SPEECH
ly , d r a w i n g t h e d r u g p a r t i c l e s i n t o t h e
l u n g s .
A v a l v e
p r e v e n t s
t h e
g a s
f r o m
e s c a p i n g o u t o f t h e s p a c e r e x c e p t d u r -
i n g t h e t i m e i t i s b e i n g i n h a l e d t h r o u g h
t h e m o u t h p i e c e . S p a c e r s a r e p a r t i c u l a r l y
h e l p f u l f o r p e o p l e w h o h a v e d i f f i c u l t y
c o o r d i n a t i n g t h e i r b r e a t h i n g w i t h a c t i -
v a t i n g a n i n h a l e r .
s p a s m
A n i n v o l u n t a r y c o n t r a c t i o n o f a
m u s c le .
S p a s m s a r e n o t n e c e s s a r i l y p a i n f u l . E x -
a m p l e s o f s p a s m i n c l u d e c r a m p s ( o f t e n
a f f e c t i n g t h e c a l f m u s c l e s ) ,
h ic c u p s
( i n
w h i c h t h e d i a p h r a g m g o e s i n t o s p a s m )
a n d
tic s
( w h i c h
f r e q u e n t l y
a f f e c t
t h e
f a c i a l m u s c l e s ) .
L e s s
c o m m o n l y ,
a
s p a s m
m a y
b e
c a u s e d b y a n a b n o r m a l i t y i n t h e c e n t r a l
n e r v o u s s y s t e m ( b r a i n a n d s p i n a l c o r d )
o r
a
s y m p t o m
o f a
m u s c l e
d i s o r d e r .
S p a s m s c a u s e d b y d i s e a s e o f t h e n e r v o u s
s y s t e m
i n c l u d e
m y o c lo n u s
a n d
c h o re a .
O t h e r
d i s o r d e r s
t h a t
a r e
c h a r a c t e r i z e d
b y
s p a s m
i n c l u d e
t rig e m in a l n e u ra lg ia
( a f f e c t i n g t h e m u s c l e s o f t h e f a c e a n d
h e a d ) ,
te ta n y
( s p a s m c a u s e d b y a d r o p i n
b l o o d c a l c i u m l e v e l ) , a n d
te ta n u s
( a s e r i -
o u s b a c t e r i a l i n f e c t i o n ) .
B ro n c h o s p a s m
i s
a c o n t r a c t i o n
o f m u s c l e s i n t h e s m a l l
a i r w a y s
o f
t h e
l u n g s
t h a t
o c c u r s
i n
a s t h m a . I n
v a s o s p a s m
( w h i c h i s o n e o f
t h e
s y m p t o m s
o f
R a y n a u d ’s d is e a s e )
t h e r e i s a t i g h t e n i n g o f t h e m u s c l e s i n
t h e w a l l s o f b l o o d v e s s e l s .
s p a s m , c lo n ic
A t y p e o f s p a s m i n w h i c h t h e a f f e c t e d
m u s c l e
u n d e r g o e s
r a p i d
c o n t r a c t i o n s
a n d r e l a x a t i o n s . ( S e e a l s o
c lo n u s .)
s p a s m , fa c ia l
S e e
t ic
.
s p a s m , in fa n tile
A s e v e r e c o n d i t i o n t h a t a f f e c t s i n f a n t s a n d
i s a s s o c i a t e d w i t h d e t e r i o r a t i o n o f b r a i n
f u n c t i o n .
T h e
s p a s m s
i n v o l v e
f o r w a r d
f l e x i o n o f t h e h e a d , n e c k , a n d t r u n k a n d
e x t e n s i o n o r f l e x i o n o f t h e a r m s a n d l e g s .
s p a s m , to n ic
A p r o l o n g e d , i n v o l u n t a r y m u s c u l a r c o n -
t r a c t i o n .
( S e e a l s o
teta n y; te ta n u s; t o n ic -
c lo n ic s e iz u r e .)
s p a s t ic d ip le g ia
A l s o c a l l e d s p a s t i c p a r a p l e g i a , a c o n d i -
t i o n i n w h i c h t h e l o w e r b o d y m u s c l e s
a r e p a r a l y s e d a n d a b n o r m a l l y r i g i d .
s p a s t ic it y
I n c r e a s e d r i g i d i t y i n a g r o u p o f
m u s c le s ,
c a u s i n g
s t i f f n e s s
a n d
r e s t r i c t e d
m o v e -
m e n t . I t o c c u r s i n
P a rk in so n ’s d is e a se , m u l-
tip le s c le ro s is , c e re b ra l p a lsy ,
a n d
teta nus.
s p a s t ic p a ra ly s is
I n a b i l i t y
t o
m o v e a p a r t
o f t h e b o d y ,
a c c o m p a n i e d b y r i g i d i t y o f t h e m u s c l e s .
C a u s e s o f s p a s t i c p a r a l y s i s i n c l u d e
stro k e ,
c e re b ra l p a ls y ,
a n d
m u lt ip le s c le r o s is .
