The document provides an overview of human organs and organ systems, detailing 78 organs, including vital organs like the brain, heart, kidneys, liver, and pancreas. It explains the function of major organs, their roles in maintaining bodily functions, and how they are part of specific organ systems such as respiratory, digestive, and circulatory systems. The information is aimed at a grade 5 science level, emphasizing the complexity and interconnectivity of human biology.

1. Human Organs and Organ
Systems
Grade 5 Science

2. Organs
• An organ is a collection
of tissues that perform a
particular function (job)
in the human body.
• The tissue is connected
and constructed as a
unit to perform its
function.

3. The 78 Organs of the Human Body
1. Adrenal glands
2. Anus
3. Appendix
4. Bladder (urinary)
5. Bones
6. Bone marrow (spongy part of the bone)
7. Brain
8. Bronchi (tubes in the lungs)
9. Diaphragm (muscle of breathing)
10. Ears
11. Esophagus (food pipe)
12. Eyes
13. Fallopian tubes
14. Gallbladder
15. Genitals
16. Heart
17. Hypothalamus (in the brain)
18. Joints
19. Kidneys
20. Large intestine
21. Larynx (voice box)
22. Liver
23. Lungs
24. Lymph nodes
25. Mammary glands
26. Mesentery (covering of the intestines)

4. The 78 Organs of the Human Body
27. Mouth
28. Nasal cavity
29. Nose
30. Ovaries
31. Pancreas
32. Pineal gland
33. Parathyroid glands
34. Pharynx
35. Pituitary gland
36. Prostate
37. Rectum
38. Salivary glands
39. Skeletal muscles
40. Skin
41. Small intestine
42. Spinal cord
43. Spleen
44. Stomach
45. Teeth
46. Thymus gland
47. Thyroid
48. Trachea
49. Tongue
50. Ureters
51. Urethra
52. Uterus

5. The 78 Organs of the Human Body
53. Human skeleton
54. Ligaments (connect muscles to bones)
55. Tendons (connect bones to bones)
56. Blood cells
57. Vagina
58. Hair
59. The vestibular system of the ear
60. Placenta
61. Testes
62. Nails
63. Vas deferens
64. Seminal vesicles
65. Bulbourethral glands
66. Penis
67. Scrotum
68. Parathyroid glands
69. Thoracic ducts
70. Arteries
71. Veins
72. Capillaries
73. Lymphatic vessels
74. Tonsils (Waldeyer’s ring of tissues)
75. Nerves
76. Subcutaneous tissue
77. Olfactory epithelium (nose)
78. Cerebellum

6. The Most Vital
Organs
1. Skin
2. Brain
3. Heart
4. Kidneys
5. Liver
6. Pancreas
7. Stomach
8. Small intestine
9. Large intestine
10. Lungs

7. Skin
• The skin is the largest organ in the human body.
• Its main job is to maintain the body's temperature.
• The skin contains sweat glands and oil glands. Oil released
by the skin releases helps keep the skin from drying out and
the hair from becoming brittle.
• The skin also regularly sheds cells to maintain its
effectiveness.

8. Brain
• The brain stores information, allows you to think and learn
and controls vital daily functions (such as digestion, heart
rate and breathing).
• The brain receives impulses from nerves, which are located
throughout the body, and responds to pain and other
stimulation.
• Even though the brain is so important, it is also very
delicate. The brain is made of soft tissue and is protected
only by the skull, therefore head injuries can be serious.

9. Heart
• The heart is another vital organ. In an average lifetime, the
heart beats more than 2.5 million times.
• The heart's job is to pump oxygenated blood throughout the
body and receive deoxygenated blood in return.

10. Kidneys
• The kidneys are located under the rib cage in the lower
back.
• The kidneys filter things, such as water and salts, out of the
blood and produce urine.
• The kidneys also produce an enzyme called rennin. This
enzyme plays a big role in regulating blood pressure.

