Human Defence Systems Against Pathogens | Health | Biology | FuseSchool

Human Defence Systems Against Pathogens | Health | Biology | FuseSchool Pathogens are disease causing microorganisms, that our body has many defence mechanisms against. The skin is the first physical barrier, providing a protective layer that is hard to penetrate. We also have sebaceous glands that secrete acids, thus preventing the growth of pathogens. Pathogens can enter through our mouth, nose and eyes quite easily. Saliva, mucus and tears contain lysozyme enzymes that break down the cell wall of many bacteria. Our respiratory system then has it's own defences from nasal hair to mucus to enzymes. Hydrochloric acid inside our stomach kills many harmful microorganisms that enter in our food and drink. Our blood also has a great defence system; blood contains platelets and fibrin which causes blood to clot and scabs to form, sealing off cuts from the outside. Our blood also has another fantastic weapon; white blood cells. These can hunt down and destroy pathogens, they can ingest them, and they can neutralise the effect of the pathogen toxins on the body. VISIT us at, where all of our videos are carefully organised into topics and specific orders, and to see what else we have on offer. Comment, like and share with other learners. You can both ask and answer questions, and teachers will get back to you. These videos can be used in a flipped classroom model or as a revision aid. Twitter: Access a deeper Learning Experience in the FuseSchool platform and app: Friend us: This Open Educational Resource is free of charge, under a Creative Commons License: Attribution-NonCommercial CC BY-NC ( View License Deed: ). You are allowed to download the video for nonprofit, educational use. If you would like to modify the video, please contact us: Click here to see more videos:

LicenseCreative Commons Attribution-NonCommercial

More videos by this producer