IMM250H1 Lecture 2: Immunology Lecture 2
Document Summary
Plan a: before bacteria gets in (physical constitutive barriers) Plan b: after bacteria gets in (innate response) We are in constant contact with bacteria, and the skin and mucosa surfaces are sites for microbial encounters. The mucosa surfaces are very vulnerable because there is only a 1 cell layer that prevents organisms from coming in. Constitutive basically means that they are pre-existing, so it does not require any push to begin defending. The barriers should not be broken, but obviously, there are microbial that have found ways to enter and mess up our system. Lysozymes dissolve the cell wall of the bacteria. Acidity (stomach) has a ph of 2 and it inhibits bacteria growth. Normal microbiota competes with pathogens for space and nutrition. Skin: squamous epithelium means that there are several layers. The mechanisms is desquamation meaning that it flakes off. Mucous membranes: non-ciliated epithelium (gi tract), ciliated epithelium (respiratory tract), epithelium (nasopharynx).
