{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

bio 315 chapter 15 - Chapter 15 Infection and Disease Part...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 15: Infection and Disease Part 3: Microorganisms, Humans, and Disease Infection & disease General Terms & Principles If a microorganism or other agent (like a virus) has the capability of causing disease, we call it a pathogen . Infection refers to the successful invasion and growth of pathogens in the body. Disease refers to an abnormal state in which the body or one of its parts is incapable of performing its functions properly. An organism is said to have a disease when a pathogen overcomes the body’s defenses. (In other words, it’s possible to come into contact with pathogens and even have an infection without ultimately having a disease.) A host is an organism that shelters and/or supports the growth of pathogens. Disease caused by infective pathogens is referred to as “ infectious disease ” (as opposed to “degenerative”). Pathology Pathology is defined as the study of disease in an individual, and deals with… o Etiology (the cause of disease) o Pathogenesis (the development of disease over time in an individual) o Effects/treatments of disease The Normal Microbiota –Microbes That are “Supposed” to be There What is their normal relationship to a host organism? Humans (and other animals) are usually sterile before birth, after which they become colonized both internally and externally. Microbes that establish permanent residence either inside or on the body surface without causing disease are the normal microbiota (also called the resident flora). Unbelievably, it is estimated that the resident population of microbial cells outnumbers human cells by a factor of 10! Also, the normal microbiota contains members that are bacteria, fungi, and protozoa. Examples: o Gastrointestinal tract: Escherichia coli
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
o Oral cavity (mouth): Various Streptococcus species o Skin: Various Staphylococcus species o Vaginal area: Lactobacillus, Candida (a yeast) It’s a Symbiotic Relationship (usually mutualistic) Example – E.coli. It gets a warm environment with free food; what do we get?
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern