CHAPTER 15 Flashcards
What is immunity?
ability to ward off disease
What is susceptibility?
lack of resistance to a disease
What are the 2 kinds of immunity?
Innate, natural defenses and adaptive immunities
What are innate, natural defenses?
present at birth, all body defenses against any kind of pathogen; rapid, provide nonspecific resistance to infection
What is the first line of defense?
any barrier that blocks invasion at the portal of entry, non specific- skin, mucous membranes, antimicrobial substances
What is the second line of defense?
protective cells and fluids; inflammation and phagocytosis, nonspecific- inflammation, fever, phagocytes
What is the first line of defense comprised of?
skin and mucous membranes of the respiratory, digestive, urinary, and reproductive systems
What is the role of epidermis in innate immunity?
multiple layers of tightly packed cells- few pathogens can penetrate, shedding of dead skin cells removes microorganisms, epidermal dendritic cells phagocytize pathogens
What is the role of the dermis in innate immunity?
collagen fibers help skin resist abrasions that could introduce microorganisms
What are the chemicals that the skin has to defend against pathogens?
perspiration- salt inhibits growth of pathogens, antimicrobial peptides, dermicidins, lysozyme destroys cell wall of bacteria, sebum lowers skin pH inhibitory to bacteria
What is the role of the mucous membranes in innate immunity?
line all body cavities to open environment, produce chemicals that defend against pathogens
What is the role of the lacrimal apparatus in innate immunity?
produces and drains tears, blinking spreads tears and washes surface of eyes
What does lysozyme do in tears?
destroys bacteria, degrades peptidoglycan in bacterial cell wall, killing gram positive
What is the role of the microbiome in innate immunity?
competes with potential pathogens, create an environment unfavorable to other microorganisms, prevent pathogens from entering host, promote overall health
What is the role of antimicrobial peptides?
can punch holes in pathogen’s cytoplasmic membrane, interrupt internal signaling or enzyme function, or act as chemotactic factors to recruit leukocytes to site of infection
What is the second line of defense comprised of?
cells, antimicrobial chemicals, and processes
How does plasma act as defense component in blood?
mostly water containing electrolytes, dissolved gases, nutrients, and proteins, serum is fluid remaining when clotting factors are removed, contains iron-binding protein transferrin
What are formed elements and what are the 3 types?
cells and cell fragments in plasma- erythrocytes, platelets, leukocytes
What are erythrocytes?
carry oxygen and carbon dioxide in blood
What are platelets?
involved in blood clotting
What are leukocytes?
involved in defending the body against invaders, divided into granulocytes and agranulocytes
What are granulocytes and what are the 3 types?
phagocytize pathogens; contain large granules that stain different colors, 3 types- basophils, eosinophils, neutrophils
What color do basophils stain?
stain blue with basic dye methylene blue