Skeletal System

What is the skeletal system?

Skeletal system consists of bones, teeth, joints, & structures that connect bones to other bones or muscles (ligaments, tendons, & cartilage).

Brainstorm … What are the

functions of the skeletal system?

(why is it important)

1. Support Many bones provide support, but long bones

especially important Acts as the frame for the rest of the body

long bones in legs help support the trunk other than long bones

the first vertebra supports the skull

2. Protection

Protect vital internal organs skull ->the brain rib cage ->heart, lungs, & abdominal organs

3. Movement Combination w/muscular system, the

skeletal system aids in movement Skeletal muscles are attached to bones by

tendons that act as a lever to move bones.

4. Mineral Storage Outer layers of bony tissues are used for the

storage of minerals (primarily calcium and phosphorus)

5. Blood Cell Formation & Energy Storage

Inner core of bone ->bone marrow Red marrow is a major site of blood cell & platelet

formation. Yellow marrow ->long bones & other mature

bones Yellow marrow consists mostly of fat & serves as

an energy reserve.

What is the purpose? Why is it important? Provides frame and support

Aids movementProtects vital organsMineral storageBlood cell formation

TURN AND TALK Which of the 5 functions is the most important and why?

3 cell types found in bones 1. Osteoblasts form a bone structure by secreting

collagen, become enclosed in the matrix, & develop into osteocytes. (BUILD NEW BONE)

2. Osteocytes - exchange of nutrients & wastes with blood (SITE OF CYTE EXCHANGE)

3. Osteoclasts secrete enzymes that digest bone. Bone is a living tissue that is continually remodeled in

response to the body’s need for calcium Osteoclasts are important in the development, growth,

maintenance, & repair of bone (CLASH to break DOWN OLD BONE)

Short bone – cube shaped, (think complex joins like the hock or knee) i.e. carpus and tarsus

Flat bone – plate of bone, (think thin and curved to protect organs) i.e. scapula, rib, skull

Irregular bone – complex shaped attached to muscles, i.e. vertebrae

Long bone – bone is longer that it is wide, i.e. femur, tibia, humerus, etc. (think legs/support)

NOT AS COMMON IN ANIMALS EXCEPT IN PAWS/HANDS Sesamoid – small, seed-shaped bone, i.e. proximal and

distal sesamoids, patella

TYPES OF BONE

How are bones classified? Long bones – femur Short bones – knee Flat bones – ribs, scapula Irregular bones – vertebrae Sesamoid bones –knee cap

Test Your KnowledgeCan you ID what “type” of bone each of these examples are?