The Immune and Lymphatic Systems

• Anaphylactic shock is a life-threatening condition from seemingly harmless items or foods
• The immune system safeguards against viruses, bacteria, fungi, parasites, and toxins

Innate Immunity

• It recognizes microbial invaders swiftly

Adaptive Immunity

• Receptors are produced on the surface of white blood cells and then bind to a foreign antigen
• Lymphocytes are stimulated to increase in number, which increases the response to specific antigens
• Immunological memory is a result of this process

The Lymphatic system

• Lymphatic vessels and organs form this system
• Excess fluid is taken up and returned to the bloodstream by lymphatic capillaries

Lacteals

• Lacteals absorb fats as lipoproteins
• They then transport the fats to the bloodstream

Lymphocytes

• These are produced, maintained and distributed by the lymphatic system
• They resist infection and disease by responding to invading pathogens like bacteria or viruses
• Lymphocytes also respond to abnormal body cells like cancer cells, and to foreign proteins like toxins

Lymphatic Vessels

• Lymphatic capillaries begin here as a One-way system
• They are tiny and closed-ended vessels throughout the body
• Excess tissue fluid (interstitial) is taken up

Lymph

• Lymph is the fluid located within lymphatic capillaries
• Lymph flows from a capillary to larger vessels and finally to a lymphatic duct
• The lymphatic duct returns lymph to a subclavian vein
• One-way valves prevent backflow

Lymphoid Organs

• Red bone marrow is the site of origin for all blood cells, and maturation for B cells
• The thymus gland is between the trachea and sternum in the upper thoracic cavity
• The thymus gland is the site of maturation for T cells, which migrate from the red bone marrow
• T cells learn to recognize combinations of self and foreign molecules
• Mature T cells in the bloodstream encounter foreign molecules or cells
• These T cells will then proliferate and become activated

Lymph nodes

• Axillary lymph nodes are in the underarm region
• Inguinal lymph nodes are located in the groin region

Lymph Nodes

• A capsule surrounds the cortex and medulla
• Macrophages concentrated in medulla cleanse lymph
• Macrophages "present" debris or pathogens to T cells
• B and T cells destroy pathogens, and lymph nodes are named for their location

The Spleen

• The spleen is in the upper left side of the abdominal cavity, just posterior to the stomach
• Macrophages remove old and defective blood cells
• Red pulp filters and cleanses blood

Tonsils

• These are patches of lymphatic tissue in the pharynx
• They prevent entry of pathogens through the nose and mouth

Peyer Patches

• Peyer Patches are located in the intestinal wall

Vermiform Appendix

• This is attached to the cecum

The Lymphatic organs

• Blood cells, including lymphocytes, are produced in red bone marrow
• B cells mature in the bone marrow
• T cells mature in the thymus
• Lymph is cleansed in lymph nodes
• Blood is cleansed in the spleen

White pulp

• White blood cells are produced and mature here

Immunity

• The ability to remove or kill foreign substances, pathogens, and cancer cells

Innate Defenses

• These do not distinguish one type of threat from another
• They're fully functional without previous exposure to invaders
• It occurs immediately or shortly after infection

Innate Immune Defenses

• Innate immune defenses can be physical and chemical barriers to entry
• The inflammatory response is also part of this
• Phagocytes and natural killer cells part of it
• Protective proteins such as complement and interferons are part of it

Physical and Chemical Barriers

• Skin and mucous membranes line the respiratory, digestive, and urinary tracts
• Cilia lining the respiratory tract sweep mucus and particles into the throat
• Antimicrobial molecules in secretions of oil glands, mucous membranes, and the stomach assist the response
• Mucus contains lysozyme, an enzyme that lyses bacteria and the acidic pH of stomach kills microbes

