Immunity

Antigens

(Anti-body Generator) - Any foreign substance that your body causes your immune system to ID to a pathogen and create an antibody against it

WBCs

(Leukocytes) - Have full VIP access to most of the body (not CNS) - can squeeze in-between blood vessels (diapedesis) - phagocytes

Innate immunity

(Nonspecific). - Responds to all kinds of pathogens quickly the same whether or not your body has seen them before - job is to keep the pathogen from getting in

Phagocytes

(eating-cells) - Any cells that ingests cells by the process of phagocytosis - chase down invading cells and engulf them

Allergens

Things that aren't necessarily harmful that our immune system triggers an inflammatory response to.

Antihistamines

To suppress the histamine trigger so that your immune system won't trigger an inflammatory response

Dendritic cells

Type of phagocyte that hangs out on the surface of the body and comes in - eat up pathogens -carry info back to the spleen or lymph nodes and remembers it (acquired immune system)

Pathogens

Viruses and organisms that want to turn other cells into a factory to manufacture more of themselves.

Describe what happens when a B-cell comes in contact with an antigen.

When a B-cell comes in contact with an antigen (assuming the B-cell has the right antibody for binding) specific B-cells are selected by "clonal selection". The B-cell begins to clone itself into effector plasma cells and memory cells. The plasma cells manufacture antibodies that can break off and bind to the antigen. Memory cells stick around and serve as an immunity function for future responses.

What does a dying cell do in the final moments of its life? Explain in detail.

When a cell becomes infected it starts presenting antigens from the infecting pathogen and helper T cells signal over cytotoxic T cells to digest and engulf the infected cell.

Describe the inflammation response.

When a mast cell comes across a pathogen or an allergen, it releases histamines to allow the blood vessels to dilate. This allows WBCs to come in and act on the substance.

Inflammation response

When histamines cause vessels to dilate and fluid rushes to the the source where histamines are released and causes swelling.

How and why do we have an allergic response?

When your immune system triggers an inflammatory response to something non harmful such as pollen or dust. Your body does this because it thinks that the substance is harmful but may not be. It is done when mast cells release histamines when it comes in contact with the allergen an induces an allergic response.

Lymphocyte

cells in the immune system that attack things they already know about. There are two main kinds: (1) T-cells and (2) B-cells. - There are two kinds of lymphocytes because we have two types of acquired immunity which are (1) Cell mediated response and (2) Humoral response

What animals have innate immunity & what have acquired immunity?

every animal has innate and only acquired is found in vertebrates

Describe your 1° line of defense.

skin and mucus membranes. - The skin keeps things out/things in and is oily and acidic. - Mucus forms a barrier and is secreted by mucus membranes that trap organisms. - Epithelial tissue has dendritic cells that present antigen info to immune system

Describe the differences in the cells that engage in phagocytosis.

- Neutrophils: engulf one microbe and then roll over and die and accumulate into pus. - WBCs or Leukocytes: can squeeze by blood vessels into an area where histamine is released by mast cells - Macrophages: Don't really travel and can eat a lot and engulf cells that have gone rogue. - Natural Killer Cells: Detect when cells in the body stop secreting MHC (cancerous or infected) and can kill these cells. - Dendritic Cells: Engulf pathogens and carry information about them back to the spleen and vary between the acquired and innate immune system.

Acquired Immunity

- develops more slowly and involves the body learning the pathogen before it responds to it. -stores information based on pathogens that it comes in contact to in order to create defenses.

MHC-1

A protein that is secreted by all normal healthy cells. - When a cell becomes infected or cancerous, it stops secreting this protein - The Natural Killer cells recognizes this and binds to it and breaks it down (kill it).

Macrophages

A type of phagocytic cells that are the "big eaters". - Hang out like body guards in the organs that kill outside invaders - can also detect when one of our cells has gone rogue (cancer cells) and kill those too - don't die after killing a bacterium but usually up to 100 microbes before they do die.

