The skeletal system is made up of bones and cartilage and has several important functions including support, movement, protection of organs, blood cell production, and mineral storage. It consists of 206 bones divided into the axial and appendicular skeleton. Compact bone is dense and strong while spongy bone is lightweight. Cartilage provides flexibility and connection between bones. The skeletal system works with other body systems by providing protection and attachment sites while receiving nutrients, hormones, and waste removal in return.

1. The Skeletal System and its
Functions

2. Made up of bones and cartilage, the human skeletal system has
many important functions, including support, movement, protection
of internal organs, blood cell production and mineral storage.
FUNCTIONS:
• Supports the body
• Protects the body’s internal parts or organ
• Helps move the body
• Stores minerals
• Produces blood cells

3. The adult skeletal system consist of 206 bones (as well as a network
of tendons, ligaments, and cartilage that connects them) and can be
divided into 2 parts:
AXIAL SKELETON
Includes bones of the skull, vertebral column, ribs, sternum, sacrum,
coccyx, in total of 80 bones.
APPENDICULAR SKELETON
Includes the 126 bones of the shoulder, pelvis, and the upper and
lower extremities.

4. COMPACT BONE
Is hard, dense, mineralized tissue that gives bones its strength. It
usually surrounds the spongy bone tissue.
 SPONGY BONE
A porous layer of tissue that makes the bone lightweight. Its spaces
usually contains blood vessels and bone marrow, a soft tissue that
produces blood cells.

5. A flexible connective tissue that forms the embryonic skeleton. Most
is created into bones during fatal and childhood development. In
adults, cartilage is found in movable joints, in the ears, nose, trachea,
and other structures. It also connects the ribs and the sternum.

6. How The Skeletal System Works With
Other Body Systems

7. SKELETAL SYSTEM
INTEGUMENTARY SYSTEM
Bones give support for skin.
IN EXCHANGE:
Skin protects bones, helps provide vitamin D for calcium ions
(𝐶𝑎2+ ) absorption.

8. SKELETAL SYSTEM
MUSCULAR SYSTEM
Bones provide attachment site for muscles, and stores calcium ions (𝐶𝑎2+ ) for
muscle function.
IN EXCHANGE:
Muscular contraction causes the bones to move joints and helps protects the
bones.

9. SKELETAL SYSTEM
NERVOUS SYSTEM
Bones protect sense organ, brain, and the spinal cord; and store calcium ions
(𝐶𝑎2+ ) for nerve functions.
IN EXCHANGE:
Receptors send sensory input from bones to central nervous system.

10. SKELETAL SYSTEM
ENDOCRINE SYSTEM
Bones provide protection for glands and store calcium ions (𝐶𝑎2+
) used as
second messenger.
IN EXCHANGE:
Growth hormones regulate bones development, the parathyroid and
calcitonin regulate calcium ions (𝐶𝑎2+ ) content.

11. SKELETAL SYSTEM
CARDIOVASCULAR SYSTEM
Rib cage protects the heart, red bone marrow produces blood cells, and bones
store calcium ions (𝐶𝑎2+ ) for blood clotting.
IN EXCHANGE:
Blood vessels deliver nutrients and oxygen to bones and carry away waste.

12. SKELETAL SYSTEM
LYMPHATIC OR IMMUNE
SYSTEM
Red bone morrow produces white blood cells involved in immunity.
IN EXCHANGE:
Lymphatic vessels pick up excess tissue fluid; immune system protects
against infection.

13. SKELETAL SYSTEM
RESPIRATORY SYSTEM
Rib cage protects lungs and assist breathing; bones provide attachment sites
for muscles involved in breathing.
IN EXCHANGE:
Gas exchange in lings provides oxygen and rids body of carbon dioxide.

14. SKELETAL SYSTEM
DIGESTIVE SYSTEM
Jaws contain teeth that chew food and the hyoid bone assists swallowing.
IN EXCHANGE:
Digestive track provides calcium ions (𝐶𝑎2+ ) and other nutrients for bone growth and
repair.

15. SKELETAL SYSTEM
URINARY SYSTEM
Bones provide support and protection.
IN EXCHANGE:
Kidneys provide active vitamin D for calcium ions (𝐶𝑎2+ ) absorption and
help maintain blood level of calcium ions needed for bone growth and repair.

16. SKELETAL SYSTEM
REPRODUCTIVE SYSTEM
Bones support and protection of reproductive organs
IN EXCHANGE:
Sex hormones influence bone growth and density in males and females