TEAS - THE IMMUNE SYSTEM

what is the function of the immune system?

protects the body from pathogens

what are pathogens?

bacteria, virus, fungi, parasites, toxins

bone marrow

where white blood cells (leukoctyes) are produces and B cells mature here

where do B cells mature?

bone marrow

where are white blood cells produced?

bone marrow

where do T cells mature?

Thymus

what is the function of the spleen?

filters blood, destroys old red blood cells, and stores white blood cells

what is the function of the lymph nodes?

filter lymph fluid and trap pathogens

what is the function of the lymph vessel?

carry lymph fluid (contains immune cells and waste)

what are the two types of immunity?

innate and adaptive 

what is the bodys first line of defense?

innate immunity

what are some characteristics of innate immunity

• non specific (defends against a broad range of pathogens)

• fast response time

• no memory

what are phagocytes?

immune cells that patrol the body looking for invaders, engulf pathogens and break them down using enzymes and respond quickly to foreign threat (ex: macrophages, neutrophile, dendrite cells)

phagocytosis

process of eating / digesting harmful invaders

macrophages

big eaters, engulf LARGE numbers of pathogens (can also alert T cells)

neutrophils

most common; arrives FIRST at infection site, fast responders

which phagocytes arrives first at infection sites?

neutrophils

dendrite cells

capture pathogens and help activate the adaptive immune system by presenting antigens to T cells

what is the body’s second line of defense?

adaptive immunity

what are characteristics of adaptive immunity?

• specific (targets specific pathogens using antigens)

• slower at first, but faster upon 2nd exposure

• has memory

which immunity involves B and T cells?

adaptive immunity

B cells

produces antibodies that bind to specific antigens

helper T cells

activate B cells and other immune cells

cytotoxic T cells

kill infected cells

what are the two types of adaptive responses?

Humoral and cell-mediated response

what is the Humoral response?

• uses B cells and antibodies

• targets pathogens in body fluids (not inside cells)

what is the Cell-mediated response?

• uses T cells (especially cytotoxic T cells)

• targets infected or abnormal cells

what are Natural Killer cells?

cells that attack infected / cancerous cells (innate immunity)

what are interferons?

proteins that stop viral replication

what do helper T cells do?

activate B cells and other T cells (activate everything)

what do Cytotoxic T cells do?

kill infected or cancerous cells

what do memory T cells do?

remember pathogens for faster future responses

what do regulatory T cells do?

 prevent overreaction of the immune system

what do plasms B cells do?

make antibodies

what do Memory B cells do?

store info about past infections

what are antigens?

foreign substance that triggers and immune response

• Found on surface of pathogens 

• Function is to act as a “flag” or “marker” that tells the immune system it doesn't belong

(antigen = bad / found on pathogen)

what are antibodies?

a protein made by B cells that binds to a specific antigen

• Function is to bind to a antigen to neutralize it or mark it for destruction by other immune cells (also called immunoglobulin / Iga)

(antibody = good / from B cells)

what are the four types of immunity?

1) active natural

2) active artificial 

3) passive natural

4) passive artificial

active = you make it / passive = you receive it

what is Active Natural immunity?

body makes antibodies AFTER infection (ex: chickenpox recovery)

what is Active Artificial immunity?

body makes antibodies after vaccination (ex: flu shot)

what is Passive Natural immunity?

antibodies form mother to baby via placenta or breast milk (ex: newborn immunity)

what is Passive Artificial immunity?

antibodies infected into the body (no memory formed) (ex: antivenom). Gives immediate but short term protection

what are vaccines?

stimulates immune system to make memory cells

what is a autoimmune disease?

 immune system attacks body's own cells (ex” lupus, type 1 diabetes)

what is an allergy?

overreaction to harmless pollen

what is an immunodeficiency?

weak or absent immune response (ex: HIV / AIDS)

what is histamine?

a chemical that causes inflammation and swelling

what does HIV do to the immune system?

HIV destroys helper T cells which weakens the entire immune system