Unit 4: immunology; first and second line of defense

Question 1

first line of defense (non specific) common to everyone

Answer 1

Intact skin
Mucous membranes and their secretions
Chemical factors
Normal flora

Question 2

physical barriers

Answer 2

Skin, mucous membranes, mucus, hairs, cilia, tears, saliva, urine, vaginal secretions, epiglottis

protects the external body

Question 3

chemical factors

Answer 3

Gastric juice, acidic pH of skin, components of sweat, lysozyme (an enzyme found in saliva, tears, mucus, breastmilk)

Destroys pathogens

Question 4

normal flora

Answer 4

Microbes that establish fairly permanent residence but do not cause disease under normal circumstances

Question 5

second line of defense (non specific) common to everyone

Answer 5

Phagocytes and natural killer cells
Inflammation
Fever
Antimicrobial substances

Question 6

phagocytes

Answer 6

Phagocytes are white blood cells that can engulf pathogens
When monocytes enter into tissue spaces, they become macrophages
Neutrophils, basophils, eosinophils can also carry out phagocytosis

Question 7

natural killer cells

Answer 7

type of lymphocyte that recognizes and KILLS infected body cells

Question 8

inflammation

Answer 8

events to respond to injury to destroy invading pathogens, prevent spreading of infection, and to begin repair

• Caused by histamine (chemical in body)
• Redness, swelling, pain, heat (and loss of function in severe cases)

Question 9

fever

Answer 9

Hypothalamus sets body temperature:~ 37°C
* Pathogens and cytokines cause release of prostaglandins which reset the hypothalamus to an abnormally high body temperature
* Elevated temperature inhibits growth of bacteria
* Speeds up many body reactions for faster healing of the body

Question 10

antimicrobial substances

Answer 10

After injury, these substances are produced by our cells to kill any invading pathogens
* ex. complement system
* Proteins that act in a cascade, meaning that one reaction triggers another which triggers another (for amplification helps with complement proteins)

Question 11

adaptive immunity -specific, unique to each individual

Answer 11

Specialized lymphocytes: T cells and B cells
* Antibodies

Question 12

adaptive immunity antigens

Answer 12

Antigens – substances that can trigger an immune response
Example: protein found on the surface of the cell

Usually antigens located on pathogens are different from those located in humans

Antibodies bind to antigens that are specific for each other. (eg. like two puzzle pieces)