Primary Defences

Primary Defences

Examples
1. Skin
  1. a physical barrier
  2. also a chemical barrier
    1. sebaceous glands produce oily sebum which waterproofs and has an antibacterial chemical with a low pH to inhibit microbial growth
  3. can be penetrated by cuts, insect bites and natural boday openings
2. Mucus membranes
  1. these protect body openings eg. mouth, ears, nostrils and genitals
  2. most of them secrete mucus to trap pathogens
    1. the mucus usually contains an antibacterial chemical to slow the muliplication of the bug
3. Tears
4. Blood clotting
their function is to stop the entry of parasites and pathogens
block a huge number of microbes daily
if the primary defences are penetrated, the first response of the body is phagocytosis

Resource summary

	Created by gschristie95 over 11 years ago