The document discusses the digestive system of mammals and birds. It describes the main parts of the digestive tract including the mouth, esophagus, stomach, small intestine, large intestine, and anus. It explains the key functions of each part, such as mechanical and chemical breakdown of food, absorption of nutrients, and excretion of waste. Accessory organs like the liver and pancreas secrete bile and enzymes to further break down food into absorbable molecules.

1. ERIES D.
ISIDERIO
Capiz State
University-LHS
Roxas City, Capiz,
Philippines

2. DIGESTIVE
SYSTEM
(MAMMAL AND
BIRDS)

3. WHAT IS
DIGESTIVE
SYSTEM?

4.  In order to survive, animals must
feed by ingesting solid or liquid food
matter obtained from other
organisms, such as plants or other
animals.
 Digestive System - The organs
and glands in the body that
are responsible for digestion.

5.  The intake of food from these
sources (plants or other animals) and
the processes that convert food
substances into living matter are
known as nutrition.
 Specifically, this mode of feeding
found in animals is known as
holozoic nutrition.

6. It involves the taking
in of food.
INGESTION/
FEEDING

7.  The process of mechanical and
chemical breakdown whereby
large food molecules are broken
down into soluble and diffusible
molecules that can be absorbed by
the body cells.
DIGESTION

8. Breakdown of food by
chewing and the action of
muscles (churning) within
the stomach.
MECHANICAL
digestion

9.  Breakdown of food by enzymes
produced at various stages of
the digestive tract
CHEMICAL
digestion

10.  Is a digestive enzyme that
helps the body break down
carbohydrates.
 Both the salivary glands and
the pancreas produce amylase.
 To experience amylase in
action, chew on a cracker for a
minute and you will find that it
starts to taste sweet.
AMYLASE

11.  Is an enzyme that break
down proteins, which are
found throughout the
body, including trace
amounts in the saliva.
 Changes in kallikrein
enzymes have also been
linked to certain cancers.
KALLIKREIN

12.  Is an enzyme that breaks
down fatty acids.
 Lingual lipase is very
important for infants
because it helps them digest
the fats in milk, making
digestion much easier for
their immature systems.
LIPASE

13. the process whereby
digested food materials are
taken into the body cells.
ABSORPTION

14. The conversion of absorbed
food into the substance of
the body.
ASSIMILATION

15. The elimination of food
waste materials from
the body.
EGESTION

16. THE HUMAN
DIGESTIVE
TRACT

17.  The human digestive tract is a
long, coiled, muscular tube that
stretches from the mouth to the
anus.
 From mouth to the anus, the
human food tube or the
digestive tract is about nine
meters long.
The Human
digestive tract
9 meters

18. How Digestion
is done?

19.  Food processing begins in the mouth.
 The bite food is then swallowed and is moved
through the pharynx into the esophagus.
 Then, food is mechanically and enzymatically
digested in the stomach.
 Most enzymatic digestion takes place in the
small intestine
 The large intestine then eliminates wastes
leading to the opening for the elimination of
wastes called anus.

20. SPECIALIZED REGIONS WHERE DIGESTION TAKES PLACE
MOUTH
PHARYNX
ESOPHAGUS
STOMACH
SMALL INTESTINE
LARGE INTESTINE
ANUS

21.  The intake of food starts
from the mouth, which
leads into the mouth cavity.
 Around the sides and front
of the cavity are the upper
and lower jaws. The upper
jaw is fixed, while the
lower is movable.
MOUTH

22.  Mechanical digestion starts in
the mouth (mastication)
where four kinds of teeth tear
the food into pieces: Incisors
– thin-edged for cutting food;
Canines – are pointed used
for tearing; Molars &
Premolars – specialized for
crushing and grinding.
MOUTH

23.  There are three pairs of
salivary glands (parotid,
submandibular and sublingual)
that open into the mouth cavity
via ducts that release a
secretion called saliva.
 The mucin in saliva helps to
soften the food, while chewing
helps to break down the food
into smaller pieces.
MOUTH

