Innate Immunity
1. Describe the composition, function, and the purpose of physical, mechanical, and biochemical barriers, The first line of defense against damage and infection is composed of tightly associated epithelial cells including those of the skin and the mucous membranes of the GI, GU, and respiratory tracts. The highly interconnected mucosal epithelial cell junctions prohibit the passage of microorganisms. Many infectious microorganisms are mechanically cleansed from the surface during vomiting, urination, coughing or sneezing. Additionally the skin temperature inhibits microorganisms because they prefer temperatures near 37 C for more efficient growth. Epithelial surfaces also provide biochemical barriers by synthesizing and secreting substances that trap or destroy microorganisms . Mucous, perspiration, saliva, tears, and earwax are all examples of biochemical secretions that trap and kill potential disease-causing Module 3 INNATE IMMUNITY; Objectives 1 – 4 Describe the composition, function, and purpose, of physical, mechanical, and biochemical barriers: The first line of defense against damage and infection is composed of tightly microorganisms. Sebaceous glands in the skin secrete antibacterial and antifungal fatty acids and lactic acids. Perspiration, tears and saliva contain enzymes (lysozymes) that attack cell walls of gram (+) bacteria. 2. Discuss the characteristics of inflammation, relating those to the observed clinical manifestions of inflammation, i.e. redness, heat, swelling, pain and loss of function. Inflammation is usually initiated by cellular injury. Clinical manifestations are the result of vascular changes and the subsequent leakage of circulating components into the tissue. Heat and redness are the result of vasodilation and increased blood flow through the injured site Swelling occurs as exudate (fluid and cells) accumulate. Pain is caused by pressure