( S e e
a l s o
p a ra ly s is .)
s p e c if ic g ra v ity
T h e r a t i o o f t h e
d e n s it y
o f a s u b s t a n c e t o
t h a t
o f w a t e r . T h e
s p e c i f i c
g r a v i t y
o f
u r i n e ,
f o r
e x a m p l e ,
i n d i c a t e s w h e t h e r
t h e u r i n e h a s a l a r g e a m o u n t o f m a t e r i a l
d i s s o l v e d i n i t ( n e a r 1 .0 3 0 ) o r w h e t h e r
i t i s a l m o s t w a t e r ( n e a r 1 . 0 1 0 ) .
s p e c ific le a rn in g d is a b ilit y
D i f f i c u l t y i n o n e o r m
o r e a r e a s o f l e a r n -
i n g
i n
a
c h i l d
o f a v e r a g e
o r
a b o v e -
a v e r a g e
i n t e l l i g e n c e .
S p e c i f i c
l e a r n i n g
d i s a b i l i t i e s
i n c l u d e
d y s le x ia ,
i n
w h i c h
t h e c h i l d c a n n o t r e c o g n i z e l e t t e r s , a n d
d y s c a l c u l i a ,
i n w h i c h
t h e
c h i l d
h a s
a
p r o b l e m w i t h m a t h e m a t i c s .
s p e c im e n
A s a m p l e o f t i s s u e , f l u i d s , w a s t e p r o d -
u c t s ,
o r
a n
i n f e c t i v e
o r g a n i s m
t a k e n
f r o m t h e b o d y f o r a n a l y s i s , i d e n t i f i c a -
t i o n ,
a n d / o r
d i a g n o s i s . T h e
s p e c i m e n
m a y b e p r e p a r e d i n a p a r t i c u l a r w a y f o r
e x a m i n a t i o n u n d e r a
m ic ro s c o p e .
S P E C T
T h e
a b b r e v i a t i o n
f o r
s i n g l e
p h o t o n
e m i s s i o n c o m p u t e d t o m o g r a p h y , a t y p e
o f
ra d io n u c lid e s c a n n in g
.
s p e c t a c le s
S e e
g la s s e s .
s p e c u lu m
A
d e v i c e
f o r
h o l d i n g
o p e n
a n
o r i f i c e
( b o d y o p e n i n g )
t o e n a b l e a d o c t o r t o
p e r f o r m a n e x a m i n a t i o n . F o r e x a m p l e ,
a s p e c u l u m i s u s e d t o p e r f o r m a c e r v i c a l
s m e a r o r g y n a e c o l o g i c a l s w a b .
s p e e c h
A s y s t e m o f s o u n d s b y w h i c h h u m a n s
c o m m u n i c a t e . S p e e c h i n v o l v e s t h e m u s -
c l e s t h a t a r e u s e d i n b r e a t h i n g a n d t h e
l a r y n x
( v o i c e b o x ) , t o n g u e , p a l a t e , l i p s ,
j a w , a n d f a c e .
SPEECH PRODUCTION
T h e p r o d u c t i o n o f s p e e c h s o u n d s o r i g -
i n a t e s
i n
t w o
r e g i o n s
o f t h e
c e r e b r a l
c o r t e x ,
o n e a c h s i d e o f t h e
b ra in ,
t h a t
a r e l i n k e d t o t h e c e n t r e f o r l a n g u a g e e x -
p r e s s i o n ( B r o c a ’s a r e a ) i n t h e d o m i n a n t
SPEECH DEVELOPMENT IN CHILDHOOD
3 months
Period of babbling begins. The child produces strings of sounds for pleasure.
Babbling is important in building sequences of muscle movements thatwill be
used later to produce meaningful speech sounds.
9 months
The child echoes the speech of others, but words are not yet used with
meaning. By listening to and copying adults, the child learns that clusters of
sounds refer to specific objects, people, or situations.
12 to 18
months
The child beings to utter simple wordswith meaning, often accompanied by
gestures. Examples include “bye-bye”, “dog”, “hot”, and “daddy”. Single
words are used, with vocabulary gradually increasing from two or three
words initially.
18 to 24
months
The child begins to combine concepts to form two-word sentences (e.g. “Hello
John” or “That hot!”). By the age of two years, the child may be using 100 or
more different words.
2 to 3 years
The child’s sentences become longer (e.g. “I like cake” or “Peter hit Mary”). He
or she also begins to incorporate adjectives and adverbs into sentences (e.g.
“That’s daddy’s old coat” or “I want lunch now”). By the age of three years, the
average sentence length is four words. Most sounds have developed, with the
possible exceptions of “the”, “r”, “j”, “ch”, and “sh”.
3 years and
older
More elaborate sentences with several nouns, verbs in past and future tenses,
and linked phrases begin to be used (e.g. “We went to Amy’s and we had milk
and biscuits” or “I think mummy went downstairs”). However, mistakes are
often made (e.g. “What did you played?”), reflecting the child’s linguistic
immaturity. Language skills continue to develop throughout childhood.
S
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