If blood contains low numbers of
platelets it will clot slowly
If it gets through
immune system kicks in
Immune system
White blood cells
Travel around the blood
Patrol for microbes
Invading a microbe
Consuming them
Engulf foreign cells and digest them
Producing antibodies
Every invading cell has unique
molecules called antigens on its
surface
Starts producing proteins called antibodies when
they come across a foreign antigen they lock onto
and kill invading cells- specific to the type of
antigen
Produces antibodies rapidly and
carries them around the body to kill
similar bacteria or viruses
If infected again the white blood
cells will produce antibodies and
become naturally immune to
the pathogen
Producing antitoxins
Counteract toxins
produced by
invading bacteria
Semmelweiss
Women were dying in huge
numbers after childbirth from a
disease called puerperal fever
He believed it was
doctors spreading
the disease as their
hands were
unwashed from
when they treated
other patients
Doctors were
made to
wash their
hands in an
antiseptic
solution and
the death
rate dropped
by 10%
Antiseptic solution killed the
bacteria on doctors' hands. There
was no proof of this so his method
was dropped when he left the
hospital and death rates rose again
Nowadays we have basic
hygiene, education and new
drugs to control disease