Immunology

Question 1

Innate immunity

Answer 1

Built-in ability to detect and attack pathogens.
Is activated immediately upon detection of damage or infection.
Response time: minutes/hours.
Cells: phagocytes, natural killer cells, other leukocytes.
Non-specific.

Question 2

Adaptive immunity

Answer 2

Acquired ability to recognize and destroy pathogens.
Respond after being presented with antigens obtained via the innate system.
Response time: days.
More diverse than innate immunity.
More specific than innate immunity, can discriminate between even minor differences in molecular structure of molecules.
Cells: T-cells, B cells, antigen-presenting cells.

Question 3

Phagocytosis

Answer 3

When a phagocyte (white blood cell) engulfs a pathogen.
Involves macrophages, neutrophils, monocytes, dendritic cells, and osteoclasts.
1) recognition and adherence: when a PAMP (pathogen-associated molecular pattern) binds with a toll-like receptor.
PRRs (pattern recognition receptors) recognize the PAMP.
2) engulfment: extensions of the cytoplasm move around and enclose the particle (phagosome).
3) intracellular killing: the phagosome fuses with the lysosome, which contains antibacterial molecules and enzymes that can kill and digest the microbe. imagine two bubbles/vacuoles merging

Question 4

Microbial invasion response

Answer 4

1st line of defense: skin, hair, mucus, digestive enzymes in mouth, stomach acid.
2nd line of defense: cellular responses to infection. (macrophages, dendritic cells, binding, cell activation…
3rd line of defense: activation of the adaptive immune responses.

Question 5

Inflammation

Answer 5

Mass cells recognize the increase of pathogens and release of histamine.
The increase of blood flow causes infected areas to swell and heat up.
Cytokines released increase the immune response.

Question 6

Immune cells

Answer 6

A cell that is part of the immune system and helps the body fight infections and other diseases.
Develop from stem cells in the bone marrow and then become different types of white blood cells.

Question 7

Lymphoid organs

Answer 7

Primary: thymus and bone marrow.
Secondary: lymph nodes, spleen, others.
T cells are formed in the bone marrow and more to the thymus for maturation.
B cells are formed and go to the secondary organs for maturation.

Question 8

Antibody production

Answer 8

B cells have antibodies on them, antigens connect, B cell clones and some are separated as memory cells.
Memory cells keep a memory of the antigen they were exposed to.
Memory B cells activate plasma B cells which will make antibodies.
Memory T cells activate cytotoxic T cells which will go after infected cells.

Question 9

T cells

Answer 9

Part of the immune system that focuses on specific foreign particles.
Circulate until they encounter their specific antigen.
Helper T cells and cytotoxic T cells.

Question 10

Toll-like receptors

Answer 10

Recognize many types of pathogen molecules to provoke innate immune responses.

Question 11

Immunological memory

Answer 11

Produces mature T cells.
Upon reinfection, many T cells and B cells will be available because of memory.
Second response for the adaptive immune system is much faster and more effective.

Question 12

Components of the innate immune system

Answer 12

Physical barriers

Internal defenses: inflammatory response, complement proteins, phagocytic cells, natural killer cells.

Question 13

Components of the adaptive immune system

Answer 13

Antibodies and the humoral immune response.
Cell-mediated immune response.
Memory response.

Question 14

Complement system (innate)

Answer 14

Sequentially interacting proteins resulting in the destruction of microorganisms.
Complements the actions of the immune system.

Question 15

Leukocytes

Answer 15

White blood cells.

Can be macrophages, neutrophils, eosinophils, basophils, B cells, or T cells.

Question 16

Pathogen

Answer 16

A bacterium, virus, or other microorganism that can cause disease.

Question 17

Macrophage

Answer 17

Part of the 2nd line of defense.
White blood cell.
Consumes pathogens.
Innate immune system.

Question 18

Cytotoxic T cell

Answer 18

Part of the 3rd line of defense.
Destroys infected cells.
Part of the cell-mediated response.
Releases signals that cause the infected cell to do apoptosis (self-destruct).
Adaptive immune system.

Question 19

Helper T cells

Answer 19

Part of the 3rd line of defense, help activate other white blood cells with specific antigens, part of the cell-mediated AND humoral responses.

Question 20

Antigens

Answer 20

Something the immune system recognizes as foreign to the body.

Question 21

Antibiotics

Answer 21

Substances that can specifically destroy bacteria.

Question 22

Antibodies

Answer 22

Proteins that tend to be in a Y shape.
Bind to a specific antigen.
Characterized by heavy stem (base) and light chains (arms).
imagine Y shaped antibody binding to a triangle shaped antigen