Antigen presentation (by HLA = MHC molecules)

After a macrophage destroys a pathogen, it has the ability to shred the proteins from the pathogen and present the antigen on its membrane surface. - Helper T-cells can attach to this and releases interleukin 2 to signal it to make more T-cells (effector for signaling and memory cells for keeping record) and memory T-cells.

How did antigens get their name?

Antibody Generator

Helper T-cells

Attracted to and help attack microbes in other macrophages. - Phagocytes engulfing a microbe will present MHC-2 molecules with the antigen of the present microbe on it outside the cell. -These cells are attracted to the MHC-2 bound antigen and help phagocytose the microbe

Cytotoxic T-cell

Binds to infected cells that make MHC molecule with the antigen on it outside the cell. This cell recognizes that MHC bound antigen and process to destroy the infected cell.

Memory T-cells

Both Helper T-cells and Cytotoxic T-cells form memory cells of each themselves.

Mast cells

Constantly search for suspicious objects like unknown proteins. They also release signal molecules like histamine.

Describe the function of B-cells.

Functional in the humoral response. They are covered in antibodies that detect and bind to antigens. When a B-cell with the appropriate antibody binds to a known antigen, the B-cells begin cloning into plasma (effector) B cells (creates antibodies specific to bound antigen to signal phagocytes) and memory B cells (provide future immunity)

Antibodies

Highly specialized proteins that are produced by B-cells to recognize and trigger an immune response to. - Can swarm over the invading substance and make it harder for it to move - Serve as tags that release chemical signals to nearby phagocytes to kill the invader.

Describe your 2° line of defense.

Inflammatory response - Ruptured mast cells release histamines which dilate blood vessels - attracts WBCs, macrophages and mast cells. - macrophage wanders over and extends pseudopods around the pathogen and breaks it down.

Cell-mediated response

Is the immune response for when the cells are already infected. - Process mainly involves T-cells and there are many of these responses.

Humoral response

Is the immune response is in the body's fluids not the cells.

What can (and can't) leucocytes do?

Leukocytes can squeeze in between blood vessels but can't enter the CNS

Histamines

Makes your blood vessels more permeable which allows fluids to flow to the site and causes inflammation. Brings in WBCs.

Neutrophil

Phagocytic cells. Abundant in the bloodstream and can move freely in it. They can quickly get to the invading microbe and kill it. These cells die after killing a microbe and collect into pus.

Why is it important that macrophages "present" antigens from pathogens they killed?

So that if the same antigen comes in contact, then B-cells can undergo clonal selection and produce more antibodies to act upon that antigen.

B-cells

|| Acquired Immunity||Can remember old enemies. - Made in the bone marrow and spleen - attack bacteria and extracellular pathogens - Have antibodies attached to their surface (can break off too)/ can make them. - B-cells with needed antibody undergoes "clonal selection" and clones into (a) Plasma cells (effector B cells) and (b) Memory cells.

T-cells

||Acquired Immunity|| - Form in the bone marrow and mature in the thymus - Specialize in attacking viruses - There are 2 types of T-cells. (a) Cytotoxic T-cells and (b) Helper T-cells. - Infected cells make MHC molecules that bind to virus proteins inside the cell. The MHC molecule binds to the protein and then moves the molecule to the outside of the cell where the antigen is exposed. Cytotoxic T-cell destroys the infected cell.

Natural killer cells

The only phagocytic cell in the innate immune system that destroys other human cells. -When cells are healthy they have MHC-1 on their surfaces. - When a cell is infected or cancerous, it doesn't secrete MHC-1 and these phagocytes bind to it and secrete an enzyme that dissolves its membrane.

Memory B cells

These B-cell clones are specialized after clonal selection to produce Plasma Cells. These cells keep record of the antigen and

Plasma B cells

These B-cell clones are specialized after clonal selection to produce antibodies that tag the pathogens.

Describe how antibodies act.

They act by binding to antigens on a pathogen and aid in slowing it down and making it harder to move. They serve as tags that signal to nearby phagocytes to come and destroy the invading pathogen.