Inflammatory Response

• This is a localized tissue response to injury
• Damaged cells and mast cells release histamine, causing capillaries to dilate and become more permeable
• Enlarged capillaries cause skin to redden, and swelling stimulates free nerve endings, causing pain
• Neutrophils and monocytes migrate to the site of injury
• Monocytes differentiate into macrophages
• Macrophages release colony-stimulating factors to stimulate white blood cell production and release
• Neutrophils, dendritic cells (antigen-presenting cells), and macrophages phagocytize pathogens
• Acute phase proteins, released by the liver, make it easier for phagocytes to engulf invaders

Fever

• Fever indicates a maintenance of an elevated body temperature
• A fever informs the body that something is wrong, and certain bacteria or viruses may not survive as well
• Some immune mechanisms work better at higher body temperatures

Phagocytes

• They leave the bloodstream and phagocytize bacteria
• They release antimicrobial peptides and bacteria-digesting enzymes
• They generate free radicals which kill engulfed bacteria

Eosinophils

• Type of phagocytic cells
• They mount an attack against parasites that are too large to be consumed via phagocytosis

Macrophages and Dendritic Cells

• They engulf and destroy pathogens
• They stimulate T cells in lymph nodes, which initiate adaptive immune response

Natural Killer Cells

• Large, granular lymphocytes
• They kill virus-infected cells and cancer cells by cell-to-cell contact
• Cells lacking a self molecule (MHC-1) may be recognized and killed
• Numbers do not increase after stimulation, unlike lymphocytes

Protective Proteins: Complement

• A collection of plasma proteins "complement" immune responses
• Must be activated by pathogens
• Helps to destroy pathogens in three ways
  • Enhanced inflammation
  • Bind to pathogens coated with antibodies to ensure phagocytosis
  • Form a membrane attack complex that produces holes in bacteria and viruses
    • Fluids entering bacterial cell or virus cause bursting

Interferons

• They are cytokines that affect the behavior of other cells
• They are produced by virus-infected cells
• They bind to the receptors of non-infected cells, which causes them to produce substances that interfere with viral replication
• It can also treat certain cancers and viral infections like hepatitis C

Adaptive Immune Defenses

• Adaptive immunity is acquired and not inborn
• It takes 5-7 days to activate
• Recognition of an antigen
• Response to the antigen
• Memory of the antigen are involved in the three steps
• An antigen is any substance that stimulates the immune system to react

Lymphocytes

• Lymphocytes can recognize and bind to specific antigens
• They have antigen receptors on their plasma membrane, and the receptor protein's shape allows it to combine with a specific antigen.
• Pathogens, cancer cells, and transplanted tissues/organs bear antigens that the immune system recognizes as nonself.

Adaptive immunity is primarily the result of B cells

• B-cell receptors bind directly to antigens
• B cells give rise to plasma cells that produce and secrete antibodies

T cells

• T-cell receptors bind to antigens presented by antigen-presenting cells
• Helper T cells regulate specific immunity, and Cytotoxic T cells kill virus-infected cells and cancer cells

Clonal Selection Theory

• The antigen selects which lymphocyte will undergo clonal expansion and produce more lymphocytes
• Most cloned lymphocytes become plasma cells that produce specific antibodies
• Some of the cloned lymphocytes become memory B cells
• If the same antigen enters the system again, memory B cells quickly divide, giving rise to more lymphocytes that are capable of producing antibodies quickly

Antibodies

• Immunoglobulins consist of two heavy and two light polypeptide chains in a Y shape
• Both types of chains have variable and constant regions
• Pathogens are neutralized by coating their antigens, preventing them from binding to receptors on cells
• They attract white blood cells that move in for the kill
• Immune complexes may be engulfed by neutrophils/macrophages
• Immune complexes may active the complement system
• Class is determined by the structure of the antibody's constant region such as IgG, IgA, IgM, IgE

Immunoglobulin G (IgG)

• IgG is the main type of antibody in circulation

Immunoglobulin (IgA)

• IgA is the main type secreted in milk, tears, and saliva

Immunoglobulin M (IgM)

