Immune system

icer215's version from 2016-08-18 03:31


Question Answer
Immune system protects us from and causes disease. Rheumatoid arthritis is an example where the immune system attacks the body (at the joints).
Cells and their Basic FunctionsThe cells of the immune system are the leukocytes (white blood cells).
Bone marrowpluripotent stem cells form either 1) myeloid precursors (end up as phagocytes, basophils or eosinophils) or 2) lymphoid precursors (end up as lymphocytes)
Myeloid stem cells make red blood cells, megakaryocytes (form platelets), monocytes (become macrophages and dendritic cells) or polymorphonuclear leukocytes (eosinophils, basophils and neutrophils) and mast cells.
Lymphoid stem cellslymphoid stem cells, form T cells, B cells and natural killer cells.
T-lymphocytes (from the Thymus), cytotoxic T cells kill infected cells via apoptosis, and helper T cells signal for macrophages, T and B cells, both recognize antigens on infected cells.
B-lymphocytes(from the Bone Marrow) plasma cells (secrete antibody when exposed to antigen), and memory cells (waiting for the same antigen to attack again in the future).
Natural killer cells(increased count as a result of massage) kill cancer/abnormal cells.


Question Answer
Phagocytes(macrophages, dendritic cells and neutrophils) eat foreign invaders, clean debris and dead cells .
Macrophages and dendritic cells present antigens.
Eosinophilskill multicellular parasites.
Basophilsfight ticks (and other ectoparasites) and help regulate T cells, as well as being involved with allergic inflammation.
Mast cellsare also involved with allergies, they are the attacker in rheumatoid arthritis and multiple sclerosis, the benefit of mast cells is they activate the bodies immune response when under bacterial attack.
Innate/Nonspecific ImmunityThe mast cells cause inflammation and alert the body to attack, the neutrophils kill invaders, the macrophages and dendritic cells both kill and present antigens of invaders (for T and B lymphocytes to memorize).
T Lymphocytes (Specific Immunity) recognize antigens, cytotoxic T cells kill the invading cells via apoptosis, helper T cells call for back up by signaling for macrophages, T and B cells to come kill the invading cells.
B Lymphocytes, Plasma Cells (Specific Immunity)The B lymphocytes alert the immune system using antibodies. Plasma cells secrete antibodies when exposed to an antigen.


Question Answer
Lymphoid organsCrucial in the immune system.Thymus gland.Considered primary lymphoid organs.Promote production of immune cells
Tissues associated with the immune system are the thymus tissues (T cell mature), the bone marrow (B cells mature), the lymph nodes and the spleen tissues.
Bone MarrowBlood cells are made in the bone marrow, B lymphocytes mature here (thus the name).
Spleen removes old red blood cells from circulation, also removes platelets allows white blood cells to hang out and grow. The fetal spleen makes blood cells. Removes bad stuff from the blood.
ThymusT cells mature in the thymus (thus the name).
Lymph NodesSmall oval structures. Found at intervals along the lymphatic system. In armpits, groin, chest, abdomen, and so on (locate green circles in the diagram below). Receive the fluid from lymphatic vessels. Filter and diffuse back into the circulation through veins
Basic Aspects of Innate Immunity and Inflammatory ResponseInnate immunity means non-specific immunity. The first time a pathogen enters the body it only has innate immunity and inflammation to kill the pathogen. The next time it knows the tricks, habits and appearance of the pathogen and the body will have specific immunity as well as innate immunity and inflammatory response.
Skinis part of innate immunity; the thick oily kerainized outer layer is like a rain jacket, the bacteria and friends (flora) that live on our skin keep other stuff from having room to live there.
Mucus membranes are part of innate immunity; the mucus traps pathogens physically preventing them from moving like a fly trap, cilia they "bounces" the pathogen out of the body.


Question Answer
White blood cells(the phagocytes anyways) are part of innate immunity; the swallow and kill pathogens
Natural killer cellsare part of the innate immunity; I'm not going to explain what they do the pathogens
Antimicrobial proteinslyse (slice up) bacteria, interfere with virus replication, and complement (punch a hole in) pathogen membranes. In summary if attached by a bacteria, a virus and a fungus, the antimicrobial proteins slice up the bacteria, pierce the fungus and cock block the virus.
Fever and Inflammation are part of innate immunity; heat helps white blood cells function better, inflammation causes more white blood cells to go to the site of infection by sending out chemical signals and making capillaries more permeable.
Antigens(lock) and antibodies(key)are used for specific immunity, also called adaptive immunity.
Antigen presenting cells kill invaders then display their antigen on their surface, like a warrior displaying a decapitated head on a spike.


Question Answer
Antigensare recognized by T and B cells. The cyctotoxic T cells see the antigen and go kill the invaders with that antigen.
Helper T cells call for help when they see an antigen. They call macrophages, cytotoxic T and B cells.
B cellsproduce antibodies, which not only make pathogens easier to find but also, kill pathogen by putting holes in their membranes (complement activation), making them easier to eat (opsonization) and making pathogens unable to sick to a host cell (neutralization) keeping them in circulation where white blood cells are hunting them.
Structure of Antibody MoleculeAntibodies are Y shaped (contain two light chains and 2 heavy chains linked together by disulfide bonds, the tips of the fork (called the hypervariable region) bind to a specific antigen.
Mechanism of Stimulation by Antigenvaries based on if the pathogen is extracellular or intracellular. An extacellular pathogen will be eaten by a macrophage, pieces of it get displayed on the surface of the macrophage, helper T cells call the alarm when they see the pieces, allowing the macrophages to destroy the pathogen and B cells to make antibodies that can also destroy the pathogen. An intracellular pathogen invades a host cell, pieces of the pathogen end up on the cell membrane, cytotoxic T cells recognize the pieces (antigens) and cause the infected cell to self-destruct.