The immune system
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

The Immune System PowerPoint PPT Presentation


  • 67 Views
  • Uploaded on
  • Presentation posted in: General

The Immune System. The Skin. 1 st line of defense: physical barrier Oils & sweat destroy some pathogens Some cells burst Some cells shrivel. Mucus Membranes. Coat the openings of the body Nose, mouth, ears, eyes, genitals, anus Lined with cilia & sticky fluids to trap pathogens.

Download Presentation

The Immune System

An Image/Link below is provided (as is) to download presentation

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.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The immune system

The Immune System


The skin

The Skin

  • 1st line of defense: physical barrier

  • Oils & sweat destroy some pathogens

    • Some cells burst

    • Some cells shrivel


Mucus membranes

Mucus Membranes

  • Coat the openings of the body

    • Nose, mouth, ears, eyes, genitals, anus

  • Lined with cilia & sticky fluids to trap pathogens


  • White blood cells

    White Blood Cells

    • Job: Search & destroy

    • Phagocytes: surround & engulf invaders

      • Phagocytosis

    • Lymphocytes:

      • T cells: destroy infected body cells

      • B cells: Inactivate invaders


    Defense proteins

    Defense Proteins

    • Complimentary Proteins

      • Weaken cell membrane

      • Attract phagocytes

      • Cause microbes to stick to wall of blood vessel


    Defense proteins1

    Defense Proteins

    • Antibodies

      • Made by B cells

      • Bind to cell membrane of pathogen

      • Prevents pathogen from binding to host cells

      • Causes pathogens to clump

        • More susceptible to phagocytes

    • Weakens the cell membrane

      • Causes them to burst


    Defense proteins2

    Defense Proteins

    • Interferon

      • Produced by virus infected cells

      • Stimulates uninfected cells to create infection preventing enzymes


    Vaccination

    Vaccination

    • Prevents infections (not a cure)

    • Memory cells developed without actually getting the disease

    • Vaccine

      • Contains antigens of a pathogen

      • Weakened pathogen is injected

      • Stimulates the production of memory cells

    • Speeds up immune response if you encounter the unweakened virus


    Pathogens

    Pathogens

    • Defined: microorganisms that cause disease

      • Viruses: turn cells into virus making factories

      • Bacteria: prokaryotes that can release toxic chemicals

      • Fungi: pierce cells and absorb the nutrients

      • Protozoans: single cells protista (eukaryotes)

      • Parasites: grow and feed on a host


    Pathogens contd

    Pathogens (contd)

    • Some carried by wind, water, direct contact, indirect contact…

    • Some carried by vectors

      • Vector: object that carries a pathogen

      • Examples:

      • Malaria – mosquitos carry the protozoan

      • Black Death – carried by flea’s of mice

      • West Nile Virus – carried by birds, but spread by mosquitos


  • Login