The Immune System Concept 43.1- In innate immunity, recognition and response rely on shared traits of pathogens. Dion Kevin Luke Leary Rachael- catherine hartnett. Introductory Video. http://www.cleanvideosearch.com/media/action/yt/watch?v=Nw27_jMWw10. Overview.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Insects rely on the chitin in their exoskeletons as well as in their intestines for the first line of defense
Lysozyme, an enzyme that digests microbial cell walls, as well as low pH in digestive system aid in the first line of defense
Hemocytes, immune cells in insect blood (hemolymph), carry out phagocytosis
Other hemocytes stimulate chemical production and antimicrobrial peptide production
Antimicrobial peptides circulate and disrupt the membranes of fungi and bacteria
Immune response cells rely on identification of unique molecules on invader surface layers
Ex: pg 932
Barrier defenses-Barrier defenses are the typical front line against pathogens.
Skin, Mucous membranes, tears, etc.
Beyond the role of blocking pathogens from the body many create a pathogen killing environment for toxins.
Cellular Innate defenses
Toll-like receptors-recognizes molecule fragments of pathogens
Neutrophils- phagocytic cells which engulf pathogens
Macrophages- Large phagocytic cells which engulf pathogens efficiently. Most common in lymphatic organs
Eosinophils-fight multiple cell invaders such as parasites. Release enzymes to kill invaders
Dendritic Cells-stimulate tissues to develop an acquired immunity
Peptides and proteins work to fight and destroy pathogens.
The body fights pathogens in many other ways such as through inflammation Natural Killer cells.
Several pathogens have developed certain mechanisms that allow them to avoid destruction by pathogenic cells.
In order to do this, for example, the outer capsule that surrounds the bacteria hides the polysaccharides of their cell walls, which prevents recognition.
However, for bacteria that are unable to avoid recognition, some develop resistanceto breakdown by lysosomes. An example of this is Tuberculosis(TB). Instead of being destroyed, microbes grow and reproduce, hidden from immune defenses of the body.