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 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?  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 ► Yellow  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

How Do Bones Develop?  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).

Clavicle or Collarbone ► The clavicle, or collar bone, holds the shoulder joint away from the rest of the upper body and is only as thick as your little finger.

Scapula ► The scapula is located on the back side of the ribcage and helps provide part of the shoulder joint and movement for the arms.

Vertebral Column or Spinal Cord 1) The cervical region (neck bones) 1) The cervical region (neck bones) 2) The thorasic region (what the ribs attach to) 3) The lumbar region (the lower part of the back) 3) The lumbar region (the lower part of the back)

Coccyx and Sacrum

Humerus (Upper Arm Bone)

Radius and Ulna ► Radius on Top ► Ulna on Bottom

Carpals or (Wrist Bones)

Metacarpals (Top of Hands)

Phalanges (Little Fingers)

Rib Cage

Sternum (Breastbone)

Pelvis

Femur (Largest Bone in the Body)

The Tibia and Fibula

Tarsals

Metatarsals

Phalanges

What are Joints? A joint is a place where two bones come together. Joints allow the bones to move in different ways. Two types of joints: Immovable Movable

What are Immovable Joints? A joint that allows little or no movement

What are Movable Joints? Most of the joint are movable joints. Allow the body to move in a wide range of movements. Bones in movable joints are held together by strong connective tissue called ligaments. Four types of movable joints: Hinge Ball-and-socket Pivot Gliding

What is a Ball-and- Socket Joint? ► Round end of bone fitting snuggly within another bone.  Ex. Shoulder and Hip ► Allows the greatest range of motion.  The ball-and-socket joint allows you to swing your arm freely in a circle.

What is a Hinge Joint? ► Movement in one direction like a door.  Ex. Knee and Elbow ► Allows forward or backward motion.

What is a Pivot Joint? ► Bone resting atop another bone permitting free movement.  Ex. Neck, Wrist and Ankles ► Allows one bone to rotate around another.  Allows you to turn your head

What is a Gliding Joint? ► Allows one bone to slide over another.  Ex. Knuckles, wrist, ankle ► Allows your to bend and flex as well as make limited side to side motions.

What is a Ligament? ► Connects bone to bone.

What is a Tendon? ► Attaches muscles to bones.