Page 3 - 8.4 JOINTS
P. 3
e
w
e
w
e
e
t
t
t
t
l
e
c
h
h
o
l
l
w
l
o
o
n
r
r
h
r
h
me
h
p
e
e
p
a
e
p
s
w
w
w
e
e
e
e
l
e
a
r
r
a
a
mo
mo
mo
r
e
e
T
T
T
e
e
e
r
o
c
o
c
o
o
s
• •The places where two or more bones meet are called
s
h
s
d
c
r
a
e
b
r
r
a
s
h
h
e
h
s
n
a
n
n
a
e
b
b
e
b
e
c
c
c
e
o
o
i
i
s
o
i
e
e
p
p
p
e
l
h
l
l
h
d
d
h
d
h
e
h
h
e
e
e
e
e
o
e
o
o
e
g
g
e
g
t
t
t
t
t
t
r
a
y
y
a
a
a
a
e
a
s
s
s
e
r
r
r
r
y
r
b
e
e
b
b
s
i
T
i
n
l
u
s
i
u
T
s
i
s
T
o
l
e
e
.
t
t
e
s
s
joints. The bones are held together by a special tissue
j
t
t
u
l
s
c a l l e d t h e l i g a me n t .
called the ligament.
e
h
l
e
e
h
a
r
g
e
o
o
o
r
e
c
h
e
r
x
m
o
o
m
m
r
,
r
:
:
:
o
b
b
l
a
o
a
b
a
e
w
e
e
t
t
o
s
r
s
s
d
d
d
e
t
e
e
r
mp
mp
• •For example: our arm bends at the elbow, our legs can
mp
l
e
r
a
r
a
a
t
t
u
t
a
a
e
x
l
l
x
n
s
b
u
r
F
a
n
F
n
n
u
F
u
o
t
t
a
a
t
a
a
a
n
n
o
o
n
u
a
u
u
h
h
c
c
h
r
a
a
r
e
r
c
a
d
d
a
bend at the knee and our head can rotate around our
d
a
e
b
e
e
a
n
d
d
d
d
r
r
r
r
n
u
u
u
o
r
r
o
n
n
o
o
t
t
e
o
o
d
u
u
d
t
d
e
o
r
r
r
e
a
e
e
a
t
a
e
a
k
t
o
n
n
n
n
o
u
h
s
j
u
u
u
s
.
j
s
T
T
s
a
s
c
T
a
j
a
s
s
w
w
w
e
e
k
k
e
k
n
h
h
o
o
o
n
neck. These junctions are known as joints.
n
h
n
r
r
e
n
n
a
a
a
r
e
s
e
s
s
n
e
e
e
e
c
.
i
i
n
c
c
o
.
o
t
i
t
i
k
.
t
n
j
n
o
n
n
o
n
n
t
i
e
• •When bones move at the joints, they rub against each
a
t
b
n
t
i
t
t
e
b
t
n
e
b
h
i
b
b
s
i
i
j
e
e
s
j
j
n
n
n
r
r
r
a
b
n
o
o
o
e
e
e
e
a
e
e
a
W
W
W
s
e
a
,
n
n
a
,
,
h
e
o
o
a
s
a
a
a
e
n
o
n
n
a
a
e
h
h
h
s
mo
v
c
c
mo
c
s
mo
v
y
y
y
t
t
t
v
h
n
s
t
h
h
h
s
t
t
g
h
g
t
s
g
i
h
e
e
t
t
t
e
u
h
u
u
g
s
t
a
a
n
n
a
r
t
t
r
t
o
n
s
s
o
o
g
e
g
g
i
a
i
c
v
c
c
n
n
v
v
e
e
i
o
o
o
a
a
e
e
a
a
e
a
n
t
r
r
g
g
t
r
r
h
h
h
h
a
a
h
a
h
e
e
e
e
u
e
e
.
b
h
u
.
.
f
b
p
b
r
b
r
h
h
h
p
p
h
e
t
r
t
t
t
u
t
t
e
b
e
e
b
h
e
e
b
b
b
k
r
s
i
o
o
e
e
e
t
t
I
other. If the bones kept rubbing against each other over a
o o o
t
k
i
i
o
I
k
I
n
n
s
r
r
n
f
s
f
.
,
g
r
e
t
,
.
r
e
g
v
e
e
v
p
e
e
o
o
u
u
h
h
p
r
w
d
r
w
t
r
l
l
r
d
T
T
t
y
t
o
a
a
y
e
p
e
r
o
e
r
p
u
u
o
o
e
i
o
o
o
e
o
t
f
f
t
i
o
r
e
t
t
n
h
h
w
,
,
w
long period, they would wear out. Therefore, to prevent
e
l l l o n g p e r i o d , t h e y w o u l d w e a r o u t . T h e r e f o r e , t o p r e v e n t
o
d
d
n
e
e
e
n
n
r
a
r
o
r
a
o
e
m
e
e
e
n
f
f
m
o
p
p
o
o
n
a
a
w
w
o
f
e
f
n
n
e
e
h
e
u
r
r
o
f
f
o
e
u
o
e
o
,
s
t
t
t t t h e b o n e s f r o m w e a r i n g o u t , t h e r e i s a p r e s e n c e o f s o f t ,
s
the bones from wearing out, there is a presence of soft,
,
t
t
t
h
t
h
,
,
c
h
c
s
s
s
b
r
r
s
i
n
n
i
i
i
e
e
e
r
e
e
b
g
g
e
r
s
s
l
a
l
e
h
n
c
e
e
e
w
d
d
d
e
n
l
h
g
e
a
a
i
e
n
d
e
e
d
x
x
d
e
e
e
e
e
v
e
s
s
i
c
u
u
x
u
s
s
o
r
c
c
c
l
l
l
a
a
a
f f f
flexible and elastic tissues called cartilage which covers
s
l
l
l
s
e
s
s
l
l
e
l
i
i
i
t
t
b
b
c
b
c
c
c
t
a
l
l
a
a
a
s
l
t
i
s
l
s
i
i
i
t
t
a
t
r
i
i
s
s
j
j
the ends of the bones where they meet to form a joint.
i
i
t t t h e e n d s o f t h e b o n e s w h e r e t h e y me e t t o f o r m a j o i n t .
n
n
s
s
o
a
a
n
n
d
e
d
h
h
e
.
.
e
o
e
t
t
h
t
t
y
h
y
e
e
o
h
r
h
e
e
e
o
e
b
me
n
e
n
e
e
s
me
s
e
o
w
t
b
t
w
o
o
o
e
e
m
m
f
r
t
t
o
o
r
f
h
t
t
r
h
f
f
n
e
a
o
mo
o
o
e
mo
mo
r
e
r
e
h
e
e
t
t
t
T
h
t
r
r
r
a
d
u
u
a
u
• •The tip of our nose and the outermost part of our ear are
r
u
r
r
p
u
r
a
n
p
p
a
a
i
f
o
o
o
f
t
t
t
o
t
t
t
t
o
s
s
e
s
s
e
p
r
a
a
a
c
c
soft due to presence of cartilage.
s
n
f
c
o
l
l
e
c
l
i
i
i
t
o
p
t
r
g
o
f
r
a
a
a
e
.
e
g
t
t
t
e
e
e
e
r
r
g
u
s
d