Transcript The Digestive System

The Digestive System
3 functions
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Digestion – breakdown of food into
nutrients that can be absorbed in the
form of molecules
Absorption – passage of nutrients into
the bloodstream to be carried to body
tissues & cells
Excretion – elimination of waste
products
Gastrointestinal Tract
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Extends from mouth to anus
The gastrointestinal tract consists of the following :
Mouth
Throat
Oesophagus
Stomach
Duodenum
Small bowel
Colon
Rectum
Anus
Other organs of GIT
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Liver (hepatobiliary system)
Gallbladder
Pancreas
These organs lie outside GIT but
contribute to the Digestion process
STOMACH
LIVER
LARGE
INTESTINE
DIGESTIVE SYSTEM
Mouth
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Food is moistened and chewed (i.e.
mastication)
Contains teeth, tongue,
Contains hard & soft palate (roof of
mouth)
Contains uvula which stops food
entering the nasal cavity with
swallowing
Mouth Cont’d
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Salivary glands supply saliva with
digestive enzymes for food breakdown
Tonsils – located in oropharynx &
produce leucocytes
Oesophagus
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Is a tube connecting pharynx to
stomach
Moves food into stomach by
peristalsis
Oesophagus word component
Word Root Combining
form
Oesophag oesophag/o
Meaning
oesophagus
Stomach
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Hollow organ
Lies below diaphragm in upper abdominal
cavity, LUQ
It is divided into three (3) sections
i) the fundus
ii) the body which is the middle
section
iii) the pylorus (the lower, small end).
Stomach cont’d
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Gastric juices break down the food into watery
material to make absorption easier
Pepsin (an enzyme) also breaks down food
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Has 2 sphincters
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1. cardiac sphincter – prevents
regurgitation into oesophagus
2. pyloric sphincter – controls passage
of food into small intestine
Word Components
Word Root Combining
form
Meaning
gastr
gastr/o
stomach
pylor
pylor/o
pylorus
Small Intestine
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Is 6 metres long
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Nutrients from broken down food is absorbed
through the intestinal walls
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3 sections
1. duodenum –connected to pylorus of
stomach
2. jejunum – middle section
3. ileum- lower section and joins onto large
intestine
Stoma -stomy
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Stoma means a surgical opening
-stomy is also referred to an operation to
form an opening between two parts e.g.
stomach to abdomen
Can be an opening from the intestine onto
the outside of the body after surgical removal
of part of intestine
-stomy
Is joined onto combining forms to add
meaning e.g.
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Jejun / o / stomy
is creation of a new opening through the
abdominal wall into the jejunum
Ile /o / stomy
is creation of a new opening through the
abdominal wall into the ileum
-stomy
It is also used with two combining forms for
organs & means an opening between two
body parts or organs that would normally be
separated
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Gastr / o / enter / o /stomy is a new surgical
opening between stomach and small intestine
NB: when the 2 combining forms gastr/o and enter/o
are joined the combining vowel is retained
Suffixes
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Gram – refers to a drawing or picture
Graphy – refers to the technique of
making a recording
Graph – refers to the instrument that
make the recording
Word components
Word root
gastr
Combining
form
gastr/o
duoden
duoden/o
jejun
jenun/o
ile
ileo /o
Meaning
stomach
Large Intestine (i.e. large
bowel)
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1 metre long
Water is absorbed through large
intestine back into body
waste becomes solid
Large Intestine cont’d
3 major sections
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Caecum hold appendix
Colon – ascending colon
transverse colon
descending colon
sigmoid colon
rectum
Word components
Word Root
Combining
Form
Meaning
caec
caec/o
a blind ended pouch
appendic
appendic/o
appendage
col
col/o
large bowel
sigm
sigmoid/o
sigmoid colon
rect
rect/o
rectum
peritone
peritone/o
peritoneum, membrane covering
abdominal organs
Liver
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Liver –manufactures & releases bile
Lies in RUQ
Word Root
Meaning
Hepat
Combining
Form
hepat/o
Chol
chol/e
bile
liver
Gallbladder
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Lies inferior surface of liver
stores bile & releases bile through common
bile duct into duodenum
Word Root
Combining Form
Meaning
cyst
cyst/o
bladder,combined with chole it
refers to gallbladder
choledoch
choledoch/o
common bile duct
lapar
lapar/o
soft part between ribs & hips
refers to the abdomen
Pancreas
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Lies posterior to stomach
Produces juices filled with enzymes to digest
food
Releases digestive juices into the duodenum
Secretes insulin which is a hormone is
released when blood sugar levels rise
pg 42
Procedures
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Cholecystectomy
Cholecystography
Colonoscopy
Enterectomy
Hemicolectomy
Laparoscopy
Uvulopalatopharyngoplasty
pg 44
Prefixes
Prefix
Meaning
dys
difficult
dyspepsia
difficulty with digestion
hypo
below
hypoglossal
below the tongue
sublingual
below the tongue
hyper
above.or more than normal
hyperemesis
excessive vomiting
Suffixes
Suffix
Meaning
pepsia
digestion
ostomy
surgical opening
colostomy
surgical opening into colon
otomy
surgical incision
gastrotomy
surgical incision into the
stomach
pg 45
Diseases and disorders
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Adhesion – fibrous band
Ascites – accumulation of fluid in abdominal
cavity
Cachexia – abnormally low weight
Cirrhosis – scarring of an organ (liver)
Divrticulum – abnormal pouch in wall of a
tube (colon )
Cholelithiasis – stones in gallbladder pg 46