Immunology First and Second Lines of Defense

Lysozyme is an antimicrobial enzyme that destroys the cell wall of bacteria. It is found in tears, saliva, mucus secretions, and perspiration.

Monocytes

<p>Phagocytosis</p> Signup and view all the answers

<p>Fever (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Complementary proteins, also known as complement proteins, help to kill pathogens by forming a protective barrier, puncturing the cell membrane, and attracting phagocytes to the site of infection.</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>B-cells (C)</p> Signup and view all the answers

<p>Red blood cells (D)</p> Signup and view all the answers

<p>Helper T-cells identify foreign antigens and release chemical messengers called lymphokines. These lymphokines activate B-cells to clone and produce antibodies and activate killer T-cells.</p> Signup and view all the answers

<p>Killer T-cells destroy infected cells by puncturing their cell membranes. In the case of viruses, they can also destroy infected cells, preventing the spread of the virus.</p> Signup and view all the answers

<p>Suppressor T-cells signal the immune system to shut down after the invader is eliminated. This helps to prevent the immune system from attacking healthy cells.</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>HIV/AIDS targets and destroys helper T-cells, which are essential for coordinating the immune response. This weakening of the immune system makes individuals more susceptible to infections, including bacterial, fungal, and viral infections.</p> Signup and view all the answers

<p>Interfere with viral replication (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Engulfment and destruction of pathogens</p> Signup and view all the answers

<p>lymphocyte</p> Signup and view all the answers

<p>B cells = Produce antibodies Helper T cells = Activate B cells and cytotoxic T cells Cytotoxic T cells = Directly kill infected cells Antigen-presenting cells (APCs) = Initiate adaptive immunity by presenting antigens</p> Signup and view all the answers

<p>Causes an enhanced response to previously encountered pathogens (D)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Humoral immunity and cell-mediated immunity</p> Signup and view all the answers

Physical barriers such as skin, cilia, earwax, and mucous membranes protect against viral and bacterial invaders. Lysozyme, an antimicrobial enzyme found in tears, saliva, mucus, and sweat, destroys bacterial cell walls.

Foreign particles that enter through a skin injury are attacked by leukocytes called monocytes, which transform into macrophages in the tissues.

Neutrophils, a type of white blood cell, are attracted to chemical signals released by damaged tissues and microbes. This process, called chemotaxis, guides neutrophils to the infection site.

A type of white blood cell that engulfs and destroys invading microbes.

A mixture of dead white blood cells, digested invaders, and proteins. It's a sign of the body fighting an infection.

A localized response to tissue damage characterized by swelling, redness, heat, and pain. It's a sign that the second line of defense is working.

A series of reactions that occur after an invader bypasses the first line of defense.

Fever increases the body's temperature, making it difficult for bacteria to survive. It's a natural defense mechanism.

Antimicrobial proteins in the blood that are activated when they encounter foreign substances. They can trigger protective barriers, puncture cell membranes, or attract phagocytes to destroy invading pathogens.

They are antimicrobial plasma proteins that are activated by the presence of foreign organisms. These proteins can be found in the blood in inactive form and are activated when they encounter foreign materials.

After eliminating bacteria, some macrophages travel throughout the body, while others remain in tissues, filtering microorganisms and foreign invaders from the blood.

A type of white blood cell that produces antibodies to fight off infections. They are mature in the thymus, lymph nodes, and spleen.

The two main types of lymphocytes are T-cells and B-cells. T-cells mature in the thymus and identify invaders, while B-cells mature in the bone marrow and produce antibodies.

A bacterium enters the body, a macrophage engulfs it, presenting its antigen on its membrane. A helper T-cell recognizes the foreign antigen and releases lymphokine.

Lymphokine activates B-cells to divide, creating identical clones. Helper T-cells send a second message to B-cells for antibody production. Killer T-cells are also activated.

Killer T-cells destroy the invading cells by puncturing their membranes. In case of viral infections, infected cells are destroyed to prevent viral reproduction. Suppressor T-cells signal the immune system to shut down.

Memory B-cells retain information about the antigen, allowing for a faster response if the same invader attacks again.

HIV attacks T-cells, weakening the immune system. This makes the body vulnerable to opportunistic infections like tuberculosis, pneumonia, meningitis, and herpes.

A physical barrier that prevents invaders from entering the body. Example: Skin.

The process by which white blood cells engulf and destroy pathogens. Example: Neutrophils engulfing bacteria.

Chemical signals released by damaged cells that attract white blood cells to the site of infection. Example: Damaged tissue releasing chemicals to attract neutrophils.

Specialized white blood cells that produce antibodies. Example: B-cells.

A protein molecule produced by B-cells that binds to specific antigens. Example: Antibodies attacking bacteria.

A substance that triggers an immune response. Example: Bacterial proteins.

A type of white blood cell that identifies and destroys infected cells. Example: Killer T-cells attacking virally infected cells.

A type of white blood cell that helps activate other immune cells. Example: Helper T-cells signaling B-cells to produce antibodies.

A type of white blood cell that suppresses the immune response after the threat is neutralized. Example: Suppressor T-cells stopping the production of antibodies.

A type of immune response where B-cells produce antibodies to fight off infection. Example: The body's response to a viral infection.

A type of immune response that involves T-cells destroying infected or cancerous cells. Example: The body's response to a viral infection.

The ability of the immune system to recognize and respond to specific antigens. Example: The body remembering a specific virus and quickly responding on a second encounter.

An enzyme found in tears, saliva, and mucus that breaks down bacterial cell walls.

White blood cells that engulf and destroy foreign particles, like bacteria.

The process by which macrophages engulf and destroy foreign particles.

Chemicals released by damaged tissues that attract neutrophils to the site of infection.

The body's localized response to injury or infection, characterized by swelling, redness, heat, and pain.

A temporary increase in body temperature, activated by macrophages, that inhibits bacterial growth.

Proteins that enhance the immune response by forming barriers, puncturing cell membranes, or attracting phagocytic cells.

A type of white blood cell that matures in the thymus and identifies specific pathogens.

A type of white blood cell that matures in the bone marrow and produces antibodies.

Proteins produced by B-cells that bind to specific antigens, helping to neutralize pathogens.

Substances that trigger an immune response and bind to antibodies.

Chemicals released by helper T-cells that stimulate B-cell division and antibody production.

T-cells that destroy infected cells and invaders directly.

A complex system of proteins that enhances inflammation, phagocytosis, and pathogen lysis by forming barriers, puncturing cell membranes, or attracting phagocytic cells.

The process by which lymphocytes recognize and target specific pathogens or antigens, leading to a tailored immune response.

Specialized cells that present fragments of antigens to T cells, initiating adaptive immunity.

A series of reactions that occur in response to an infection or injury, involving the recruitment and activation of immune cells, leading to redness, swelling, heat, and pain.

A branch of the immune system that relies on specialized lymphocytes, such as T cells and B cells, to recognize and target specific pathogens or antigens, leading to a tailored immune response.

The ability of the immune system to recognize and respond to specific pathogens or antigens more effectively upon subsequent exposures, due to the presence of memory cells.