[BIO2F] Lesson 1

Lesson 1: Immunity and Nervous Control

Immune System

• is a complex network of organs, cells, and proteins that defends the body against infection

Innate Immunity

• made up of external and internal defenses

• has the same response to all types of pathogens even if these have been encountered before

Neutrophils

• are a type of white blood cells (leukocytes) that acts as your immune system’s second line of defense

• are suicide warriors that are born to kill and vomit deadly chemicals and die after days of the attack

Macrophages

• first line of defense

• are specialized cells involved in the detection, phagocytosis, and destruction of bacteria and other harmful organisms

• attack and digest 100 bacterias

Natural Killer (NK)

• a type of immune cell that has granules (small particles) with enzymes that can kill tumor cells or cells infected with a virus

Interferons

• a natural substance that helps the body’s immune system fight infection and other diseases, such as cancer

Lymphatic System

• also helps in both innate and adaptive immunity by filtering the circulatory fluid to remove the pathogens and returning the fluid back to the circulatory system

• this system is made up of lymph fluid, nodes, and vessels

Lymph fluid

• is a clear one which contain less nutrients and oxygen

Lymph nodes

• house of lymphocytes and macrophages which kill the pathogens found in the circulatory fluid

• travels up to your body to alert the body organs

Adaptive Immunity

• a type of immunity that develops when a person’s immune system responds to a foreign substance or microorganism, such as after an infection or vaccination

• involves specialized immune cells and antibodies that attack and destroy foreign invaders and are able to prevent disease in the future by remembering what those substances look like and mounting a new immune response

Antigen

• is any substance that cause your immune system to produce antibodies against it

Antibodies

• are proteins in the blood plasma which neutralize the effects of antigens

Vaccine

• contains a harmless part, variant, or piece of a pathogen or a weakened microbe

2 kinds of defenses that adaptive immunity uses

1. Humoral Immune Response

2. Cell-mediated Immune Response

Humoral Immune Response

• protects the body from the bacteria and viruses in the blood through the action of antibodies in the blood and lymph

• the antibodies is produced by B-cells, type of lymphocyte

Humor

• refers to the body fluids

Cell-mediated Immune Response

• employs T-cells that respond to pathogens through 3 different actions:

1. Kill infected cells;

2. Promotes phagocytosis by other white blood cells; and

3. Induce B-cells to secrete antibodies

Phases of the adaptive response

1. Primary Immune System

2. Secondary Immune System

Primary Immune Response

• this includes that activation of set of lymphocytes until the action of effectors cells

Secondary Immune Response

• starts another round of clonal selection and production of effectors cells

• produces the effectors cells and antibodies faster and in a bigger magnitude

Antibodies

• are like superheroes of immune system, but they do not kill the pathogens directly

• use different mechanisms in order to do their job, to facilitate the death pf pathogens through phagocytosis or cell lysis

• are proteins that protect you when an unwanted substance enters your body

• produced by your immune system, these bind to unwanted substances in order to eliminate them from your system

• they can induce agglutination of microbes by binding several microbes together

• dissolved antigens float freely in the body fluids, making it difficult for phagocytes to capture them

• string several antigens together to immobilize them and make them easier to target

Cell lysis

• refers to the break down of a cell caused by damage to its plasma (outer) membrane

2 types of immunity

1. Active Immunity

2. Passive Immunity

Active Immunity

• is exhibited when antibodies are produced by one’s own body as a response to antigens

Passive Immunity

• are antibodies that can be passed on one person to another such as breast milk or an immunization

Phagocyte

• destroy foreign cells

• macrophages and dendritic cells

Lymphocytes

• T-cells - divide and group into 2 and the other helps in the battlefield; others remain as a memory cell; activate B-cells

• produce special proteins, find infected cells

B-cells

• create antibodies and clones itself and traps the bacteria

Cytokines

• alert/message to other protectors