Digestive System PPT.pdf................

Nursing collage

1. Prepared by :
Rdwan Basheer
Miyasar Alyas
Warven Hamid
Zhyan Ghazi
Ibtsaam Asmaeel
Digestive system anatomy and
physiology
Duhok Polytechnic University
Technical College Of Health / Shekhan
Department Of Nursing / 1
st
Stage
Subject : Anatomy
Supervised by:
Dr. Abdullah Muzahim
[2023-2024]

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Function of digestive system

1. Ingestion: taking food into mouth.
2. Secretion: release of water, acid,
buffers, and enzymes into lumen
of GI tract.
3. Mixing and propulsion: churning
and movement of food through GI
tract.
4. Digestion: mechanical and
chemical breakdown of food.
5. Absorption: passage of digested
products from GI tract into blood
and lymph.
6. Defecation: elimination of feces
from GI tract.

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The organs of digestive system

❖ Gastrointestinal (GI) tract, is a continuous tube
that extends from the mouth to the anus through
the thoracic and abdominopelvic cavities . organs
include…
1. mouth,
2. pharynx,
3. esophagus,
4. stomach,
5. small intestine,
6. and large intestine
❖ Accessory digestive organs that participate in
directly in digesting of food.
organs include…
1. teeth,
2. tongue,
3. salivary glands,
4. liver,
5. gallbladder,
6. and pancreas

5. Mouth
•Teeth mechanically
break down food into
small pieces. Tongue
mixes food with
saliva (contains
amylase, which helps
break down starch).
•Epiglottis is a flap-like
structure at the back of
the throat that closes
over the trachea
preventing food from
entering it. It is located
in the Pharynx.

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• function of pharynx : Delivers food and
liquid to your esophagus, which sends
them on to your stomach
•Shape of pharynx : is a ring-like muscular
tube
•Structure of pharynx : the pharynx divides
into three parts which are from superior
to inferior:-the nasal pharynx, located
behind the posterior nasal apertures
(choanae), the oral pharynx, located
behind the opening of the oral cavity, and
the laryngeal pharynx, located behind the
inlet (opening) of the larynx.
•Location of pharynx :is a muscular tube in
the middle of your neck
pharynx

7. Esophagus
•Approximately 20 cm
long.
•Functions include:
1.Secrete mucus
2.Moves food from the
throat to the stomach
using muscle movement
called peristalsis
•If acid from the
stomach gets in here
that’s heartburn.

8. Stomach
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•J-shaped muscular bag that
stores the food you eat, breaks it
down into tiny pieces.
•Mixes food with Digestive Juices
that contain enzymes to break
down Proteins and Lipids.
•Acid (HCl) in the stomach Kills
Bacteria.
•Food found in the stomach is
called Chyme.

9. Small Intestine
•Small intestines are roughly 7 meters
long
•Lining of intestine walls has finger-like
projections called villi, to increase
surface area.
•The villi are covered in microvilli which
further increases surface area for
absorption.

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10. Small Intestine
•Nutrients from the food pass into the
bloodstream through the small
intestine walls.

•Absorbs:
–80% ingested water
–Vitamins
–Minerals
–Carbohydrates
–Proteins
–Lipids

•Secretes digestive enzymes


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11. Large Intestine
•About 1.5 meters long
•Accepts what small intestines don’t
absorb
•Rectum (short term storage which
holds feces before it is expelled).

12. Large Intestine
•Functions
–Bacterial digestion
•Ferment
carbohydrates
– Absorbs more water
– Concentrate wastes

13. Accessory Organs The Glands
•Not part of the path
of food, but play a
critical role.
•Include: Liver, gall
bladder, and
pancreas

14. Liver
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The liver’s primary contribution to
digestion is the production of bile or
gall which drains into the
duodenum, and some is stored in
the gallbladder. It travels through the
hepatic ducts, which merge together.
Bile helps digest fats. The liver also
stores iron and the fat-soluble
vitamins A, D, E, and K.
filters out toxins and waste including
drugs and alcohol and poisons.

15. Gall Bladder
•Stores bile from the liver, releases it
into the small intestine.
•Fatty diets can cause gallstones
•Bile stored in the gallbladder becomes
more concentrated, increasing its
potency and intensifying its effect.
When chyme containing fat leaves the
stomach, the gallbladder contracts and
discharges bile through the cystic duct
and common bile duct and into the
duodenum of the small intestine.

16. Pancreas
•Produces digestive
enzymes to digest fats,
carbohydrates and
proteins
•Regulates blood sugar
by producing insulin

17. The rectum is where feces are
stored until they leave the
digestive system, through the
anus as a bowel movement.
As the rectal walls expand with
waste material, receptors from
the nervous system stimulate the
desire to defecate. For defecation
or egestion, we consciously relax
the external anal sphincter
muscle to expel the waste
through the anus.

The rectum and anus…

18. References and Links
•Your Digestive System and How It Works
–Digestive system diagram comes from this site
•The Real Deal on the Digestive System
•Pancreas: Introduction and Index
•Your Gross and Cool Body - Digestive System
•Laurentian Regional High School Data Base
- you must know the Username and Password