Lymphatic/Immune System
Isabel Garcia, Period:1

Major functions of the Lymphatic & Immune systems

Location of Lymphatic organs and their functions

Purpose and examples of First, Second and Third line of defense

Innate(natural) immune defenses and Adaptive(acquired) immune defenses

Humoral response and cellular response

Antigens and antibodies

Artificial vs. Naturally acquired immunity

Passive vs. Active immunity

Cells involved in the immune system and their functions

Disorders associated with the Immune system

  1. First Line of Defense (innate): external body membranes such as skin and mucous membrane
    -They have acid that inhibits growth, enzymes that kill microorganisms, mucin is sticky mucous that traps microorganism
  1. Second Line of Defense(innate): contains phagocytes, natural killer (NK) cells, inflammatory response (macrophages, mast cell, WBC), fever
    -phagocytes: WBC that ingest and digest invaders
    -neutrophils: abundant WBC but dies
    -macrohpages: develops monocytes and swallows invaders
    -NK: induces apoptosis
    -Inflammation: redness, heat, swelling, pain

^Inflammatory chemical release: chemicals released by injured tissue
Vasodilation and increased vascular permeability
Phagocyte mobilization: phagocytes enter with macrophages after

3.Third Line of Defense(adaptive): cells attack certain foreign substances, containing humoral and cellular immunity meaning B and T cells

PUS: mixture of dead neutrophils, tissue/cell, living/dead pathogens


Immunodeficiency: congenital/acquired conditions that impair function or production of immune cell


Severe combined immunodeficiency (SCID) syndrome: genetic defect with B and T cells
^Defective adenosine deaminase (ADA) enzyme can be lethal to T cells


Hodgkin’s disease: acquired immunodeficiency can cause cancer of B cells


Acquired immune deficiency syndrome (AIDS): Human immunodeficiency virus (HIV) destroys immune system by interfering Helper T. causes AIDS
^Characteristic: weight loss, night sweats, swollen lymph nodes


-can transmit through bodily fluids

Humoral Response (anit-body mediated): based on antibodies that produced by lymphocytes, their function is to bind temporarily to cells and mark them for destruction


-contains B lymphocytes
-mature in red bone marrow and thymus
-can turn to memory cells and attacks pathogens


proliferation and differentiation of B cells go to effector cell and clones plasma cells which can then turn to memory cell

Cellular Response (cell-mediated): lymphocytes that attack the target cell, directly killing while indirectly releasing chemicals to initiate inflammatory response


-contains T lymphocyte
-mature in thymus
-attack intracellular cells and can turn into memory cells
-transform into Helper T, Cytotoxic T, and Regulatory T

Antigens: substances that can mobilize adaptive defenses and provoke immune response
-Characteristics: complete or hapten antigen, contains antigentic determinants, self-antigen


A self-antigen is covered by a variety of proteins and can be antigenic to other cells
a group of self-proteins are Major Histocompatibility Complex (MHC) and allow T lymphocytes to recognize



Antibodies: also recognized as Immunoglobulins, proteins secreted by plasma cells
^capable to bind to specific antigen detected by B cell
Structure: T or Y shape with two heavy chains and two light chains


Have 5 classes:
lgM: secreted by plasma cell during primary response, activated complement, many antigen-binding sites


lgA: found in body secretions such as sweat, saliva, intestinal juice, stops pathogens from attacking epithelial cell surface


lgD: found on B cell surface, function as B cell anitgen-receptor


lgG: abundant (75-85%), main for primary&secondary response, activates complement, protects from bacteria/virus/toxins


lgE: stem ends bind to mast cells or basophils, triggers release of histamine or inflammatory response, secreted by plasma cells in skin, only found in plasma

Neutrophil: activates macrophages, kills pathogens, and communicate with macrophage and dendritic cell
Macrophage: kills pathogens and activates neutrophil
Complement Cell: kills pathogens, activates macrophage/mast/and B cells
Dendritic Cell: Activates Virgin Helper and Killer T Cell, carries antigens to help activate

Natural Killer Cells: induces apoptosis to infected cells and later kill themselves
Monocyte: eventually morph into macrophages
Eosinophil: activates neutrophil and kills parasite worms
Basophil: kills parasite worms and activates neutrophil and mast cells
Mast Cell: kills parasite worms

Virgin Killer T Cell morphs into Killer T Cell (cytotoxic): kills infected cells and remaining cells become memory killer T cell


Virgin Helper T Cell morphs into Helper T Cell: activated B cell and help assist the Killer T cell, soon morphing into memory helper T cell


Virgin B Cell morphs into B Cells: which produces antibodies that kills pathogens and any remaining antibodies is then stored as immunological memory, or morphs into memory B cell
^B cells can also morph into Plasma Cell: that produce antibodies as well

Active Innate (natural): response to actual bacteria or infections
Passive Innate (natural): antibodies delivered through placenta to fetus or milk to infant


Active Adaptive (acquired): response to vaccine of dead/attenuated pathogens
Passive Adaptive (acquired): injection of serum, gamma globulin

Passive: when antibodies are introduced into body, where it will provide protection but end when antibodies degrade


Active: B cells encounter antigens and produce specific antibodies against them

Artificial: immunity is acquired through injection of type of vaccines to body to make the body forcefully respond and build antibodies


Naturally: immunity acquired through exposure or already given before birth or exposed to antibodies

Autoimmune disease: where the immune system can not distinguish itself from foreign


Autoimmunity: production of autoantibodies and sensitized Cytotoxic T cells destroy body tissue


-treatment can be anti-inflammatory drugs, blocking cytokine action, blocking co-stimulatory molecules

Inflammation

  • 1) Inflammatory chemical release: chemicals are released into ECF such as histamine released by mast cells,


  • 2)Vasodilation and increased vascular permeability


  • 3) Phagocyte mobilization: Neutrophils flood area followed by macrophages, where complement is activated if inflammation is due to pathogens

Lymph nodes: cleanses lymph and is the site for activation and proliferation
^bunches around the neck, stomach, pelvic


Tonsils: stops germ from entering to the body from the mouth or nose


Thymus: site for T cell maturation and provides surveillance and protection


Red Bone Marrow: platelets and WBCs are created


Spleen:cleanses blood and removes bad conditioned RBC, stored monocytes/platelets/iron, site for lymphocyte activation and proliferation


Malt: prevent pathogens from penetrating mucous membrane, site for lymphocyte activation and proliferation

-Lymphatic System maintain fluid levels in the body tissue, and removes all fluids that leak from blood vessels
Absorbs digestive tract fat and removes cellular waste

-Immune System protects the body from foreign invaders and recognizes any harmful substances, while also fighting infected cells

Innate vs. Adaptive:
-Innate is nonspecific and people are born with it
^contains surface barriers like skin and mucous membrane
but also internal def. like phagocytes, NK cells, Inflammation, Antimicrobial proteins, and Fever


-Adaptive is specific and systemic, and contains memory to have stronger attacks
^contains B cells and T cells, where B is in humoral and produces antibodies while T cells is cellular and lead attacks