Bones & Skeletal Structure

Team Sports 1

Bones & Skeletal Structure• Bones are a type of hard endoskeleton found in all

vertebrates. Bones give bodies their structure and protect internal organs.

• The adult human body has 206 bones. Infants are born with 300 bones--some consist of hard connective tissue and others are made of cartilage. Over time, the cartilage hardens and turns to bone and some bones fuse together. This accounts for the larger number of bones in children than in adults.

• By the time you are about 25 the process of cartilage hardening and bones becoming permanent is complete.

What are bones made of?• Bones are made up of three layers:– The outermost layer is called the periosteum. It is a thin

membrane that covers the bone and contains nerves and blood vessels that nourish the bone. Bones can grow and change and need oxygen and nutrients just like the rest of the body.

– The next layer is called compact bone. This is smooth and very hard.

– Under the compact bone are many layers of cancellous bone. Cancellous bone is spongy and not quite as hard as compact bone.

• In the middle of the bone is marrow, which is a jelly-like substance. Bone marrow produces blood cells.

Bones to know…• Spine- The series of

vertebrae extending from the base of the skull to the tip of the “tailbone” that forms the supporting axis of the body in vertebrate.

• Humerus- The long bone in the arm of humans extending from the shoulder to the elbow.

• Ulna- The bone of the forearm on the pinky side.

Bones to know…• Mandible-the bone of

the lower jaw • Tarsals-A set of seven

irregularly shaped bones. They are situated proximally in the foot, in the ankle area.

• Metatarsals- These bones connect the phalanges to the tarsals. There are five in number (one for each digit).

Things that make you go hmm…

• The hardest bone in your body is the jawbone or mandible. Your lower jawbone is the only bone in your head that you can move.

• The femur is the longest bone in your body and is responsible for 25% of your height.

• Each arm and leg have 30 bones apiece.• And although you can't see it, the smallest

bone in your whole body is in your head. The stirrup bone behind your eardrum is only .1 to .13 inches (2.5 to 3.3 millimeters) long!

Output Activity

• Trim copy of the skeleton to fit on your output page.

• Glue onto the appropriate page.

• Label and color code the 6 bones discussed in class.

• Crayon or colored pencil only please.