These are the most frequently used words in this book.
action
activity
age
although
animals
between
blood
body
bone
brain
called
cases
cause
cells
century
changes
con
conditions
control
death
development
different
disease
drugs
during
early
effects
even
example
eye
female
fibres
first
fluid
food
form
function
further
hand
heart
high
hormones
however
human
important
increase
individual
ing
known
less
level
life
long
may
medical
men
movement
muscle
nerve
new
normal
now
number
occur
often
organs
oxygen
pain
part
patients
people
person
physical
pressure
process
result
see
sexual
since
skin
small
social
state
study
system
term
thus
time
tion
tissue
two
types
use
used
usually
water
women
work
world
years