• IgM is first antibody produced and indicates infection

Immunoglobulin E (IgE)

• IgE is bound to receptors on eosinophils and mast cells in tissues

###T cells

• T-cell receptors (TCR) recognize antigens displayed by antigen-presenting cells (APCs)
• Antigen is first linked to a major histocompatibility complex (MHC) protein in the plasma membrane of the APC.
• After the T-cell receptor binds to the antigen, the T cell undergoes clonal expansion
• After the immune response has been successful, most of the T cells undergo apoptosis
• Some T cells remain as memory T cells

Cytotoxic T Cells

• Destroy antigen-bearing cells
• They contain storage vacuoles containing perforins and granzymes

Helper T Cells

• They activate other T cells and B cells
• They regulate immunity by secreting cytokines (signaling molecules

Memory T Cells

• They persist after a successful immune response and provide protection if the same antigen is encountered again

HIV

• The primary host for HIV is a helper T cell
• The host (helper T cell) produces viruses that go on to destroy more helper T cells
• At first, the individual stays ahead of the virus by producing enough Helper T cells
• Eventually, the HIV count rises and the Helper T-cell count drops which affects patients and they become susceptible to opportunistic infections
• Opportunistic infections are thus, a characteristic sign of an AIDS diagnosis.

Cytokine

• Can act as soluble protein and has the function act as a signaling molecules
• Cytokines aka interleukins are manufactured via white blood cells
• Stimulate other white blood cells
• Interleukins stimulate theimmune system and might trigger destruction of certain cancer.
• IL-2 treat specified kidney disease and melanomas.

TNF

Soluble protein made by macrophages

• Encourages the immune system via inflammatory reactions.

• Causes the cell deaths in cancer ptoduction

• Anti-TNF: Possible medication in development to combat immune type illness.

Active Immunity

• It happens because of a individuals immune system acting on a antigen given in body

Immunization

• Uses vaccination with contains a antigens being countered in a system =Pathogens/ by products being treated are then given via vaccine
• relies to have some memory B with memory T cells that encourage ability counter lower measurements antigen presence.

Passive Immunity.

• Individuals can recieves antibody,immunoglobuilens, or other related immune systrm factors in other species.
• is short lived since new born babies has a immune state from mothers blood passed of the placenta and breast milk encourages more help in the new born.

Use potentiality of disease cases.

• In a human who has exposed to disease factors, is used for such effects
• Rabeies, Tetanium, batulism, and snake bites are samples

Also, it can be passed from marrow production from donors blood if the patient's immunity needs more marrow due to the lack of cellular function.

immune deficiency.

• More sucepectubilty to disease.

Primary.

• Genetics are passed on to offspring such as.

SCID/Severe Combined Issues

• Both B cells and T's cells do not work and are non functioning type cells.

• in several months the child gets no benfits from antibody and most are degrade causing untreated infnats expire death.

• Tranplants can assist.

• X- Linked Agamm Blood probs.

  • It causes the X chromsome cells to not be properly produce the correct amount of proper B cells for the body.

• Allergy

  • Immune factor acts that has potentiality issues. .
  • Allergic reaction. Allergy has a factor from histamine release that can affect sympotoms seen during that type of bodily function.

• individuals can struggle to breath if they suffer to the affects seen.

  • Anabolic shock cases can be fatal if the agent got into someones blood lines life threatening effects due to immune issues

• Memory T can act by cytokines.

• Clonal allergy factors.

1 B's cell has to attach to to lGE in antibodies that has a release rate effect from for cellular events.

• Arthirirts

Caused by many issues that encourages the effect in the joints. it makes immunity drop and be under system. .

• Systemic/ immune disorder.
• Can be passed if given to person and their is rash on their bodies from the immune factors.
• Transplant, can cause rejection effects and can have antibodies to toxity if rejection happnes. .
• Genetic enginnering could possible assist in MHC but is an issue.
• T issue can be an rejection prob.