HORMONES IN THE DIGESTIVE TRACT
Hormones released from endocrine
cells in the stomach, pancreas, and
intestine aid digestion by stimulating
the release of bile from the gallbladder
and enzymes from the pancreas into
C h o l e c y s t o k i n i n
R e l e a s e d b y t h e d u o d e n u m
in r e s p o n s e t o f a t s a n d a c id ,
c h o l e c y s t o k i n i n c a u s e s t h e
g a l l b l a d d e r t o s q u e e z e b i l e in t o
t h e d u o d e n u m a n d s t i m u l a t e s
t h e p r o d u c t i o n o f p a n c r e a t i c
e n z y m e s , w h i c h p a s s in t o
t h e d u o d e n u m t h r o u g h t h e
p a n c r e a t i c d u c t .
G a s t r in
S e c r e t e d m a i n l y b y c e l l s in t h e s t o m a c h in
r e s p o n s e t o e a t i n g f o o d ( e s p e c i a l l y p r o t e i n ) ,
g a s t r i n c a u s e s t h e s t o m a c h t o p r o d u c e m o r e
a c i d a n d s t i m u l a t e s c o n t r a c t i o n o f m u s c l e in
t h e w a l l o f p a r t o f t h e s t o m a c h , ile u m , a n d
c o l o n . T h is c o n t r a c t i o n p r o p e l s f o o d t h r o u g h
t h e d i g e s t i v e tra c t.
S e c r e t i n
S e c r e t e d b y t h e lin in g o f t h e
d u o d e n u m in r e s p o n s e t o a c i d
e n t e r i n g f r o m t h e s t o m a c h ,
s e c r e t i n a c t s o n t h e p a n c r e a s
t o i n c r e a s e t h e o u t p u t o f
b i c a r b o n a t e , w h ic h n e u t r a l i z e s
a c i d f r o m t h e s t o m a c h . I t a l s o
i n c r e a s e s t h e r e l e a s e o f
e n z y m e s f r o m t h e p a n c r e a s .
O e s o p h a g u s
F o o d e n t e r s
t h e s t o m a c h
D u o d e n u m
P a n c r e a s
that last for two or three days.
typhoid fever, cholera, food poisoning,
gastroenteritis. Gastroenteritis may be
caused by a variety of
and other organisms in
food or water. There are also a number
of non-infectious causes, such as
and certain irritant drugs.
The usual symptoms are appetite loss,
cramps, and diar-
rhoea. Their onset and severity depend
on the cause; symptoms may be mild,
or may be so severe that
and collapse occur.
M ild cases usually require rest and
only. For severe ill-
necessary, with fluids given by
venous infusion. Antibiotic drugs
given for some bacterial infections, but
others need no specific treatment.
The study of the
diseases and disorders that affect it.
Surgery that is performed to create a
connection between the
(the middle two thirds of
the small intestine), sometimes com-
bined with a partial
removal of the lower part of the stom-
ach). The operation, formerly carried
out to treat duodenal ulcer (see
), is now rarely performed.
A group of
released from spe-
cialized cells in the
and small intestine that control various
functions of the digestive organs.
are the best known
of these hormones (see
Hormones in the
t), but new hormones are
still being discovered.
The part of the
ing of the
These structures together
form a long tube through w hich food
passes as it is digested.
The medical term for
Examination of the
via a flexible
(a viewing instrument) insert-
ed through the mouth. The
(the first part of the small
intestine) are also inspected; for this rea-
son, the procedure is more accurately
called an oesophagogastroduodenoscopy.
The patient is often sedated throughout.
used to investigate
Attachments to the gastroscope enable a
(removal of a tissue sample for
analysis) to be carried out, as well as
treatments such as
troscope may also be used to ease the
passage of a gastric feeding tube through
the skin (see
opening in the
It is usually made to connect
the stomach to the outside of the body,
so that a feeding tube can be passed
into the stomach or small intestine.
Gastrostomy may be perform ed on
people w ho cannot eat properly due
to oesophageal cancer (see
gus, cancer of
) or w ho are unable to
chew and swallow due to a
in w hich the lack of
glucocerebrosidase leads to
accumulation of a fatty substance, glu-
cosylceramide, in the liver, spleen, bone
marrow, and, sometimes, in the brain.
The condition is treated by regular in -
jections of the missing enzyme.
An absorbent, open-weave fabric, usu-
ally made of cotton. Sterilized gauze is
often used to clean wounds, or applied
to soak up fluids from
wounds. It is not used on areas of dam-
aged tissue such as burns or ulcers,
because it may stick to the surface and
dislodge new tissue when it is removed.
Feeding of liquids through a
w hich is passed into the stomach
through the nose (see
The term “ gavage” can also refer to
(treating a patient by
feeding beyond appetite requirements).
A jelly-like suspension consisting
small, insoluble particles that are dis-
persed through a liquid. Gels are often