first line of defence

Question 1

what is the first line of defence

Answer 1

natural barriers

Question 2

give some examples of natural barriers

Answer 2

1) ears
2) skin
3) respiratory tract
4) eyes

Question 3

how are ears a natural barrier

Answer 3

produces wax which traps pathogens and lysozymes

Question 4

how does the skin act as a natural barrier

Answer 4

1) outer epidermis made up of dead keratinised cells which act as a physical barrier to pathogens
2) skin flora consists of commensal bacteria which competes against pathogenetic bacteria

Question 5

how does the respiratory tract act as a natural barrier

Answer 5

1) ciliated cells which waft mucus to top of trachea, mucus is the swallowed and passed into stomach acid destroying pathogens

Question 6

how do ciliated mucus membranes act as natural barriers

Answer 6

located in the guy, genital and respiratory passages the mucus lines the passages trapping pathogens

Question 7

how do eyes act as natural barriers

Answer 7

produce tears which contain antibodies and lysozymes