Download The Liver

班级：09级五班二组
组长：杨磊
演讲：朱兴兴
时间：2011/11/15
The digestive system
Introduction
digestive
tract (gastrointestinal tract,
GI tract) (mouth, pharynx, esophagus,
stomach, small intestines, and large
intestines) and accessory organs (liver,
pancreas, gall bladder, teeth, salivary
glands).
Functions of the Digestive System:

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Digestion – chemical break down of food by
enzymatic, hydrolysis, or acids
Ingestion – insert in mouth by conscious
choice
Absorption – movement across digestive
epithelium to interstitial fluids
Excretion – removal of wastes and indigestible
residue
The Oral Cavity
(Buccal cavity): bound by
the cheeks and lips (labia),
the mouth opens into
oral cavity, start of the
digestive tract

The Teeth

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Deciduous teeth (20 baby teeth)
Secondary dentition or permanent teeth (32
adult teeth):
Types
 Incisors – blade shaped teeth at the front of the
mouth (8). Single root
 Cuspids – (canines) conical with a pointed tip (4).
Single root
 Bicuspids – (premolars) flattened crowns that
crush/grind (8). Single or double root
 Molars – large flattened crowns that excel at
crush/grind (12). 3 or more roots
The Tongue
The tongue exends across
the floor of the oral cavity
and is attached by muscles
to the lower jaw bone .
papillae can sense
flavors ,such as
sweet ,bitter, salty, and sour.
Palate


Forms the roof of the
mouth.
Divided into two parts: the
hard palate and the soft
palate
The Pharynx

muscles of the pharynx contract and push bolus
down to the esophagus. Peristaltic waves push the
bolus down the esophagus to the stomach
The Esophagus

(or throat) is a long muscular
tube that serves as a
passageway for food from the
mouth to the esophagus and
as a passageway for air from
nose to the windpipe.
The Stomach

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A pouch-like located in the upper part of the
abdominal cavity ,connects the esophagus with
the small intestine.
When the stomach is empty, the mucous
membranes lining its walls are highly folded;
As the stomach fills, the rugae unfolded
Fundus of stomach
Cardia
Body of stomach
Pyloric canal
Pyloric antrum
Pyloric part
The Small Intestine
(small bowel) is the region
of the gut where nearly all
of the chemical digestion of duodenum
the nutritional components
of food takes place.
jejunum
 Divided into three sections:
the duodenum, the jejunum,
the ileum.

ileum
The Large Intestines

Compared with the small intestine, the larger
intestine is relatively inactive and has mach less
functions.
The Cecum

A pouch on the right side,
is connected to the small
intestine by the ileocecal
valve, which controls the
passage of fluid waste from
the small intestine into the
large intestine.
The Colon

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Which comprised the
main length of the
large intestine.
Has three divisions:
the ascending, the
transverse, and the
descending.
The sigmoid colon,
shaped like an S.
The Rectum
Serves as a reservoir for feces.
Accessory Digestive organs
The liver
The gallbladder
The pancreas
The Liver
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A large glandular organ
located in the upper right
quadrant of abdomen,
produces a greenish fluid
called bile.
Other functions:
manufactures blood
proteins, removes
poisons, sores and
releases glycogen.
The Gallbladder

A pear-shaped sac behind
the lower portion of the
liver, stores bile, which is
continuously secreted by
the hepatic cells between
meals.
The Gancreas

An elongated organ just
behind the stomach,
manufactures digestive
juice containing
enzymes (amylase and
lipase ) that aid in the
digestion of proteins,
starches and fats.
Listening and watching

The digestive system
Can you speak them？
the oral cavity
Pharynx
Esophagus
Stomach
Liver
Duodenum
Ileum
Pancreas
Large
intestine
Jejunum