C3.2 Defense Against Infectious Disease (Immune System) Flashcards
What is a pathogen?
-biological agent that causes disease
-cellular pathogens: helminth, protozoa, fungi, bacteria
-acellular pathogens: viruses, prions
What is an antigen?
-immune system can recognize body cells “self” vs foreign material “non-self”
-“non-self” markers are glycoproteins(antigens)
What is the primary pathogen defense?
-surface barrier protection
-skin, hair, eyelids
-mucus membranes, cilia(respiratory system)
-chemical protection: stomach acid, lysozyme in tears
What is innate immunity?
-the second line of defense against infection that are non-specific cellular and molecular responses and does not change over time
-phagocytic leukocytes will migrate and engulf the foreign pathogens via phagocytosis
-presents as inflammation, fever, and activation of antimicrobial proteins
What are T-Cells?
-produced in the bone marrow
-stored in the thymus gland
-seeks intruder, identified by antigen (glycoprotein)
-helper T-Cells identify pathogen from antigen presenting cell (APC)
-killer T-Cells kill cells with invading microbes
-suppressor T-Cells end killing spree
-memory T-Cells remember antigens
What are antibodies?
-Y shaped proteins that target specific invaders
-their shapes are similar only differing in end arms
-the arm would be shaped specifically to match the antigen marker
-an antibody attached to an antigen produces a larger entity
-make microbe easily identifiable to macrophages, which engulfs them
What are B-Cells?
-produced and released from the bone marrow
-make the antibodies (specific immunity) based on information received by helper T-Cells
What is the immune response?
-macrophages scavenges for microbes and when overpowered they contact the helper T cells
-the helper T cells identify the antigen and cells in the B cells
-the B cells produce antibodies which attach to the antigen marking it
-killer T cells go after the host cell or bacteria to kill it
-macrophages eat it up
-suppressor T cells break up the mess
-macrophages clean up the debris once again
What are vaccines?
-weakened/killed pathogens or mRna for antigen protein is injected into the body
-immune response is activated toward antigen and is able to kill the pathogen
-memory of antigen is retained by memory T and B cells so when the body is exposed to the real pathogen, sickness does not occur
What are antibiotics?
-block processes that occur in prokaryotic cells but not eukaryotic cells
-a virus has no metabolism so it’s not affected
-some bacteria have evolved with genes that offer resistance to antibiotics, some have many
-do not eat antibiotics like skittles
What is an autoimmune disease?
-it is where the system incorrectly attacks healthy cells
-example: arthritis, multiple sclerosis
What is HIV?
-virus reduced lymphocytes and causes a loss in ability to produce antibodies thus causing AIDS
What is cancer?
-normal cells mutate and
replicate out of control
What is tuberculosis?
-bacteria in cattle related to the human variant and can cross the species barrier
-affects the lungs and causes a cough with bloody mucus
What is zoonoses?
-infectious disease that can be transmitted from other species to humans
-transferred directly from the non-human host or may be transmitted by an unaffected intermediate species, vector
