Chapter 15 (Nonspecific defenses)

Question 1

What do we mean by “nonspecific” defense?

Answer 1

Innate defenses: defenses you are born with

Question 2

Describe the first line of defense.
o What is the main goal?
o Name the physical barriers
o Name the chemical barriers. How do they work?
o What is a mucus membrane? Goblet cells?
o What is microbial antagonism?

Answer 2

Goal: prevent entry of pathogen
Physical barriers: skin, dead skin, dry skin: secretions, fats, acids, salts create hostile environment
Chemical barriers: lysozome (tears, urine, saliva) degrade cell walls, pH of secretions: chemicals that bind iron
Mucous membrane produce mucous → goblet cells & cilia move mucous
Microbial antagonism help stimulate innate defenses in blood

Question 3

Describe the second line of defense?

o What are the components of blood?
 What is “differential white blood cell count”?
* If (enter cell type here) cells are higher than normal, what does that tell you?

Answer 3

2nd line of defense kicks in when pathogens get past 1st line. Occurs in the blood
Blood= plasma (water, electrolytes, nutrients, proteins) + formed elements
plasma 50%, RBC 45% platelets pieces of cells → clotting
INCREASED EOSINOPHILS: helminth -parasitic worm- or allergies
INCREASED TOTAL LUEKOCYTES & NEUTROPHILS: bacterial infection
INCREASED LYMPHOCYTES: viral infection

Question 4

Describe the second line of defense?

o What are the different types of cells involved? What do they do?
 Granulocytes vs. agranulocytes (which leukocytes are which?)
 Wandering vs. fixed macrophages
 Functions of each of the 5 leukocytes

Answer 4

GRANULOCYTES
Basophils (blue)- make & release histamine-cause itchy watery eyes
Eosinophils (red/orange): cause phagocytes & diapedesis (cells leave blood vessels @ site of infection)
Neutrophils (lilac): phagocytes & diapedesis
AGRANULOCYTES
Monocytes: mature into macrophages
Lymphocytes: main cells of the specific immune system also include natural killer cells (nonspecific)
WANDERING MACROPHAGES: diapedesis & move throughout tissues
FIXED MACROPHGES: diapedesis & stay in specific tissues
Never Let Monkeys Eat Bananas

Question 5

Describe the second line of defense?

o Understand the process of phagocytosis (5 stages)

Answer 5

Phagocytosis: engulf & destroy invaders
1) Chemotaxis: movement of cell toward chemical stimuli (waste product of pathogens, PAMPS pathogen associated molecular patterns, flagellin, pili, fimbriae)
2) Adherence: phagocyte sticks to invader -receptors typically bind to PAMP, antibodies, complement proteins
3) Ingestion: pseudopodia extend & surround microbe formation of a phagosome
4) Digestion: phagosome fuses with lysosome “phagolysosome” has reactive oxygen species & pathogen degrading enzyme
5) Elimination: by exocytosis & waste materials dumped outside of cell

Question 6

Describe the second line of defense?

o What is extracellular killing? Who does it? How?

Answer 6

Extracellular killing is killing cells outside of the immune cells

NK cells secrete toxins onto the surface of VIRALLY INFECTED BODY CELLS OR TUMOR CELLS. no harm to the body b/c have MHC type 1 molecule

Eosinophils mainly attack HELMINTHS by attaching to their surface. secrete toxins that weaken or kill organism. Eosinophilia elevated # of eosinophils. MITOCHONDRIAL DNA & secreted proteins combine to attack pathogens

NEUTROPHILS mainly attack BACTERIAL CELLS. secrete oxygen species that kill microbe cells. NEUTROPHIL EXTRACELLUAR TRAPS (NETs): NUCLEAR DNA & cytoplasmic granules combine to trap pathogens. this prevents spread of infection, reactive oxygen species are toxic to microbes, also produce peptides that lyse microbial cells

Question 7

Describe the second line of defense?

o List the nonspecific chemical defenses.

Answer 7

TOLL-LIKE RECEPTORS: bind PAMPs (found in invaders) @ cell membrane
NOD PROTEINS: bind PAMPs inside cell (cytoplasm) stimulates apoptosis, inflammation, interferons
COMPLEMENT: 3 forms of activation (Classic, Alternative, Lectin)

Question 8

Describe the second line of defense?

o What is complement?
 End result?

Answer 8

a series of PROTEINS that come together to make MEMBRANE ATTACK COMPLEX on invader surface
End in complement cascade

Question 9

Describe the second line of defense?

o What cells release interferons?
 What do interferons do?

Answer 9

Released by VIRALLY INFECTED CELLS
Released by IMMUNE CELLS responding to infection
MAIN ACTIONS:
stop TRANSLATION (of viral genome) in cells next to infected cell
Stimulate PHAGOCYTOSIS (help get rid of virus)

Question 10

Describe the second line of defense?

o Describe the symptoms and mechanisms of inflammation.
 Why is this a good thing?
 When is it a bad thing?

Answer 10

SYMPTOMS: redness, swelling, & local pain
MECHANISM: DIALATION blood vessels & increase permeability of blood vessels
GOOD: stimulates migration of phagocytosis by diapedesis. brings defense cells & chemicals, results in tissue repair
BAD: Chronic LONG LASTING (can cause tissue damage & death) lead to loss of limbs

Question 11

Describe the second line of defense?

o Define fever.
 What triggers a fever? (know the general word AND be able to give examples)
 Why is fever a good thing?
 When is it a bad thing?

Question 12

the end

Question 13

Define hematopoiesis

Answer 13

process to make blood cells