Skeletal System

What are the 5 Functions of the Skeletal System? 1. Movement: Skeletal system provides points of attachment for muscles. Your legs and arms move when the muscles pull on the bones. 2. Support: The backbone is the main support center for the upper body. It holds your head up and protects your spinal cord. Muscle attached to bones!!

What are the 5 Functions of the Skeletal System? 3. Protection: The bones of your skull protect your brain. Your ribs protect your lungs and heart from injury. 4. Makes Blood: Red and white blood cells are formed by tissue called marrow, which is in the center of the bone.

What are the 5 Functions of the Skeletal System? 5. Storage: Bones store minerals, such as calcium and phosphorus, for use by the body

What are the Two Major Skeletal System Parts? Axial Skeleton: The axial skeleton includes the skull, spine, ribs and sternum. Appendicular Skeleton: The appendicular skeleton includes the appendages of the body, which are the shoulders, arms, hips, and legs. What are the Two Major Skeletal System Parts?

What are the Basic Bone Shapes? Four basic bone shapes: 1. Long- arms, legs and fingers 2. Short- wrist and ankles 3. Flat- skull and sternum 4. Irregular- spine

What is the Structure of Bone? Typical Four Layers: Periosteum: Covers Bones Compact Bone: Lies beneath the periosteum Spongy Bone: Lies beneath the compact bone Bone Marrow: Fills the gaps between the spongy bone

What is the Structure of Bone? Bones are complex living structures that undergo growth and development. A thin tough outer membrane covers the bone. Beneath the outer membrane is a layer of compact bone (hard and dense, but not solid – it is filled with holes and has small canals for blood vessels and nerves). What is the Structure of Bone?

What is the Structure of Bone? Inside the compact bone is a layer of spongy bone. It has many small spaces, is light weight, but strong. Spongy bone is also found at the ends of bones.

What is the Structure of Bone? In the spaces of many bones there is a soft connective tissue called marrow. Two types of Marrow: Red Marrow produces most of the body’s blood cells. Yellow Marrow stores fat that can serve as an energy reserve.

How Strong are Bones? The structure of bones make it both strong and light weight. 20 % of an adults body weight is bone. Bone is made up of 2 minerals: Calcium Phosphorus

As an infant, most of your skeleton is cartilage. Cartilage is a strong flexible tissue. Over time the cartilage is replaced by solid bone, usually complete by the time you stop growing. Not all cartilage is replaced in adults. Many joints contain cartilage, protecting the ends of bones (ears and the end of the nose is also cartilage). How Do Bones Develop?

Joints A joint, or articulation, is the place where two bones come together. Fibrous- Immovable:connect bones, no movement. (skull and pelvis). Cartilaginous- slightly movable, bones are attached by cartilage, a little movement (spine or ribs). Synovial- freely movable, much more movement than cartilaginous joints. Cavities between bones are filled with synovial fluid. This fluid helps lubricate and protect the bones.

The Synovial Joint Slide 5.51 Figure 5.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Synovial Joints Based on Shape Figure 5.29a–c Slide 5.52a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Synovial Joints Based on Shape Figure 5.29d–f Slide 5.52b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Joints Hinge- A hinge joint allows extension and retraction of an appendage. (Elbow, Knee)

Ball and Socket- A ball and socket joint allows for radial movement in almost any direction. They are found in the hips and shoulders. (Hip, Shoulder)

Gliding- In a gliding or plane joint bones slide past each other Gliding- In a gliding or plane joint bones slide past each other. Mid-carpal and mid-tarsal joints are gliding joints. (Hands, Feet)

Saddle- This type of joint occurs when the touching surfaces of two bones have both concave and convex regions with the shapes of the two bones complementing one other and allowing a wide range of movement. (Thumb)