SC.912.L.14.52, SC.912.L.18.1, SC.912.L.16.1, SC.912.L.15.8
The Immune System, Macromolecules, Introduction to Genetics, The Origin of
SC.912.L.14.52 The Immune System
Explain the basic function of the human immune systems, including specific and nonspecific immune response, vaccines, and antibiotics. Edgenuity notes:
● Illnesses can be caused by several factors including being exposed to viruses and bacteria. ● There are three components of the immune system: physical barriers, chemical barriers, and biological barriers.
○ Physical barriers
■ Your first line of defense is your skin.
● Your skin helps keep moisture inside.
● It keeps out all the microorganisms that are surrounding us.
● The skin is made of closely packed cells.
● Skin is tough, flexible, and waterproof.
■ Reflexes/ behaviors can also keep pathogens out of your system.
● Watering eyes
○ Chemical barriers
■ Skin secretions
● Antibacterial substance
■ Mouth, eyes, and nose secretions
● Saliva, tears, and mucus
○ Lysozyme a substance found in saliva, tears, and mucus that destroys the cell wall of bacteria
○ Biological barriers
■ Langerhans cells specialized cells in the skin that identify pathogens that enter the body and carry them to the lymph nodes for destruction.
■ Complement system a group of proteins in the blood that detects pathogens that have entered the body.
● Cause inflammation the swelling of the part of the body accompanied by redness, heat, and pain as a response to an infection ● Attract killer T cells
● Attack themselves to pathogens and sometimes kill them
■ White blood cells(leukocytes) the components of blood that help protect against pathogens and help in blood clotting when injuries are sustained.
● Phagocytes(macrophages) a type of white blood cell that engulfs, destroys, and digests pathogens such as bacteria in the body.
● Lymphocytes a type of white blood cell that protects the body from pathogens by producing antibodies
○ B lymphocytes
■ Produced and developed in the bone marrow.
■ Activated by antigens in the body.
■ Produces antibodies.
■ Keeps antigen information for future infections.
○ T lymphocytes
■ Produced in the bone marrow and developed in the thymus. ■ Helper T cells activate B lymphocyte cells to produce antibodies.
■ Helper T cells activate cytotoxic/killer T cells.
● Killer/cytotoxic T cells destroy pathogens and infected cells.
The immune system protects the body against pathogens.
○ Pathogens agents that can cause infection or disease
■ Chemical substances
■ Other foreign materials
There are specific and nonspecific immune responses.
○ Nonspecific immune response include:
■ Complement system
■ Coughing and sneezing
■ Acids, oils, and antibacterial substances
○ Specific immune response:
■ Attacks specific harmful substances.
● Antibodies destroy and immobilize pathogens.
Compromised immune system
○ Allergic disorders immune system overreacts to an antigen
○ Immunodeficiency disorders part of the immune system does not function properly ○
Autoimmune disorders the body’s immune system attacks its healthy cells, mistaking them for pathogens
○ Cancers of the immune system masses of cancer cells form and steal nutrients from healthy cells
Medicine a drug or substance used to treat an injury or an illness
There are different ways a body can respond to medicine:
○ The body is healed from the illness.
■ Medicine kills pathogens.
○ Symptoms of the illness are managed.
■ Pain relievers
● Histamines are chemicals that increase the flow of blood and fluids to the affected area as a part of the inflammatory response.
○ Body builds immunity…