Zoology Immunology Semester V Quiz

Structure and Function of T and B Cells

• T cells and B cells are crucial components of the adaptive immune system.
• T cells are responsible for cell-mediated immunity, while B cells are responsible for humoral immunity.
• T cells develop in the thymus and include subtypes such as helper T cells and cytotoxic T cells.
• B cells mature in bone marrow and produce antibodies to neutralize pathogens.

Differentiate T Helper and T Cytotoxic Cells

• T helper cells (CD4+) assist other immune cells by releasing cytokines.
• T cytotoxic cells (CD8+) directly kill infected or cancerous cells.
• T helper cells activate B cells and enhance the activity of macrophages.

Structure and Function of Granulocytes

• Granulocytes are a type of white blood cell with granules in their cytoplasm.
• Three main types: neutrophils (phagocytize pathogens), eosinophils (combat parasites), and basophils (release histamine).
• Essential for the inflammatory response and defense against infections.

Structure and Function of Thymus

• The thymus is a lymphoid organ located in the upper chest.
• It provides a site for T cell maturation and differentiation.
• Produces thymosin, which stimulates T cell development.

Bone Marrow

• Bone marrow is the primary site of hematopoiesis (formation of blood cells).
• Contains stem cells that differentiate into red blood cells, white blood cells, and platelets.
• B cells mature here before entering the bloodstream.

Lymph Node

• Lymph nodes are small, bean-shaped structures that filter lymph fluid.
• Act as hubs for immune cell activation, proliferation, and response to pathogens.
• Contain B cells, T cells, and macrophages for monitoring and fighting infection.

Spleen

• The spleen filters blood and helps mount immune responses.
• Contains red pulp (removes old or damaged red blood cells) and white pulp (rich in lymphocytes).
• Acts as a site for antigen presentation and T and B cell activation.

MALT (Mucosa-Associated Lymphoid Tissue)

• MALT includes lymphoid tissues associated with mucosal surfaces (e.g., gut, respiratory tract).
• Responsible for generating immune responses to pathogens encountered through mucosal surfaces.
• Components include Peyer’s patches in the intestine and tonsils.

Inherent or Innate Immunity

• Innate immunity is the body's first line of defense against pathogens.
• Includes physical barriers (skin, mucous membranes) and immune cells (phagocytes, natural killer cells).
• Provides immediate but non-specific responses to infection.

Acquired Immunity

• Acquired immunity develops after exposure to a specific pathogen.
• Characterized by the formation of memory cells and a stronger response upon re-exposure.
• Can be acquired naturally (infection) or artificially (vaccination).

Physical and Chemical Barriers

• Physical barriers include skin and mucosal membranes that prevent pathogen entry.
• Chemical barriers include secretions such as saliva, gastric acid, and antimicrobial peptides.
• Both types work together to limit pathogen access to the body.

Inflammation

• Inflammation is a protective response to tissue injury or infection.
• Involves the release of signaling molecules that recruit immune cells to the site of damage.
• Symptoms include redness, heat, swelling, and pain.

Phagocytosis

• Phagocytosis is a process by which certain immune cells engulf and digest pathogens.
• Key phagocytic cells include macrophages and neutrophils.
• Plays a critical role in clearing infections and debris from tissues.

Types of Immunity

• Two major types: innate immunity (non-specific, immediate) and adaptive immunity (specific, delayed).
• Adaptive immunity further divides into humoral immunity (B cells producing antibodies) and cell-mediated immunity (T cells).

Humoral Immunity

• Mediated by B cells and involves the production of antibodies specific to antigens.
• Key in defending against extracellular pathogens and toxins.
• Antibodies neutralize toxins and enhance the opsonization and clearance of pathogens.

Cell Mediated Immunity

• Involves T cells, particularly cytotoxic T cells that destroy infected host cells.
• Critical for eliminating intracellular pathogens and cancer cells.
• Also involves helper T cells, which coordinate the immune response.

Compare the Two Classes of MHC

• Major Histocompatibility Complex (MHC) Class I presents antigens to CD8+ T cells and is found on all nucleated cells.
• MHC Class II presents antigens to CD4+ T cells and is expressed on professional antigen-presenting cells (e.g., macrophages, dendritic cells).

Explain the HLA Locus

• The Human Leukocyte Antigen (HLA) locus is a complex of genes on chromosome 6.
• Includes genes for MHC molecules critical for immune system function.
• Plays a significant role in the body’s ability to recognize self versus non-self.

Significance of MHC in Organ Transplantation

• MHC compatibility is crucial for successful organ transplantation to minimize rejection.
• Donor and recipient MHC must be matched to reduce the risk of immune response against the transplanted organ.
• HLA typing prior to transplantation helps find suitable matches.

Test your knowledge on immunology topics covered in Semester V at Sardar Patel College. This quiz includes questions on T and B cells, different types of immune cells, and key components of the immune system such as the thymus, spleen, and lymph nodes. Challenge yourself to differentiate between innate and acquired immunity.