1 Chapter 9 The Skeletal System Functions of the Skeletal System (Jobs)Shape and Support: The backbone is the main support center for the upper body. It holds your head up and protects your spinal cord. Protection: The bones of your skull protect your brain. Your ribs protect your lungs and heart from injury.

2 5 Functions of the Skeletal System (cont.)3. Movement: Skeletal system provides points of attachment for muscles. Your legs and arms move when the muscles pull on the bones. 4. Makes Blood Cells: Red and white blood cells are formed by tissue called bone marrow, which is in the center of bones.

3 5 Functions of the Skeletal System (cont.)5. Storage: Bones store minerals, such as calcium, phosphorous and other minerals for use by the body to build strong teeth and bones. Good sources are dairy products, cheese, green leafy vegetables.

4 Structure (parts)of the SkeletonBones Joints Cartilage Ligaments

5 Bones Humans have 206 bones. You are born with 270.Newborn infants have more cartilage than bone at birth. cartilage is more pliable than bone. Bones of the skull and vertebrae (backbone) fuse as they get older.

6 Composition of Bones (what they’re made of)Bones are a combination of minerals, proteins, water, and living matter (cells). Minerals (calcium and phosphorous) give the bones their strength and hardness. Protein gives them their flexibility.

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8 Bone Structure Four Layers:Periosteum: Protective layer that Covers Bones Compact Bone: very dense, heavy, allows muscles to attach, nerves and blood vessels run through it

9 Bone Structure (cont.) Spongy Bone: less dense, lighter, has nerves and blood vessels, keeps the entire bone light Bone Marrow: found in the center of bones and makes blood cells

10 DQ # 4 What is the difference between a hairline fracture and a stress fracture? Hairline- thin break often missed in an x-ray. Usually heals with rest. Stress – occurs over time by putting to much pressure on a bone. Quiz Friday – Identify the location, common name, and scientific name of the 20 bones.

11 Bones of the Skeleton Cranium (skull)Protects your brain and makes up the structure of your face Mandible (lower jaw bone) Only bone in your head that moves and allows you to talk and chew.

12 Vertebrae (spine or backbone)Made of 24 smaller bones stacked on top of each other from the bottom of the skull to the pelvis. Allows you to twist and bend, holds your body upright, and protects your spinal cord.

13 Between each the vertebrae are discs made of cartilageBetween each the vertebrae are discs made of cartilage. Cartilage is a tough flexible tissue. These discs keep the vertebrae from rubbing against each other and acts as a cushion to protect your spine.

14 Sacrum (lower back) a triangular bone in the lower back Coccyx (tailbone) bottom portion of the vertebrae

15 Ribcage (Ribs) Acts like a cage of bones around your chest that protects your heart, lungs, and liver Most people have 12 pairs of ribs attached to the back of their spine

16 Sternum (breast bone) a strong bone in the center of your chest that holds the first 7 pairs of ribs in place.

17 Scapula (shoulder blade)A large, triangle-shaped bone on the back corner of each side of the ribcage. Location where your arms are attached Clavicle (collar bone) Connects the top of your sternum to the scapula

18 Bones of the arm Humerus ( upper arm bone) Radius (lower arm bone)

19 The hand is made of three sections.Carpal (wrist bone) Metacarpal (hand bone) Phalanges (fingers)

20 Pelvis (hipbone) bowl shaped bone that supports your spine, digestive and reproductive organs. Legs are attached. Hint: Elvis moves his pelvis

21 Bones of the leg Femur (thigh bone) and longest bone in your body Patella (knee cap) triangle shaped surrounding knee Tibia (shin bone)

22 The foot is made of three sectionsTarsal (ankle bone) Metatarsal (foot bone) Phalanges (toes) tarsal- Hint: Tarsals are near your Toes

23 Joints of the Body Joints-location where bones meet and allows movementBall and Socket Joint Round end of bone fitting within another bone. Ex. Shoulder and Hip

24 Hinge Joint-Movement in one direction like a door.Ex. Knee and Elbow

25 Pivot Joint - Bone resting atop another bone permitting free movement.Ex. Neck, Wrist and Ankles

26 Fixed Joint bones meet but do not moveEx. Skull

27 Ligaments A tissue that connects a bone to a bone

28 Problems of the Skeletal SystemFracture: Break in the bone Dislocation: Bone is out of joint

30 Scoliosis: Curvature of the spineOsteoporosis: Brittle bones often due to a lack of calcium