Using the three lines of defense explain what could happen if a pathogen enters a human body?

Is Cordyceps Sinensis safe to use? How do you stop lucid dreaming? What is insertion rule? I have a root canal but want to take out the root canal? What is located anterior to the esophagus and carries air to the bronchi? Can a woman have testes? Im pregnant and sleeping all the time is something wrong I mean It's scaring me Ive heard of women having no energy in pregnancy but this seems extreme. help please? What is health promotion? What are some prenatal tests for Spina Bifida? Which hormone is associated with the maintenance of the placenta? Can you run tpn with blood? How are van eyck pieter bruegel and peter paul rubens related? Why do animals that reproduce through internal fertilization produce fewer eggs than those that reproduce through external fertilization? What are the symptoms of aConus Medullaris problems? Without what can skeletal muscles contract in some reflex actions? I am sixteen years old and my nipples haven't harden yet is that normal? What do you call someone from Corfu? What other options do 16 year olds have besides going to jail? What are the symptoms of pneumonia? Is the Buffy coat made up of white blood cells and platelets?