immune system

• What are the two main categories of the human body's defense system against pathogens?

  Physical and chemical barriers, immune system
• The skin acts as a physical barrier that pathogens cannot penetrate
• What substances secreted by the skin help kill pathogens?

  Oils and antimicrobial substances
• Pathogens can enter the body through the skin

  False
• The nose contains hairs and mucus to trap pathogens entering through air
• What are the only two tubes leading from the throat?

  Trachea and esophagus
• Steps of pathogen trapping in the respiratory system

  1️⃣ Pathogens enter the trachea

  2️⃣ Mucus traps the pathogens

  3️⃣ Cilia move mucus up the throat

  4️⃣ Mucus is swallowed into the stomach
• What strong acid in the stomach kills pathogens?

  Hydrochloric acid
• The pH of the stomach contents is reduced to about 2
• Some pathogens can survive the stomach's acidic environment
• What is the main component of the immune system that fights pathogens?

  White blood cells
• White blood cells patrol the body circulating in the blood and tissues
• Match the white blood cell function with its description:

  Phagocytosis ↔️ Engulfs and destroys pathogens

  Antitoxin production ↔️ Neutralizes toxins produced by pathogens

  Antibody production ↔️ Creates proteins to target antigens
• What are toxins produced by pathogens that damage cells?

  Poisons
• Antitoxins bind to toxins, neutralizing their harmful effects
• Antibodies are specific to particular antigens
• What is an antigen detected by the immune system?

  Foreign substance
• Antibodies signal white blood cells to destroy antigens
• What happens when the immune system encounters a pathogen it remembers?

  Produces antibodies rapidly
• Immunity to a disease means the body can destroy pathogens before they cause symptoms
• The human immune system protects against pathogens every day
• What does the term "monoclonal antibodies" refer to?

  Antibodies from a single clone
• Antibodies are small proteins produced by B lymphocytes, also known as B cells
• What is the role of antibodies in the immune system?

  Bind to antigens
• Antigens are foreign molecules that antibodies bind to
• When B cells detect antigens, they produce loads of antibodies
• Why do B lymphocytes need to be combined with tumor cells to produce monoclonal antibodies on a large scale?

  To divide rapidly
• The fusion of B cells and tumor cells results in a cell called a hybridoma
• Steps to produce monoclonal antibodies using hybridoma cells

  1️⃣ Combine B lymphocytes with tumor cells

  2️⃣ Form hybridoma cells

  3️⃣ Allow hybridoma cells to divide

  4️⃣ Collect and purify antibodies
• How is the immune system of an animal stimulated to produce specific B lymphocytes for monoclonal antibodies?

  Inject with antigen
• Monoclonal antibodies bind to only one specific antigen
• Monoclonal antibodies can be attached to drugs, fluorescent proteins, or radioactive material
• How can monoclonal antibodies be used to treat cancer cells?

  Deliver drugs or radiation