Battle Scars Video Questions

What are the 5 main groups of human pathogens? Name a disease caused by each.

1. Bacteria → causes pneumonia

2. Viruses → causes colds & influenza

3. Fungi → causes ringworm

4. Protozoans → causes malaria

5. Macroscopic parasites → causes severe damage to human tissue (ex. roundworms)

What are the ways pathogens gain entry to the body?

• Through any of the body’s natural openings

• With food (can be covered with bacteria, viruses and fungal spores → carried into the gut) 

• Via lungs, ears, urinary openings

• Transmitted from sexual partners into our reproductive system

• Enter openings in skin (pores & follicles, surface wounds)

What is the first line of defense and how does it function?

• The body’s external barriers: skin, membranes, 

• Are non specific

• Bar the entry of ANY pathogen or foreign antibody

Why the second line of defense called “non-specific”?

Because it reacts the same way to any foreign particles that invade the system.

What is inflammation?

• coordinated processes that help contain an infection, destroy pathogenic agent, and initiate repair of damaged tissues.

• Chemical signals released by rupture of skin cells cause an almost immediate increase in blood flow to the area 

  • This is what gives an infection site inflammation

• Increased blood flow creates a local build up of cells that are able to consume invading bacteria

What are the 5 types of leukocytes?

1. Neutrophils

2. Eosinophils

3. Basophils

4. Monocytes

5. Lymphocytes

What are the functions of complement proteins?

• Help the second line of defense identify and eliminate invaders

• (Some) attract phagocytes to the area where bacteria are located

• (Some) deposit a coat around the bacteria that makes it easy for phagocytes to identify them

• (Some) break down their outer membranes, causing the bacteria to lyse or rupture

What are the classes of the immune responses in the body?

1. Blood- based immune response (aka humoral antibody response) 

• Involves B cells (made/mature in bone marrow)

2. Cell-mediated immune response 

• Involves T cells (made in bone marrow, mature in thymus)

What 2 types of cells do B cells differentiate into? What are their functions?

1. Plasma cells- produce antibodies and release them into the bloodstream; short life

2. Memory cells- retain or remember an image of the characteristics of the antigen that has triggered off the latest response; can accelerate immune reaction during second encounter by producing the right antibodies (and more memory cells) and active B cells ← can remain in lymph tissue for long period of time (many present for lifetime)

What does “antigen” stand for?

“Antibody generator”

What do antibodies do?

• Circulate throughout the body in the blood and other body fluids and seek out these specific antigens that caused them to be produced. 

• Then, they bind to the antigen and deactivate it.

  • After binding, the antigen has effectively been labeled → making it easier for cells (like phagocytes) to find and destroy it

What are the types of T cells? What are their functions?

Influence or regulate the way B cells function!

• Helper T cells- (F) help other lymphocytes provide completely efficient immune function ; stimulated to act by the presence of an antigen on an APC

• Suppressor T cells- (F) regulate the immune system to prevent over-activation and autoimmune disease

What does an antigen-presenting cell do?

• Found in most tissues

• Are not antigen-specific

• Can carry fragments of any antigen

What “problem” does clonal selection theory help explain?

How could it have millions of antibodies standing by, just waiting on the off chance that a particular antigen will invade their territory?

clonal selection theory- when an immune cell encounters an antigen —> it multiplies and creates copies of itself to fight infection

What is acquired immunity?

After having been exposed to a particular pathogen, the body makes antibodies to defend it against the effects of the pathogen. After the initial infection, the person is able to resist further infection by the same pathogen.

What is a vaccine and what kind of immunity does it create in the body?

• Vaccines contain pathogens such as viruses or bacteria that have been treated so that they can no longer cause the disease that their presence would normally initiate. 

• Induced Active Immunity- the body has been induced to produce antibodies without becoming infected