The Skeletal System

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The Skeletal System
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The Skeletal System

• Definition
• 206 bones in our body held together by connective
  tissues
• Cartilage
• Tendons
• Ligaments

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CONNECTIVE TISSUES

• CARTILAGE
• Smooth, slippery, thick layer of tissue
• Covers the ends of bones
• Flexible and acts as a shock absorber
• Makes movement easier by reducing friction

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CONNECTIVE TISSUES

• LIGAMENT
• an elastic band of tissue that connects bone to
  bone and provides stability to the joint.

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CONNECTIVE TISSUES

• TENDON
• band of tissue that connects muscle to bone

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The Skeletal System

• Function
• forms an internal, living framework that
• provides shape and support
• protects internal organs
• moves bones
• forms blood cells
• stores calcium and phosphorous compounds for
  later use

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Bones

• Made of layers of living tissue
• Covered with a tough, tight-fitting membrane
  called the periosteum

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FORMATION OF BONES

• All bones start off as cartilage
• Bone replaces cartilage at about 7 months before
  birth up until 23 years of age
• Contain minerals
• Calcium
• Phosphorus
• Parts of bone
• Compact
• Spongy

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Compact Bone

• Directly under the periosteum
• Hard, strong layer
• Gives bones strength
• Contains deposits of calcium phosphate
• Contains bone cells and blood vessels

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Spongy Bone

• Located at the ends of long bones
• Has many small, open spaces that make bones
  lightweight
• Filled with a substance called marrow
• yellow composed of fat cells
• red produces red blood cells

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Joints

• Definition
• Any place where two or more bones come together

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Joints

• Kept far enough apart by a thin layer of
  cartilage so that they do not rub against each
  other as they move
• Bones are held in place at joints by a tough band
  of tissue called ligament

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Types of Joints

• Immovable
• Skull
• Pelvis
• Moveable
• Pivot
• Ball socket
• Hinge
• Gliding

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Types of Joints

• Ball and Socket Joint
• Bone with a rounded end that fits into a cuplike
  cavity on another bone
• Ex. Hip, Shoulder

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Types of Joints

• Pivot Joint
• One bone rotates in a ring of another bone that
  does not move
• Ex. Base of skull, Ulna in your forearm

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Types of Joints

• Hinge Joint
• Back-and-forth movement like hinges on a door
• Ex. Elbow ,Knee

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Type of Joints

• Gliding Joint
• One part of a bone slides over another bone
• Ex. Hand, Foot, Scapula and Clavical