6.6 Could the infections have been prevented?

Question 1

Skin flora

Answer 1

The large numbers of harmless
microbes that live on the skin surface. These
bacteria are well adapted to conditions on the
skin and through successful competition prevent
colonisation by other bacteria.

Question 2

Mucus, Mucous

Answer 2

A thick slimy fluid secreted by
the cells lining many organs. Mucus is produced,
for example, by cells in the gas-exchange
system, the digestive system and the
reproductive system. Apart from water, its main
component is a protein called mucin. Mucus
acts as a lubricant and as a protective layer.

Question 3

Cilia, Ciliated, Cilium

Answer 3

Tiny hair-like extensions
(singular cilium) of the cell surface membrane.
Ciliated epithelial cells line the airways of the
lungs. Small particles of dust in the air we
breathe in are trapped in the mucus that lines
these airways. The beating action of the cilia continuously wafts this mucus and the trapped
particles up into the throat where it is
swallowed. Ciliated epithelial cells also waft egg
cells down the Fallopian tube from the ovary to
the uterus.

Question 4

Lysozyme

Answer 4

An enzyme found in tears, saliva and
other secretions which kills bacteria by
breaking down their cell walls.

Question 5

Herd immunity

Answer 5

If a large proportion of the
population is vaccinated against a particular
disease, it is unlikely that the disease will be able
to spread from one person to another. Even those
who did not receive the vaccine will get some
protection. This protection is referred to as herd
immunity.

Question 6

Active artificial immunity

Answer 6

Immunity that
develops following immunisation. Antigens in
the vaccine trigger a specific immune response
by the body’s immune system.

Question 7

Passive artificial immunity

Answer 7

The type of
immunity that develops when a person is given
ready-made antibodies; their own immune
system does not make them. This method
provides immediate protection in emergency
situations but is short-lived. The protein
antibodies are broken down after a few days or
weeks.

Question 8

Passive natural immunity

Answer 8

The type of
immunity that develops when antibodies pass
from a mother to baby either across the placenta
before birth, or via breast milk after birth. This
helps protect the baby for a short time.

Question 9

Active natural immunity

Answer 9

Immunity that
develops following an infection. The specific
immune response to the foreign antigens helps
to destroy the pathogens and produces a supply
of antibodies and B memory and T memory
cells that will respond quickly if re-infected with
the same pathogen.