Innate Immunity

Question 1

What are some cellular defenses and their function?

Answer 1

• Phagocytic cells:

• Neutrophils
• Macrophages: move through body, live in organs
• Dendritic cells: stimulate development of adaptive immunity
• Eosinphils: release destructive enzymes against parasites
• Natural cell killers: innate defense circulates the body, detects weird cells, release chemicals which kills said infected cells,

Question 2

Local Inflammatory Response

Answer 2

• Molecules released after injury
• Causing build-up of heat and swelling
• Signalling molecules call neutrophils to site
• Neutrophils release histamines
• Histamines cause vasodilation
• Increase in blood supply produces inflammatory response
• Cycle of signal and response continues
• Blood flow delivers antimicrobial peptides
• Results in pus and excess fluid, which form a lymph
• Fluid transported by lymphatic system
• Lymph nodes with macrophages engulf pathogen entering lymph
• Dendritic cells stimulate adaptive immunity response

Question 3

Systematic and chronic inflammation

Answer 3

• Cells of damaged tissue secrete molecules
• Stimulates release of neutrophils
• WBCs no increases severalfold
• Response includes fever,
• Pathogen activates release of substances from macrophages
• Body’s thermostat rests temp
• Enhances phagocytosis and accelerates tissue repair

Question 4

How do pathogens evade innate immunity?

Answer 4

• Outer capsule prevents destruction

* By preventing molecule recognition and phagocytosis

Question 5

What are the some barrier defences of the human body and what are their functions?

Answer 5

• Skin, mucous membrane,
• Mucous: traps dirt and dust and allows for removal of substances
• Body fluids: hostile to microbes
• Low ph of skin, digestive juices prevent growth of bacteria