Please write the answer in your notes as a complete sentence…. Ex. It is important to know how and why the human body systems work because…

1. Skeletal 2. Muscular 3. Circulatory 4. Nervous 5. Respiratory 6. Digestive 7. Excretory 8. Endocrine 9. Reproductive 10. Lymphatic (Immune)

 The purpose of all body systems working together is to maintain homeostasis  Homeostasis is a state of equilibrium (balance)

Most human babies are born with 300 bones. However, most adults have 206 bones in their body. Why or How does this change occur?

1. Understand the characteristics and function of the skeletal system 2. Identify different bone types and tissues 3. Recall the organization of the skeleton 4. Describe different types of joints and how they work

 “Firm but Flexible” (What would happen if bones had no elasticity?)  Porous (How do bird’s bones allow them to fly?)

1. Gives shape and support 2. Protects organs 3. Provides a place for muscle attachment and movement 4. Blood cell formation 5. Calcium (Ca) and Potassium (K) are stored

 A tough, tight fitting membrane that covers the outsides of bones.

 Compact ◦ Directly under periosteum ◦ Hard, Strong layer ◦ Gives bone strength ◦ Blood vessels  Spongy Bone ◦ Located at the end of long bones ◦ Very porous and lightweight ◦ Cavities filled with marrow

 The ends of bones are covered with a smooth, slippery, thick layer of tissue.  Acts as a shock absorber in joints (where two bones meet)  Also makes movement easier by reducing friction.

 Read p. 152  What was the skeleton made of before birth? ◦ Cartilage  What are bone forming cells called? ◦ Osteoblasts  How many bones did you have at birth? ◦ Over 300  How many bones do you have now? ◦ 206

 Bone Types: 1. Long 2. Short 3. Flat 4. Irregular (5. Sesamoid)

 Long Bones ◦ Longer than they are wide ◦ Femur, Tibula, Fibula (leg) ◦ Radius Ulna (arm) ◦ Metacarpals & Metatarsals (hands) ◦ Phalanges (feet)

 Short Bones ◦ As wide as they are tall ◦ Carpus (wrist) ◦ Tarsus (ankle) ◦ Patella (knee cap)

 Flat Bones ◦ Functions as protection or broad surface for muscle attachment ◦ Cranium ◦ Sternum ◦ Rib cage ◦ Scapula

 Irregular Bones ◦ Cannot be classified as long or short ◦ Serve various purposes ◦ Vertebrae ◦ Pelvis ◦ Hyoid ◦ Coccyx

 Any place where two or more bones meet

1.Ball and Socket 2.Hinge 3.Pivot 4.Gliding 4 Different Types of Joints

 Allow twisting and turning movements. ◦ Some of these joints are the shoulder and the hip. The shoulder joint is the most flexible joint in the entire body. It allows movement in any direction.

 Allows movement in a certain spot to take place.  This joint is similar to the opening and closing of a door.  Some examples of hinge joints are the elbow, knee, ankle and joints between the fingers. Hinge joints allow the body parts to bend and straighten.

 Allows turning. ◦ In the pivot joint, the bone turns in a circle (or half- circle). An example is the neck, which allows partial turning of the head at about a 180 degree angle.

 Allows bones to move back and forth against each other. ◦ An example of this is the backbone, or the vertebrae. ◦ The bones in the backbone can move freely move against each other, allowing a person to move in a wide range of motions with their spine.

 Arthritis: inflammation of the joint, causes swelling and stiffness  Osteoporosis: thinning of bone tissue and loss of bone density

 Positive choices 1. Maintain a healthy weight 2. Eat a diet rich in calcium and vitamin D 3. Don’t smoke 4. Exercise 5. Limit the amount of sodium intake