immunity Flashcards
(10 cards)
3 layers of human defense
barriers
inflammatory response
adaptive/acquired immunity
Neonate immunity
None, born from sterile environment. Neutrophils and monocytes can’t chemotaxis (move around towards or away). Phagocytes can’t get responses from chemotactic signals about bacteria, fungus, virus. Neutrophils may be stressed and can’t respond.
Very deficient in complement (which compliments the immune system). Classical pathway of complement doesn’t count cuz it’s only the antibody antigen activation and neonates don’t have antibodies So the alternative pathway is used, but neonates are deficient in factor B, which is needed for the alternative pathway. Can develop severe and overwhelming sepsis without transferred maternal antibody Lectin pathway of complement system is also impaired due to low levels of mannose-binding. May also be deficient in some collectins (sugar-recognizing proteins that help the body respond to and recognize microbial threats) and collectin-like proteins Respiratory distress in preterm infants is related to collectin, which provides innate defense against respiratory tract infections.
Hereditary angioedema
Is a hyper activation of all three plasma protein systems, with excess bradykinin production being main cause of vascular permeability. Caused by C1 esterase inhibitor, gene that makes C1 inhibitor protein. Is a genetic defect in C1 esterase inhibitor. C1 protein is essential for reducing blood vessel permeability and preventing excess swelling. Autosomal dominant.
Down syndrome
GERD can cause recurrent respiratory tract infections, due to aspiration of thin liquids.
Inflammatory process, stopping and starting, two ways to activate
Critical for survival, so efficient activation must occur regardless of cause of injury.
The biochemical mediators are so potent and potentially detrimental to individual, their actions must be strictly confined to injured or infected tissues. There are three key plasma protein systems essential to inflammatory response-complement, clotting, and kinin. Multiple mechanisms can activate or inactivate the plasma protein systems
Mast cells are likely most important activators of inflammation and are in tissues close to vessels.
Phases of wound healing
1) Inflammation
2) proliferation and new tissue formation or reconstruction
3) remodeling and maturation
Most essential nutrients for wound healing are glucose, oxygen, amino acids
Medications and how they inhibit wound healing
Antineoplastic agents slow cell division and inhibit angiogenesis, NSAIDS delay wound healing and bone formation, steroids prohibit fibroblast migration into wound and delay epithelialization, tobacco smoke delays wound healing and increases risk for infection
Chemotaxis
Directional movement of cells along a chemical gradient formed by a chemotactic factor. Creates a concentration gradient, with higher concentration at target, guiding cells to migrate in that direction Eliciting an inflammatory response requires intercellular communication and cooperation. Examples are complement proteins, bacterial peptides, and chemokines (small proteins that act as signalers to guide movement of cells)
Bacteria resistant to granulocytes
TB, mycobacterium leprae (leprosy), salmonella typhi (typhoid fever), brucella abortus (brucellosis), listeria monocytogenes (listeriosis) can remain dormant or even multiple inside macrophages
Systemic vs local changes
Systemic are fever, leukocytosis, and plasma protein synthesis
Local is heat, redness, swelling, pain possible loss of function
Symptoms include somnolence or drowsiness, malaise, anorexia, muscle aches