11. Liver
• The liver is in the upper abdomen, slightly to the left.
• The main job of the liver is to produce bile, which it sends to
the stomach for digestion.
• The liver also filters out toxins and regulates blood sugar.
• Blood sugar is regulated by the liver, which converts and
stores sugar and releases it as needed into the bloodstream.
• The liver is also in charge of releasing cholesterol, breaking
down fats and producing blood proteins. It is the largest
internal organ.

12. Pancreas
• The pancreas is located behind the stomach.
• The job of the pancreas is to produce enzymes necessary for
digestion and send them to the stomach.
• The pancreas also regulates blood sugar by producing
insulin.
• The pancreas also creates glucagon that has the opposite
effect of insulin and helps to maintain blood sugar levels.

13. Stomach
• The stomach receives food from the esophagus and sends it
into the small intestine.
• The stomach's role in digestion is to break down food and
mix it with digestive enzymes.

14. Small intestine
• The job of the small intestine is to digest food.
• It does this by using chemicals, such as enzymes.
• The small intestine also absorbs nutrients and transfers
them to the blood.
• The small intestine is five meters long. The food moves from
the small intestine to the large intestine with a series of
muscle contractions.

15. Large intestine
• The large intestine is located in the abdomen and is 1.5
meters in length.
• The large intestine is involved in digestion. It receives
undigested food from the small intestine.
• The large intestine absorbs as much water as possible from
the food and then expels the waste and any excess fiber.

16. Lungs
• The lungs are located in the chest and are protected by the
rib cage.
• The lungs take in oxygen and they expel carbon dioxide. The
lungs deliver oxygenated blood to the heart where it is
pumped throughout the body and they receive
deoxygenated blood from the heart after blood travels
throughout the body.

17. Organ
Systems
• All organs of the body
work together to form
about a dozen organ
systems.

18. Organ Systems
1. respiratory system
2. digestive and excretory system
3. circulatory system
4. urinary system
5. integumentary system
6. skeletal system
7. muscular system
8. endocrine system
9. lymphatic system
10. nervous system
11. reproductive systems

19. Organ Systems
Organ system Description Component organs
Respiratory system breathing: exchange of oxygen and carbon dioxide
human nose, human mouth, paranasal sinuses, pharynx, larynx, trachea,
bronchi, lungs and thoracic diaphragm.
Digestive system /
excretory system
digestion: breakdown and absorption of nutrients, excretion of
solid wastes
human teeth, tongue, salivary glands, esophagus, stomach, liver, gallbladder
, pancreas, small intestine, large intestine, rectum and anus
Circulatory system
/cardiovascular/vascular
circulate blood in order to transport nutrients, waste,
hormones, O2, CO2, and aid in maintaining pH and temperature blood, heart, arteries, veins, capillaries
Urinary system /Renal/urinary
tract
maintain fluid and electrolyte balance, purify blood and excrete
liquid waste (urine)
kidneys, ureters, bladder and urethra
Integumentary system exterior protection of body and thermal regulation skin, hair, exocrine glands, fat, and nails
Skeletal system structural support and protection, production of blood cells bones, cartilage, ligaments and tendons.
Muscular system movement of body, production of heat skeletal muscles, smooth muscles and cardiac muscle
Endocrine system communication within the body using hormones made by
endocrine glands
hypothalamus, pituitary, pineal gland, thyroid, parathyroid and adrenal
glands, ovaries, testes
Lymphatic system
return lymph to blood stream, aid immune responses, form
white blood cells
lymph, lymph nodes, lymph vessels, tonsils, spleen, thymus
Nervous system sensing and processing information, controlling body activities
brain, spinal cord, nerves, sensory organs and the following sensory systems
(nervous sub-systems): visual system, Olfactory system, taste (
gustatory system), hearing (auditory system)
Reproductive system sex organs involved in reproduction ovaries, fallopian tubes, uterus, vagina, mammary glands, penis, testes,
vas deferens, seminal vesicles and prostate