The document provides an overview of the major organs of the human body, describing their structure and functions, including the brain, heart, lungs, liver, stomach, intestines, kidneys, bones, and muscles. It explains how these organs work collectively within systems (e.g., nervous, circulatory, respiratory, digestive) to maintain homeostasis and ensure survival. Key processes such as blood circulation, gas exchange, digestion, and waste removal are also highlighted, illustrating the essential roles of each organ.

3. MAJOR ORGANS OF THE BODY
What makes up your body?
• Cell - is the basic unit of living matter.
- made up of approximately 100 trillion – 100000000000000 cells).
- Cells are responsible for digestion of food, excretion of wastes and transportation of blood.
• Tissue – the group of cells that work together.
• Organ is formed when tissues worked collectively.
• Organ system is formed by the organs.
• Organisms are different organ system that make up together.
• Homeostasis means balance or equilibrium. The major organs of the body perform several functions to keep you
alive and healthy.

4. MAJOR ORGANS OF THE BODY
BRAIN
• It is found inside the skull (skull is the bone structure of the head that
supports the face and protects the brain).
• It is the main organ of the nervous system.
• It is the control center of all actions of the body parts.
• Spinal cord carries nerve signals from your brain to your body and vice
versa.
• Helps the body perform voluntary and involuntary functions
including emotions, speech, memory and judgement.
• Helps in communicating sensory information such as seeing,
touching, hearing, smelling and tasting.

5. HOW DOES THE BRAIN WORKS?
midbrain
Cerebrum
(Forebrain)
Cerebral
cortex
Brainstem Cerebellum
(Hindbrain)

6. • Cerebrum ((Forebrain)
- The largest part of the brain.
- Controls sensory information and voluntary muscle contractions.
• Cerebral cortex
- outer layer of the cerebrum.
- responsible for sight, movement, sensation and language.

7. • Cerebellum (Hindbrain)
- integrates the sensory signals from the ears, eyes and muscles to help the
body maintain balance and coordination of movements.
• Medulla oblongata (brainstem)
- controls reflex activities such as heartbeat and breathing.
• Hypothalamus
- responsible for homeostasis.
- It contains the centers for controlling and integrating metabolism and
appetite, body temperature, water balance and sleep.
• Thalamus
- receives impulses from different sensory areas and passes them to the
cerebrum.

8. MAJOR ORGANS OF THE BODY
HEART

9. MAJOR ORGANS OF THE BODY
HEART
• It is an organ of the circulatory system.
• Its main function is to pump blood throughout the body, supplying oxygen
and nutrients to the tissues and removing carbon dioxide and other wastes
from the cells.
• It is an involuntary cardiac muscle located at the chest and as big as your fist.
• It has four chambers or hollow spaces : upper chambers called atriums and
lower chambers called ventricles.
• ATRIUMS are referred as holding chambers, that receives oxygen-poor
blood from the body.
• VENTRICLES referred as the pumping chambers, pump oxygen-rich blood
from the lungs to the body.

10. • Blood vessels delivers blood to the organs and tissues in your
body.
TYPES OF BLOOD VESSELS
• Arteries- carry blood away from the heart.
• Veins – carry blood towards the heart.
• Capillaries – allow the exchanges of gases and nutrients
between blood and tissues.
• Cardiovascular system
- made up of heart, blood and blood vessels.
- responsible for circulation in the body.

11. HOW DOES THE HEART WORKS?
Blood Circulation through the Heart
https://www.youtube.com/watch?v=tg_ObDJEaGo
The deoxygenated or oxygen-
poor blood from your body
enters the right atrium of the
heart.
It is then pumped to the lungs
through the right ventricle.
The lungs remove impurities
and carbon dioxide and
produce oxygenated or
oxygen rich blood.
From the lungs, the
oxygenated blood enters the
heart through the left atrium.
It is then pumped to the body
through the left ventricle.
Finally, the oxygen-rich blood
is dispersed to all the body
organs through the capillaries
to keep tissues and cell alive.

12. MAJOR ORGANS OF THE BODY
LUNGS
• It is made up of elastic, sponge tissue.
• A part of the respiratory system that work together with the cardiovascular
system in the delivery of oxygen and nutrients to the different parts of the
body.
• It is where gas exchange occurs.
• Oxygen is taken from the outside environment and
• carbon dioxide is eliminated as the waste product
• of respiration in the body.

13. • Bronchiolar muscle - induces airway
narrowing.
• Alveoli - tiny air sacs at the end of the
bronchioles.
• Bronchi - the large air passages that lead
from the trachea (windpipe) to the lungs.
• Bronchioles - are air passages inside the
lungs that branch off like tree limbs from
the bronchi.

14. HOW DOES THE LUNGS WORKS?
GAS EXCHANGE INSIDE THE LUNGS
As you breathe in or
inhale , your nose or
mouth collects and
filters the air from the
outside environment.
The trachea or
windpipe brings
the oxygen to
your lungs.
Inside the lungs,
oxygen is transferred
to the blood in the
heart through the
alveoli or any tiny air
sacs.
As you breathe out or
exhale, the carbon dioxide
and other impurities from
tissues and cells are
removed through alveoli.

15. MAJOR ORGANS OF THE BODY
LIVER
• It is the largest internal organ and is part of the digestive system.
• It is a gland that produces bile, which aids digestion and breaks down fats in
the food we eat.
• It is responsible for taking the toxins out of the blood.
*The body cannot survive without a healthy liver.

