This is a comprehensive powerpoit presentation on the parts and functions of digestive system.Human digestive system, system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract, or the series of structures and organs through which food and liquids pass during their processing into forms that can be absorbed into the bloodstream. The system also consists of the structures through which wastes pass in the process of elimination and of organs that contribute juices necessary for the digestive process. In order to function properly, the human body requires nutrients. Some such nutrients serve as raw materials for the synthesis of cellular materials, while others help regulate chemical reactions or, upon oxidation, yield energy. Many nutrients, however, are in a form that is unsuitable for immediate use by the body; to be useful, they must undergo physical and chemical changes, which are facilitated by digestion.

1. HUMAN
DIGESTIVE
SYSTEM

2. Digestive System
• It is also called;
• ALIMENTARY CANAL
• Commonly known as;
• GASTROINTESTINAL
TRACT (GI)

3. Digestion refers to the breakdown of food into
smaller components that can be absorbed into the
bloodstream. This digestion or catabolism is divided
into two types – the mechanical digestion of food
that occurs in the mouth when it is physically
broken up into smaller pieces and the chemical
digestion that occurs in the gastrointestinal tract
when the food is broken down into small molecules
by digestive enzymes.

4. Why is digestion important?
Digestion is important because your body needs nutrients
from food and drink to work properly and stay healthy. Proteins,
fats, carbohydrates, vitamins, minerals and water are nutrients.
Your digestive system breaks nutrients into parts small enough for
your body to absorb and use for energy, growth, and cell repair.
● Proteins break into amino acids
● Fats break into fatty acids and glycerol
● Carbohydrates break into simple sugars

5. In human beings, food needs to be processed and absorbed to obtain nutrients. This
process consists of the following five steps:
1. Ingestion - intake of food.
2. Digestion - breaking down of food so that it can be absorbed by the
body.
3. Absorption - the process of absorbing food in the form of
nutrients into the bloodstream of the body.
4. Assimilation - the process of nutrients being absorbed by each
cell of the body in the form of energy.
5. Egestion/Excretion - secretion of waste, unwanted and excess
substances from the body.

6. Functions
• Take in food( Ingestion)
• Break down the food( Digestion)
• Absorb digested molecules (Absorption)
• Provide nutrients (Assimilation)
• Eliminate waste( Egestion)

7. DIGESTION
• The breakdown of carbohydrates, lipids, proteins, and
other large molecules to their components parts.

8. INTRODUCTIONABOUT THEHUMANDIGESTIVESYSTEM
THE ALIMENTARY CANAL
1. Mouth
• the first chamber of the digestive system (First site
of Mechanical Digestion).
• Also known as Oral/Buccal Cavity.
• Food enters the body through the mouth. The mouth is
bordered by upper and lower lips and teeth with a tongue
inside.

9. I. ORAL CAVITY or BUCCAL CAVITY
1. TONGUE
• -moves food in the mouth
• -major sensory organ for taste, as well as being one of the
major organ in speech
• -its surface is normally moist, pink and covered by rough
elevation called PAPILLAE

10. • The process of digestion starts in the mouth itself. As food is crushed and
broken down, salivary glands secrete enzymes that help soften the food
and make it into a paste.

11. • .Saliva contains a digestive enzyme called amylase that is used in the digestion
process to convert starch into glucose.

12. • The saliva moistens and lubricates the mouth
cavity and the tongue. The presence of saliva
helps to make speaking and swallowing easy. It
acts as a solvent, dissolving some part of the
food to stimulate taste. It also cleans the mouth
and destroys germs.

13. • ACCESSORY ORGANS OF DIGESTIVE
SYSTEM
Teeth help with tearing, chewing, and breaking
down food particles. They also help with clarity of
speech. Humans have 32 teeth and they are the
hardest substances in the human body.

14. • ACCESSORY ORGANS OF DIGESTIVE
SYSTEM
•
TONGUE is a fleshy muscular organ in the mouth. It is
attached at the back to the floor of the buccal cavity. The
tongue helps with Manipulating food while chewing and
forms into a mass called bolus; Helps in tasting food; Helps
in mixing the watery secretion with the food; Helps in
cleaning the teeth; Helps in speaking.

