Mod 2- Mechanism of Defense & Repair

2nd Line — Innate Immunity 

• Non-specific → responds to many/all types of antigens 

1st Line — Physical/Chemical Barriers 

• Skin + mucous membranes → physical barriers 

• Chemical factors 

• Normal microflora → help prevent harmful organisms from growing 

3rd Line — Adaptive Immunity 

b and t lymphoytes

fight parasites; involved in allergies

eosinophils

enter tissues and become macrophages 

monocytes

destroy infected or abnormal cells

nk [natural killer] cells

rapidly attack/engulf pathogens (phagocytosis)

neutrophils

where are mast cells found

stromal tissues

where are dendritic cells found

epidermis, dermis, mucous membranes 

where are macrophages found

travel through lymphatic system, bloodstream, and tissues 

programmed cell death

apoptosis

what does PMN stand for

• Polymorphonuclear leukocytes 

another term for neutrophil

PMN

PMN function

Find, engulf, and destroy pathogens and damaged tissue.

Microvasculature

microscopic blood vessels within tissues

arterioles function

regulate blood flow into capillary beds

capillaries function

site of nutrient/waste exchange blood and tissues

venules function

drain blood awya form capillary beds towards heart

define inflammation

how tissues react to injury/infection that causes tissue damage. 

• Occur in vascularized tissue [tissue with blood supply] 

what is inflammatory response iniated by

stromal cells: mast and fibroblast

what detect injury and start inflammatio [release histamine]

mast cells

fibroblast has 2 functions

inflammation & tissue repair

which line of defense is inflammation in

2nd line of defense - innate immunity

4 process steps of inflammation

1) limit tissue damage

2) prevent spread

3) activate adaptive immunity

4) start wound healing

5 signs of inflammation

redness, heat, swelling, pain, loss of function

another term for redness

erythemaa

another term for swelling

edema

edema

increase in interstitial fluid

mast cell degranulation

Fast/immediate release of chemicals already made and stored 

3 types of mast cell chemicals

histamine, chemotactic, cytokines

mast cell synthesis

Slower release of NEWLY made chemicals 

where is mast degranulation chemicals stored

granules

where is mast cell synthesis stored

made after activation

PLA₂ = phospholipase A₂ [enzyme] is part of mast cell synthesis; what does it do?

break apart cell membrane phopholipid to fomr new several proinflammatory chemicals so inflammation occur

histamine causes 2 things

active hyperemia

blood vessel become more permeable

neutrophil function

engulf and kill microbes

• first responser

macrophage function

released by monocyte + clean debris

platelets function

blood clot - hemostasis

rbc function

stabilize clot and gets trapped in fibrin

plasma protein meaning

protein systems in blood activated

3 characteristics of protein systems

initially inactive

made by liver

carried in blood plasma

injury site: become become active enzymes—

complement proteins

destroy germs; bacteria and yeast, ag-ag

coagulation proteins

stop bleeding; clot

kinin proteins function

weak histamine effects - cause pain and inflammation

in vascular response:smooth muscle- arterioles, what is the main exchange

smooth muscle relax → vasodilation

increase blood flow = redness + heat

in vascular response:smooth muscle- capillaries, what is the main exchange

Endothelial cells contract , ↑ permeability → edema 

in vascular response:smooth muscle- venue, what is the main exchange

endothelial cells contract and a gap forms

increase permeability →  edema + WBC entry

what are the 2 pressure control fluid movement that filtrate

BHP- blood/capillary hydrostatic pressure:

IFOP- interstitial fluid osmotic/oncotic pressure :

what are the 2 pressure control fluid movement that reabsorption

BCOP- blood capillary osmotic pressure:

IFHP- interstitial fluid hydrostatic pressure

BHP- blood/capillary hydrostatic pressure: function

PUSHES fluid out of blood into tissues

IFOP- interstitial fluid osmotic/oncotic pressure :function

The proteins in the tissue PULLS water OUT of the blood and INTO the tissue.

BCOP = Blood/Capillary Colloid Osmotic Pressure function

plasma proteins [na+ and albumin] pull water back into blood

IFHP = Interstitial Fluid Hydrostatic Pressure  function

The fluid in the tissue creates pressure that helps push fluid toward the blood vessel

hydrostatic pressure

Pushes fluid away from where the pressure is

osmotic pressure

chemicals/proteins pull water

oncotic pressure

proteins pull water

edema

excessive fluid buildup in interstitial tissue spaces

when does edema occur

during vascular response of acute inflammation

edematous

tissue with extra fluid

what % is needed before swelling is noticeable

30%

what is third spacing

when intravascular - blood goes into tissue

what is ascites

fluid buildup in abdominal cavity

what does anti histamine block and result

histamine, decrease inflammation

what does NSAID block and result

COX → ↓ PGs
↓ pain + inflammation

what does corticosteroid block and result

PLA₂ → ↓ PGs + LTs

Strong ↓ inflammation 

what does asipirin block

COX and TXA₂

COX function

help produce PG [prostaglandins] which help with pain, inflammation, swelling

TXA₂ function

help platelet stick together

what does ibuprofen block

COX pathway

what does corticosteroids block

Block PLA₂