Immune System Mechanisms and Functions

What are the four cardinal signs of inflammation, and what causes them?

• Swelling (fluid leakage), Pain (fluid compression/bradykinins), Heat (vasodilation), Redness (vasodilation)

• Fever (hypothalamus activation), Leukocytosis (bone marrow), Joint immobility (severe inflammation), C-reactive peptide production (liver)

• Vasodilation (histamines), Margination (selectins), Diapedesis (amoeboid motion), Chemotaxis (inflammatory chemicals)

• Apoptosis (programmed cell death), Phagocytosis (engulfment), Lysis (MAC formation), Opsonization (C3b tagging)

What is the primary process by which phagocytes eliminate bacteria, and what are some mechanisms involved in this process?

• Complement activation, antibody production, antigen presentation, cytokine release

• Vasodilation, increased permeability, fluid leakage, pain

• Engulfment, phagosome formation, lysosome fusion, oxidative burst or NETs

• Interferon production, protein kinase R activation, natural killer cell activation, apoptosis

Which of the following complement system pathways is directly mediated by antibodies?

• Lectin pathway

• Classical pathway

• Alternative pathway

• Opsonization pathway

How do alpha and beta interferons contribute to the innate immune response against viral infections?

• They directly kill infected cells by inducing apoptosis.

• They activate nearby healthy cells to produce antiviral peptides that prevent viral replication or attachment.

• They enhance the production of antibodies to neutralize the virus.

• They cause vasodilation and increased blood flow to the infected area.

What is the primary function of Toll-like Receptors (TLRs) in the innate immune system?

• To produce antibodies against specific pathogens.

• To directly engulf and digest foreign particles.

• To recognize different types of pathogens and trigger the production of signaling proteins and interferons.

• To regulate blood pressure and fluid balance during inflammation.

Which of the following cytokines are activated by caspases and enhance the inflammatory response?

• TNF, IL-1B, IL-18

• IL-2, IL-4, IL-5

• IL-6, IL-10, IFN-gamma

• TGF-beta, IL-12, IL-17

Which interleukins are primarily responsible for triggering the differentiation of naive T-helper cells into TH2 lymphocytes?

• IL-1 and IL-12

• IL-2 and IL-4

• IL-5 and IL-6

• IL-10 and IFN-gamma

What is the process called when activated B-lymphocytes rapidly multiply after encountering an antigen and receiving appropriate signals?

• Apoptosis

• Differentiation

• Clonal expansion

• Phagocytosis

Which of the following is NOT a primary mechanism by which antibodies eliminate foreign pathogens?

• Neutralization

• Precipitation

• Direct lysis of infected cells

• Opsonization

How do Natural Killer (NK) cells primarily identify and target abnormal cells, such as virally infected or cancerous cells?

• By recognizing specific foreign antigens presented on MHC-II molecules.

• By detecting the absence or abnormality of MHC-I molecules on the cell surface.

• By binding to antibodies attached to the cell surface.

• By directly ingesting the abnormal cells through phagocytosis.