Immune system

half life period

the time it takes for the concentration of a substance in the body to be reduced by half. This concept, known as biological half-life or elimination half-life, is essential for understanding how the body processes and eliminates drugs, hormones, and other substances. 

What are cytokines? Are interferons types of cytokines?

Yes, interferons are a type of cytokine. Cytokines are small, secreted proteins that act as signaling molecules, regulating inflammation and the growth and activity of immune and blood cells

virus infected cells

release interferons which alerts neighboring cells and thus limits spread of virus

What facilitates production of WBC and RBC?

WBC: leukocytes

RBCS: erythropoiesis

colony stimulating factors

substance that stimulates the production of blood cells.

1st line of defense

skin n mucous membranes

mechanical defenses: skin, mucous membranes, tears, saliva, mucus, cilia, epiglottis, urine flow, defecating, vomiting

chemical defenses: sebum by sebaceous gland, lysozyme by lachrymal gland, gastric juice by stomach

2nd line of defense

internal defenses

antimicrobial proteins, phagocytes, natural killer cells (lymphocytes: 5-10%), inflammation, fever

adaptive immunity

the body’s ability to defend itself against specific invading agents.

has both specificity n memory and divided into 2 types:

Cell mediated: cells attacking cells

antibody mediated: act on extracellular pathogens

immunogenicity

provoking immune response

reactivity

ability to react w antibodies

innate immunity

provides quick immediate response to infection

adaptive immunity

delayed but highly specific n long lasting immune response

3rd line of defense

lymphocytes, antibodies, memory cells

non specific defensive (innate immunity)

1st n 2nd line of defense

specific defenses (adaptive immunity)

3rd line of defenses

natural killer cells

attack unwanted cells and cause apoptosis.

What are complements and what do they do?

plasma proteins which binds to antibodies already bound to foreign substance

chemotaxis

movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.

Cardinal signs of inflammation. How a fever inhibits bacterial growth?

The five cardinal signs of inflammation are redness, heat, swelling, pain, and loss of function. A fever inhibits bacterial growth primarily by creating a thermal environment that is unfavorable for the bacteria, while simultaneously boosting the host's immune response. 

What are antigens? How do they bind to antibodies or T lymphocytes?

foreign molecules, often on pathogens, that trigger an immune response by binding to receptors on B cells or T cells. B cells produce antibodies, which bind directly to free antigens, while T cells recognize antigens that are displayed on the surface of other body cells bound to MHC molecules.

What are CD4?

glycoprotein on the surface of immune cells that functions as a co-receptor for the T-cell receptor (TCR) during the activation of T-cells

do you know

Helper T cells have CD4 but pre-T lymphocytes have both CD4
and CD8

How does poison Ivy (hapten) trigger immune response?

binding to skin proteins to form a foreign complex that the immune system attacks. This involves skin cells and Langerhans cells presenting the urushiol-protein complex to T cells in lymph nodes, leading to the activation of T cells. These activated T cells then return to the skin, recognizing the urushiol-protein complexes on cells and triggering type IV hypersensitivity, which causes the characteristic rash, itching, and blistering

cause of mad cow disease

misfolded protein called pion

What do antigen presenting cells do?

presenting antigens (foreign substances) to T cells, which are white blood cells that recognize and fight infections. 

which MHC class (I or II) is specific to APCs

MHC class II is found on professional antigen-presenting cells (APCs), such as dendritic cells, macrophages, and B cells, and is specific to these cells

What are immunoglobulins and effectors of humoral immunity? Structure of antibodies. Which part of antibody does bind to antigens? Which antibody is most prevalent? In which body fluid
IgA is found?

Y-shaped proteins produced by plasma cells that act as the effectors of humoral immunity, neutralizing pathogens by binding to their antigens. The variable regions at the tips of the antibody's "Y" arms bind to antigens, while the constant region interacts with other immune components. IgG is the most prevalent antibody in the blood, and IgA is found in mucosal secretions like saliva, tears, and nasal fluids. 

Role of Cytotoxic T cells, Helper T cells and Memory T cells.

Cytotoxic T cells directly kill infected and cancerous cells, helper T cells coordinate the immune response by signaling other immune cells, and memory T cells provide long-lasting immunity by remembering past infections to mount a faster and more effective response upon re-exposure to the same pathogen

What is opsonization? How this process does lead to marking a target cell for phagocytosis?

the process by which a target—such as a pathogen, dead cell, or tumor cell—is coated with specialized proteins called opsonins. This "tags" the target, making it more easily recognized and ingested by immune cells known as phagocytes. 

What is difference between primary and secondary response? Which one of these two is responsible for rapid production of antibodies?

The secondary immune response is responsible for the rapid production of antibodies, while the primary immune response is slower and less efficient because it's the body's first encounter with a specific pathogen.