NURS 116 Lecture Notes - Lecture 5: Stratified Squamous Epithelium, Mucus, Tears
Document Summary
Immunity: a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Non-specific immunity ( innate ) protective fxn that we are born with; works w/o previous exposure; non specific barriers or eliminators of pathogens. First line of defense: intact skin, mucous membranes + secretions; passive and. Second line of defense : nk cells, phagocytic wbc, macrophages; inflammation, localized, present at body inner or other surfaces fever, antimicrobial substances; active, present inside blood or body tissue. Specific immunity (adaptive) acts through specifically recognizing a pathogen that breached innate immunity. Third line of defense: specialized lymphocytes t and b cells; ab. Physical barrier = skin and mucous membrane. Skin contains keratins (water resistant, harder tissue made of fibrous tissue), which grow from skin and are fibrous proteins, tough, insoluble as a major physical defense of skin; stratified squamous epithelium that is keratinized. Mucous membranes are linings of body cavities and internal organs.