Contrast the terms in the following pairs:
a. innate and adaptive immunity
b. humoral and cellular immunity
c. active and passive immunity
d. TH1 and TH2 cells
e. natural and artificial immunity
f. T-dependent and T-independent antigens
g. immunoglobulin and TCR

Verified step by step guidance

1. Step 1: Define 'innate immunity' as the non-specific first line of defense against pathogens, present from birth, and 'adaptive immunity' as the specific immune response that develops after exposure to antigens.
2. Step 2: Explain 'humoral immunity' as the aspect of immunity mediated by macromolecules found in extracellular fluids, such as antibodies, and 'cellular immunity' as the immune response that involves the activation of certain immune cells to fight off pathogens.
3. Step 3: Describe 'active immunity' as the immunity that results from the production of antibodies by the immune system in response to the presence of an antigen, and 'passive immunity' as the short-term immunity that results from the introduction of antibodies from another person or animal.
4. Step 4: Differentiate 'TH1 cells' as a subset of T helper cells that are involved in the activation of macrophages and are important in cell-mediated immunity, and 'TH2 cells' as another subset of T helper cells that assist in stimulating B cells to produce antibodies.
5. Step 5: Contrast 'natural immunity' as the immunity acquired through natural exposure to pathogens, and 'artificial immunity' as the immunity gained through medical interventions such as vaccines.

Key Concepts

Innate and Adaptive Immunity

Innate immunity is the body's first line of defense, providing immediate but non-specific protection against pathogens through physical barriers and immune cells like macrophages. In contrast, adaptive immunity develops over time and is specific to particular pathogens, involving lymphocytes (B and T cells) that remember past infections, allowing for a stronger response upon re-exposure.

Humoral and Cellular Immunity

Humoral immunity involves the production of antibodies by B cells that circulate in body fluids, targeting extracellular pathogens. Cellular immunity, on the other hand, is mediated by T cells that directly attack infected or cancerous cells, playing a crucial role in defending against intracellular pathogens and coordinating the overall immune response.

Active and Passive Immunity

Active immunity occurs when the immune system is exposed to a pathogen and produces its own antibodies, often through infection or vaccination, leading to long-lasting protection. Passive immunity involves the transfer of pre-formed antibodies from one individual to another, providing immediate but temporary protection, as seen in maternal antibodies passed to infants.