The Basics
Core Functions
Axial vs. Appendicular
Bone Anatomy & Tissues
Bone Health & Diseases
100

This is the total number of bones found in a fully developed adult human skeleton.

What is 206?

100

This is the primary function of the skeletal system, which helps you stand upright rather than being a puddle on the floor.

What is support?

100

This part of the skeleton contains 80 bones along the center of the body, including the skull and rib cage.

What is the axial skeleton?

100

This dense, heavy outer layer makes up the exterior of the bone.

What is compact bone?

100

This condition, common in the elderly, involves the loss of bone tissue, making bones brittle.

What is osteoporosis?

200

These are the two primary "organs" that make up the entire skeletal system.

What are bones and joints?

200

Besides minerals like Phosphorus, bones are responsible for storing this vital mineral which is often found in dairy products.

What is calcium?

200

This part of the skeleton contains 126 bones and is primarily responsible for aiding with movement.

What is the appendicular skeleton?

200

This type of bone is found on the inside; it is lighter and porous, looking much like a kitchen tool used for cleaning.

What is spongy bone?

200

This inflammatory disease doesn't just hurt the bones; it specifically damages the joints and surrounding tissue.

What is arthritis?

300

This soft connective tissue found inside the pores of spongy bone is responsible for producing blood cells.

What is bone marrow?

300

This process occurs inside the red bone marrow of larger bones, creating the cells that carry oxygen through your body.

What is blood cell production?

300

These two "girdles" are the parts of the appendicular skeleton that connect your limbs to the center of your body.

What are the pelvic and shoulder girdles?

300

This tough, fibrous membrane covers and protects the very outer surface of the bone.

What is the periosteum?

300

Often appearing in teenagers, this condition is characterized by a side-to-side curve in the spine.

What is scoliosis?

400

The skeletal system works in conjunction with this other system to allow the body to move.

What is the muscular system?

400

Bones help maintain this stable internal environment by absorbing or releasing calcium into the blood.

What is homeostasis?

400

The skull, vertebrae, and this bone structure make up the three main parts of the axial skeleton.

What is the rib cage?

400

These specific connective tissues attach bone to bone.

What are ligaments?

400

This disease causes the softening of bones and is usually caused by a lack of Vitamin D.

What is osteomalacia?

500

Humans have five classifications of bones: Long, Short, Irregular, Flat, and this final type, which includes the patella (kneecap). 

What are sesamoid bones?

500

The skeletal system acts as an "anchor" for these, which pull on bones to allow the body to move.

What are skeletal muscles?

500

While the adult human skeleton has 206 bones total, this specific number of bones is found in the axial portion.

What is 80?

500

These connective tissues attach muscle to bone, allowing the skeleton to move when muscles contract.

What are tendons?

500

It takes between 25 and this many pounds of pressure to cause a break or fracture in an average bone.

What is 160 pounds?