24.  The pharynx is a
common passage of
both air and food.
 It is the part of the
gut between mouth
and esophagus.
PHARYNX

25. PHARYNX

26.  After swallowing, smooth
muscles force the food into
a narrow, muscular tube
called the esophagus or
gullet.
 The word esophagus
comes from a Greek word
meaning “to carry what
is eaten”.
ESOPHAGUS

27.  Muscle layers that surround
the esophagus consist of an
outer layer of longitudinal
and an inner layer of circular
smooth muscle.
 These two layers of smooth
muscle cause rhythmic,
wavelike contraction and
relaxation – such movement
is called peristalsis.
ESOPHAGUS

28.  Peristaltic action – allow us
to digest food even upside
down and help astronauts in
space to have a normal
digestion while floating in
space.
 It takes about seven
seconds for each bolus to
make the journey
ESOPHAGUS

29.  The partially digested
food now enters a J-
shaped organ called
stomach, which lies
beneath the diaphragm
and partly covered by
the liver.
STOMACH

30.  When empty, the stomach is collapsed and
shaped almost like a hot dog. Once food
enters, the folds of stomach wall called
rugae smooths out and expands to more
than a liter.
 The stomach lining bears numerous pits
lined with gastric glands which release
strong gastric juices. Such gland was
stimulated by the foods in the stomach.
STOMACH

31.  While food is in the stomach, it
undergoes both mechanical
and chemical digestion.
Peristalsis in the stomach wall
churns the food and mixes it
well with the gastric juice.
These actions attack the food
in a chemical way breaking
down and dissolving its
nutrients.
STOMACH

32.  Gastric juice is a solution of hydrochloric
acid and the pepsin. It provides a slightly
acidic medium suitable for the action of the
gastric enzyme, such as pepsin breaks some
of the complex proteins and also kills germs
and certain potential parasites.
 Food found in the stomach is called chyme.
 The food normally remains in the
stomach for about three to six hours.
STOMACH

33.  Digestion is completed in the small
intestine and nutrients are
absorbed through its wall (villi).
 The small intestine is about 5 to 6
meters (about 17ft.) in length and
has three regions: duodenum,
jejunum and ileum
SMALL INTESTINE

34. SMALL INTESTINE

35.  The majority of chemical digestion
occurs in the first of three sections of
the small intestine known as the
duodenum.
 This section also contains an opening
from the bile duct and pancreatic duct
through which bile and pancreatic
enzymes enter the small intestine.
SMALL INTESTINE

36.  Undigested food passes through
the large intestine. Although
shorter in length than small
intestine, it is called large because
of its diameter.
 The large intestine is 1.3m (about
4ft.) in length.
LARGE INTESTINE

38.  The main function of the large
intestine is to absorb water and
minerals salts from the undigested
food material.
 After about 18 or 24 hours in the large
intestine, most of the water that is
contained in undigested food is
absorbed.
LARGE INTESTINE

39.  Materials that are not absorbed in the large
intestine form a solid waste known as
feces.
 Feces, which is made up of dead bacteria
and some fat protein is temporarily stored in
the rectum.
 When the rectum contracts, the feces is
expelled through an opening called anus.
LARGE INTESTINE

40. Associated
Organs in
Digestion

41.  The liver is a large accessory organ of
the digestive system that is constantly
producing a fluid known as bile.
 Bile contains bile salts that emulsifies
fats which means it breaks them into
smaller droplets so they can be
digested. Bile is temporarily stored in
the gallbladder.
LIVER

42. LIVER

43.  Is a soft triangular
gland lying between
the small intestine and
the stomach. The
pancreas produces
pancreatic juice, which
is a mixture of digestive
enzymes.
PANCREAS

44.  These enzymes move into the small
intestine at the same time the bile does and
help to break down proteins, starches and
fats.
 The pancreas also secrets the hormone
insulin, which plays an important role in the
control of the blood sugar level in the body
and utilization of carbohydrates.
PANCREAS