Immune System
Major Functions of the Lymphatic & Immune System
Anatomy of the Lymphatic System
Humoral Response & Cellular Response
Innate/ Adaptive Immune System
Antigens and Antibodies
Cells Involved in the Immune System
Innate Defense System (Nonspecific)
Adaptive Defense System (Specific)
The First line of defense: external body membranes which consists of skin and mucosae.
Second line of defense: contain phagocytes, antimicrobial protiens and other cells that contribute to defense.
Consist of acid- acidity of skin, mucous secretions that inhibit growth which are called acid mantle.
Enzymes: lysozome of saliva, respiratory mucus, larimal fluid and enzymes in stomach that kill microorganisms
Mucin: it is a sticky mucus, lines digestive and respiratory lines
Definition: Its specific because it recognizes/ targets specific antigens. Its systemic because it is not restricted to initial site. And its memory since it mounts on stronger attack.
Phagocytes
Natural Killer Cells (NK) cells
Inflammatory response- include (magrophages, mast cells, WBCs, and inflammatory chemicals
Antimicrobial proteins (interferons and complement proteins)
Fever
Phagocytes: white blood cells that ingest and digest foreign invader
Neutrophilis: most abundant phagocytes, but die fighting, also become phagocytes, but die.
Macrophages: develop from monocytes and are chief phagocytic cells, most robust phagocytic cell
Nonphagocytic, large granular lymphocytes that police blood and lymph
Humoral (Antibody- mediated) immunity
Cellular (Cell-mediated) immunity
Antibodies, produce by lymphocytes, circulate freely in body fluids
Lymphocytes act against target infected cells.
Humoral
Antibodies, produce by lymphocytes, circulate freely in body fluids
It is blind temporarily to target cells and mark the target cell for destruction.
Active
Naturally acquired- formed in response to actual bacteria or viral infection
Artificially acquired- formed in response to vaccine of dead or attenuated pathogens
Passive
Naturally acquired- antibodies delivered to fetus via placenta or to infant with milk
Naturally acquired- antibodies delivered to fetus via placenta or to infant with milk
Cellular
T- Cells
T- cells provide defense against intracellular antigens
T cells are more complex than B cells
Some T cells directly kill cells and some release chemicals ot regulate immune response
2 Types of T Cells
CD4 cells- usually become helper T cells that can activate b cells, others become T cells & macrophages
CD8 cells- become cytotoxic T cells that can destroy cells harboring foreign antigens. They can also become memory T cells
Antigens
Antigens: substance that can mobilize adaptive defesnses and provoke an immune response
Most are large, complex molecules not really found in the body (nonself)
Characteristics
Can be a complete antigen or hapten
Contain antigenic determinants
Can be a self- antigen
Self Antigens- cells covered with variety of proteins located on surface that are not self antigenic, but can be to others
MHC Proteins- glycoproteins, codes by genes of major histocompatability complex and unique to individual
Antibodies
Also called immunoglobulins (lgs)- are proteins secreted by plasma cells
Capable of binding specifically with antigen detected by B cells
Grouped into one of 5 (lg) classes
IgM, IgA, IgD, IgG, IgE
Antibodies don't destroy antigens, they inactivate and tag them
Defesnse Mechanisms
Neutralization- Simplest, but one of most important defenses. Antibodies block specific sites on viruses or bacterial exotoxins
Agglutination: allows antigen- antibody complexes to become cross- linked into large lattice- like clumps
Precipitation: soluble molecules are cross- linked into complexes. Complexes precipitate out of solution
Complement Fixation & Activation: Main antibody defense against cellular antigas (bacteria, mismatched RB(s).
Innate Defense
Adaptive Defense
First Line of Defense: external body membranes (skin & mucosae)
Second Line of Defense: Phagocytes, antimicrobial proteins, other cells
Third line of Defense: attacks particular foreign substances.
Acid: acidity of skin, mucous secretions inhibits growth, called acid mantle
Enzymes: lysozome of saliva, respiratory mucus, lacrimal fluid and enzymes in stomach kill mircroorganisms
Mucin: sticky mucus, lines digestive/ respiratory lines
Phagocytes: white blood cells that ingest and digest foreign invaders
Neutrophilis: most abundant phagocytes, but die fighting, become phagocytic
Macrophages: develop from monocytes and are chief phagocytic cells; most robust phagocytic cell
Natural Killer Cells (NK): Nonphagocytic, large granular lymphocytes that police blood and lymph
Characteristics:
Its specific; recognizes/ targets specific antigens
It's systemic: not restricted to initial site
Its memory mounts on stronger attack
Humoral
Cellular
When B cells encounter target antigen, it provokes humoral immune response
Antibodies- circulate in blood or lymph, binding to free antigen, with adaptive mechanisms cause to destroy them
Clone cells that do not become plasma cells become memory cells
Active
Passive:
Naturally acquired- formed in response to actual bacteria or viral infection
Artificially acquired- formed in response to vaccine of dead or attenuated pathogens
Naturally acquired- antibodies delivered to fetus via placenta or to infant with milk
Naturally acquired- antibodies delivered to fetus via placenta or to infant with milk
T- Cells
2 Types of T- Cells
T- cells provide defense against intracellular antigens
T cells are more complex than B cells
Some T cells directly kill cells and some release chemicals ot regulate immune response
CD4 cells- usually become helper T cells that can activate b cells, others become T cells & macrophages
CD8 cells- become cytotoxic T cells that can destroy cells harboring foreign antigens. They can also become memory T cells
Lymphocytes
T- Cells: A type of white blood cell that is of key importance to the immune system and is at the core of adaptive immunity.
B Cells: are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system.
NK cells: large granular lymphocytes that police blood and lymph
Neutrophilis: most abundant phagocytes, but die fighting, become phagocytic on exposure
Macrophages: develop from monocytes and are chief phagocytic cells. most robust phagocytic cell
Phagocytes
Phagocytes: white blood cells that ingest & digest foreign invader
Neutrophilis: most abundant phagocytes, but die fighting, become phagocytic on exposure
Macrophages: develop from monocytes and are chief phagocytic cells. most robust phagocytic cell
Natural Killer Cells (NK)
Nonphagocytic, large granular lymphocytes that police blood and lymph
Lymph Vessels
Lymph Ducts
A lymph duct is a great lymphatic vessel that empties lymph into one of the subclavian veins.
are thin-walled vessels (tubes) structured like blood vessels, that carry lymph.
Nodes
Lymph nodes are small bean-shaped tissues found along the lymphatic vessels. The lymph nodes act as filters.
Thymus
It is a primary lymphoid organ where lymphocyte cells or T cells mature
Spleen: it fights invading germs in the blood (the spleen contains infection-fighting white blood cells) it controls the level of blood cells (white blood cells, red blood cells and platelets)