15. I. ORAL CAVITY or BUCCAL CAVITY
3. SALIVARY GLANDS
-Glands that lie external to the mouth and pour their
secretory product (saliva) into ducts that empty into
the oral cavity:

16. • The salivary glands present on the tongue and produce saliva. Saliva moistens
the mouth and helps with speech and swallowing food. Saliva contains a
digestive enzyme called amylase that is used in the digestion process to
convert starch into glucose.
• The saliva moistens and lubricates the mouth cavity and the tongue. The
presence of saliva helps to make speaking and swallowing easy. It acts as a
solvent, dissolving some part of the food to stimulate taste. It also cleans the
mouth and destroys germs. Lastly, it initiates digestion by converting starch into a
simpler form called maltose.

17. I. ORAL CAVITY or BUCCAL CAVITY
3. SALIVARY GLANDS
THREE PAIRS:
b. SUBMANDIBULAR
-“Mixed or compound glands”, because they contain both serous and mucus-
producing elements.
-Located below the mandible.

18. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
2. ESOPHAGUS
• - A collapsible muscular tube that lies posterior to the
trachea and the heart. It serves as a dynamic passageway
for food, pushing the food toward the stomach.
• - Secretes mucus and transports into the stomach.
• During the act of swallowing, the bolus is transported by the
esophagus into the stomach via wave-like contraction called
PERISTALSIS

19. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
2. ESOPHAGUS
• - During the act of swallowing, the BOLUS is transported by
the esophagus into the stomach via wave-like
contraction(MOVEMENT) called PERISTALSIS

22. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
3. STOMACH
• -partially digest food.
• -where enzymatic digestion of protein begins.

23. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
• • When the stomach walls contract, chemical digestion takes place as food is
mixed and churned.
• • Chemical digestion continues as gastric juice or hydrochloric acid, and an
enzyme called PEPSIN (to break down protein).
• • After about 3 – 4 hours in the stomach, food is reduced to a thin, soupy liquid
called chyme.
• • CHYME – is made of acids, polypeptides, simple sugars, and undigested fats.

25. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
4. Small Intestine
• -important in the digestion and absorption of nutrients
Functions:
1. Segmentations mixed chyme with digestive juices and bring food into contact
with the mucosa for absorption; peristalsis propels chyme through the small intestine.
2. Completes the digestion of the carbohydrates, proteins, and lipids,
begin and completes the digestion of nuclear acids.

26. • is about 2.5 cm wide and 6 - 7
meters long.
• considered as the organ of
complete digestion and
absorption.
• Food stays in your small
intestine for 3 to 5 hours
• •About 90-95% of absorption
(through Villi – tiny hairlike
structure) of nutrients takes
place in the small intestine.

27. II. ALIMENTARY CANAL/DIGESTIVE
TRACT
5. Large intestine
• • Tube that is 6 cm wide and 1.5 m long
• • Also known as COLON.
• • Gets waste from small intestine
• • Waste stays for 18 hours to 2 days
• Appendix a small pouch that is located in our right abdomen where the
small intestine meets the large intestine. It plays no part in digestion.

29. 6. RECTUM
• • Is about 15 cm long.
• •Connects the colon to the
anus.
• •Serves as a warehouse or
storage for the undigested food
or feces/stool.

30. 7. ANUS
• It functions as the exit point
for fecal materials.
• DEFECATION is the process
of expulsion of feces/stool.

31. III. DIGESTIVE GLANDS
1. PANCREAS
• -made up of small cluster of glandular epithelial cells
• Lies posterior to the greater curvature of the stomach

32. III. DIGESTIVE GLANDS
1. PANCREAS
a. Exocrine portion: Pancreatic acini- secretes pancreatic
juice- a mixture of fluid and digestive enzymes.
b. Isles of Langerhans secretes insulin-metabolism of
carbohydrates

34. III. DIGESTIVE GLANDS
1. LIVER
• is the largest gland of the body. Aid digestion by
producing bile.
• Bile – is not an enzyme and it helps in breaking up
large fat particles into smaller ones through the process
called EMULSIFICATION.

