<span>The common cold is regarded a viral.
Viruses: are the source of well-known diseases (colds, conjunctivitis, nasopharyngitis, bronchitis acute, flu, gastroenteritis, measles, mumps, chickenpox, <span>herpes)</span></span>
Could you elaborate more please? (:
Epithelial tissue covers the body surface and forms the lining for most internal cavities. The major function of epithelial tissue includes protection, secretion, absorption, and filtration. The skin is an organ made up of epithelial tissue which protects the body from dirt, dust, bacteria and other microbes that may be harmful. Cells of the epithelial tissue have different shapes as shown on the student's worksheet. Cells can be thin, flat to cubic to elongated. Cited from: https://www.msnucleus.org/membership/html/k-6/lc/humanbio/4/lchb4_3a.html
Photoplethysmography is used to track of heart rate during a workout