16. HOW DOES THE LIVER WORKS?
FUNCTIONS OF THE LIVER
Produces a liquid
knowns as bile, which
aids in digestion and
breaks down fats in
the food we eat.
Its network of
veins warms the
blood and helps
maintain body
temperature
Eliminates ammonia
that comes from
amino acids when
making blood sugar
Filters out toxic
wastes in your
blood and have
them disposed of
in the urine.

17. MAJOR ORGANS OF THE BODY
Stomach and Intestines
pharynx
esophagus
large intestine
small intestine
liver
anus
stomach
rectum

18. Stomach and Intestines
• Stomach and intestine are organs of the digestive system.
• Stomach
• is a flexible hollow muscular organ shaped like a bag that can expand.
• it can contain up to 3 liters of food for two to five hours each meal.
• It secretes enzyme to help in digestion of food – pepsin for protein digestion and hydrochloric
acid for maintaining the acidic environment within the stomach to eliminate pathogens that may
enter the body along with food
• Small intestine
• It is the most vital part of the food tube or alimentary canal.
• It contains digestive juices and other enzymes that helps in the final digestion of food.
• Villi is the inner walls of the small intestine that is consist of finger-like projections. It
brings blood closer to the digested food for the absorption of nutrients.

19. • Large intestine
• Also known as “colon”
• It absorbs water from the undigested food and recycle the water back to the body.
• Feces are the undigested food when water is absorbed.
• Pharynx
• usually called the throat.
• It carries air, food and fluid down from the nose and mouth.
• Esophagus
• the muscular tube that carries food and liquids from your mouth to the stomach.
• Rectum
• the concluding part of the large intestine that terminates in the anus.
• Anus
• the opening of the rectum through which stool passes out of your body.

20. HOW DOES THE STOMACH AND LARGE INTESTINE WORKS?
After the food mass or bolus is
ground between teeth and
mixed with saliva, it passes to
the esophagus, which links the
mouth to the stomach
Then, the small intestines
absorbs nutrients and
distributes them throughout
your body by the circulation
of blood.
The stomach twists, squeezes,
churns and mixes food with gastric
juices. Then, the chyme (food +
enzymes + gastric juices) squirts
into the small intestines.
The esophagus moves in
wavelike motion, called
peristalsis , to push the bolus
down the stomach
The undigested food cannot pass through the villi
so it enters the large intestine. The walls of the
large intestine absorb excess water, which is taken
back to the tissues. Thus undigested food waste ,
known as feces collects at the rectum and is
eliminated through the anus.

21. MAJOR ORGANS OF THE BODY
KIDNEY
• The body is consist of two bean-shaped kidneys.
• It helps to remove the excess salt, water and waste products from the blood.
• It secretes hormone that activate the bone marrow to produce red blood cells,
which carry oxygen throughout the blood.

22. KIDNEY
• right kidney
• It is positioned slightly lower.
• Smaller in size.
• left kidney
• It is positioned slightly higher.
• Larger in size.
• renal arteries
• are large blood vessels that carry blood from your
heart to your kidneys
• renal veins
• are blood vessels that return blood to the heart
from the kidney.
• Ureter
• a tube that carries urine from the kidney to the
urinary bladder.
right
kidney
renal arteries
and renal veins
ureter
left
kidney

23. HOW DOES THE KIDNEYS WORKS?
Through the
renal
arteries,
both kidneys
receive
blood for
filtration and
removal of
wastes.
The clean
and filtered
blood returns
to your body
through the
renal vein.
From the
kidneys, all
wastes and
extra water
or urine are
carried to the
bladder
through the
tubes called
ureter.
The bladder
serves as
temporary
storage of
urine until it
passed from
the body
through the
urethra.

24. MAJOR ORGANS OF THE BODY
BONES
• Bone is a part of the skeletal system.
• a rigid tissue that constitutes part of the skeleton in most vertebrate.
• Bones protect the various organs of the body, produce red and white blood
cells, store minerals.
• It also provide structure and support for the body, and enable mobility.
• Serves as the storage of minerals like calcium and phosphorus.
• Marrow is the soft tissue of the bone. It is consists of red blood cells
( delivers oxygen and nutrients throughout the body ) and white blood cells (
protects the body against infection and diseases ).
• The skeletal system is composed of bones, tendons, ligaments and cartilages.

25. ALL about BONES
• Cartilages
• Fibrous connective tissues that cover the ends of
some bones to prevent wear and tear.
• Ligaments
• Strong cords of connective tissues that can stretch
and produce synovial fluid.
• Synovial membrane
• are connective tissue membranes that line the
cavities of the freely movable joints such as the
shoulder, elbow, and knee.
• Synovial fluid
• also known as joint fluid
• a thick liquid located between your joints.
• Joint cavity
• a joint that is filled with synovial fluid.
fibrous capsule
synovial
membrane
Joint cavity with
synovial fluid
bones
cartilages

26. MAJOR ORGANS OF THE BODY
MUSCLES
• Muscle is part of the muscular system which is consist of 650
muscles.
• It is composed of tiny nerves, blood vessels and bundles of fiber
that gives the human body its definite shape and form.
• Muscles make up nearly half of the body weight.
• The muscles of the human body works with the skeletal system.

27. MUSCLES
• Chest muscles
• Biceps
• Flexors
• Abdominal muscles
• Quadriceps
• Flexors
abdominal
muscles
biceps
chest muscles
flexors
quadriceps
flexors

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