance immune response) phagocytosis : release histamine (cells under attack) neutrophil comes

MORE CELLS! Basophil - release histamine (dilate blood vessels) cause redness, swelling, heat, fever IE: INFLAMMATION

Cells…known as: Lymphocytes Lymphocyte- produce antibodies; T & B cells, circulate in blood and lymph when mature B lymphocyte: many diff types, plamsa cells(make lots of antibodies); memory cells(divide fast as soon as antigen is present again) T lymphocytes: secrete cytokines; help B divide and kill cells and memorize antigen

ANTIBODIES Antibodies (immunoglobin) (IG) IgG: most abundant; in blood/lymph; can cross placenta IgA: found in teras; milk, blood; lymph IgM: first to be secreted, blood/lymph; cant cross placenta IgD: blood, lymph, B cells IgE: allergies

Specific vs. non-specific Nonspecific immunity: initial immune reaction against foreign antigens via nonspecific antibodies and immune cells Specific immunity involves production of antibodies against a particular antigen

LYMPHATIC SYSTEM Anatomy & Physiology

Consists of: Lymphatic vessels Lymphatic tissue/organs Organs include: Lymph nodes Spleen Thymus Tonsils

FUNCTIONS Return interstitial fluid/proteins to blood Transport dietary fats to adipose tissue Protect against cancer/infection Eliminate abnormal (sick/old/cancerous), cells and pathogens

ORGANS Lymph nodes: oval, bean shaped; scattered throughout body can be deep or superficial FUNCTIONS: filter lymph trap foreign material/debris/bad cells; produce lymphocytes

ORGANS Spleen: largest lymph organ FUNCTIONS: A. Red pulp: contains circulating blood, filter and store blood site for immune surveillance/response easily ruptured from trauma regulating blood; site of fetal erythrocyte production store approx. 1L of blood (released during emergency) B. White pulp: similar to lymph; has immune cells

ORGANS Thymus Tonsils: multiple groups of large lymph vessels differentiation and maturation of T cells secretes hormones critical in childhood shrinks as you age Tonsils: multiple groups of large lymph vessels Trap and destroy bacteria w/ immune cells Palatine tonsil: most infected Pharyngeal Lingual:  base of tongue

LYMPH FLOW Approx. 3 L of lymph is made Flow is facilitated by muscle/respiratory pump and valves of smooth muscle