35. III. DIGESTIVE GLANDS
• JAUNDICE- Disease in liver when bile’s enter the blood
stream
• CIRRHOSIS- Hardening of the liver
• HEPATITIS- Inflammation of the liver

37. 2. Gallbladder
● Storage tank for bile (a greenish-yellow liquid) that
helps your body break down and use fats
● Located under your liver.
● It releases bile through the bile duct into the
duodenum of the small intestine.

39. 3. Pancreas
• Is a yellowish organ that is about 18 cm long and 4 cm
wide.
• produces hormones responsible for controlling the level
of glucose in the blood.
• It produced pancreatic juice.

41. DISORDERS AND DISEASES OF THE HUMAN DIGSTIVE SYSTEM
1. Constipation – occurs when the peristalsis moves the stool in the colon too slowly.
2. Diarrhea – occurs when the lining of the large intestine cannot maintain the usual level of water
absorption.
3. Gallstones – crystals formed by too much cholesterol, bile salts and calcium in the gallbladder.
4. Appendicitis – inflammation of the appendix caused by hard mass of feces foreign body or
parasitic infection.
5. Peptic ulcers – are open sores in the esophagus, stomach, and small intestine.
6. Hepatitis – inflammation of the liver caused by excessive consumption of alcohol or a viral
infection.

42. III. DIGESTIVE GLANDS
• JAUNDICE- Disease in liver when bile’s enter the blood stream
• CIRRHOSIS- Hardening of the liver
• HEPATITIS- Inflammation of the liver

43. 7. Hemorrhoids (piles) – occur when rectal veins are inflamed and enlarged after straining and
eliminating hard stools.
8. Heartburn and acid reflux – due to the excessive secretion of hydrochloric acid in the
stomach.
9. Liver Cirrhosis- is the long-term damage to the liver from any cause that can lead to
permanent scarring.
10. Liver Cancer- almost always occurs after cirrhosis is present.
11. Colon or Colorectal Cancer – change in bowel habits, rectal bleeding, dark stools, blood in
the stool, weakness, fatigue and weight loss.
12. Indigestion or dyspepsia– is a condition caused by food stagnation due to overeating, eating
too fast and malfunctioning of the digestive system.
13. Flatulence– is the excessive amount of gases stored in the digestive tract.
14. Pica– is the eating disorder characterized by a persistent desire or appetite for substances
with no known nutritive value.

44. 15. Anorexia nervosa — often simply called anorexia — is an eating disorder characterized by
an abnormally low body weight, an intense fear of gaining weight and a distorted perception of
weight.
16. Bulimia nervosa- is a serious, potentially life-threatening eating disorder characterized by a
cycle of bingeing and compensatory behaviors such as self-induced vomiting designed to undo
or compensate for the effects of binge eating.

45. ACTIVITY 4: PREVENTIONS AND TREATMENTS
Using the discussion above, choose at least 3 disorders or diseases. Write the possible
preventions and treatments for these disorders or diseases. Follow the format below on your
answer sheet (18 POINTS; PT).
Disorder/Disease Type of Prevention Treatment
1.
2.
3.

46. THE HUMAN DIGESTIVE SYSTEM (10 POINTS; WW)
Read the following statement. Write TRUE if the statement is correct and FALSE if it is not.
___1. Ingestion refers to the breakdown of food into smaller components that can be absorbed
into the bloodstream.
___2. As digestion continues, the food is propelled from organ to organ through muscular
contractions called peristalsis.
___3. The anus is the external opening of the rectum, through which feces are expelled.
___4. The gallbladder produces insulin, which aids in the metabolism of sugars.
___5. When the stomach walls contract, chemical digestion takes place as food is mixed and
churned.
___6. The saliva moistens and lubricates the mouth cavity and the tongue.
___7. The process of digestion starts in the mouth itself.
___8. Liver Cirrhosis is the long-term damage to the liver from any cause that can lead to
permanent scarring.
___9. Pica is an eating disorder characterized by abnormally low body weight, an intense fear of
gaining weight, and a distorted perception of weight.
___10. Diarrhea occurs when the lining of the large intestine cannot maintain the usual level of
water absorption.

47. ACTIVITY 5: MY HEALTHFUL PRACTICES FOR MY HEALTHY LIFESTYLE
List down at least 5 healthful practices to keep your digestive system healthy (10 POINTS;
WW).
2.
3
4.
5.