Section outline


  • Hi everyone!

    Today, we’ll begin by looking at the first line of defense, the body’s outermost protection system. This line is your body’s “security guard,” working 24/7 to block harmful invaders like bacteria, viruses, and parasites before they can enter your body. It includes physical barriers like skin, and chemical barriers like the enzymes in your saliva or the acid in your stomach. These defenses don’t target specific pathogens—they simply aim to stop any foreign substance from getting in.

     

    11.1 Topic Learning Outcome
    By the end of this lesson, you will be able to:
    11.1.1 List the types of physical and chemical barriers.
    11.1.2 Describe how these barriers prevent pathogen entry.
    11.1.3 Identify parts of the body involved in the first line of defense.

    11.2 List of Subtopics
    11.2.1 Physical barrier
    11.2.2Chemical barrier
    11.2.3 Commensal bacteria


    11.3 Video Lecture 




    11.4 Lecture Slide

    Scroll the accompanying lecture slides for further details.