What are the five functions of the skeletal system?

206 individual bones Connective tissue (osseous tissue) Lightweight, but strong

1. Framework/Support Provides shape to the body 2. Protection Soft, delicate internal organs

3. Allows Movement and Anchorage of Muscles (Levers) Skeletal muscles attach to the skeleton Ligaments/Tendons Work with bone Ligaments Fibrous bands Connect bones to bones and cartilage Joints are bound together by ligaments Tendons Fibrous cords Connect muscles to bone

4. Mineral storage Calcium Phosphorus In Malnutrition Pulls from bones (Homeostasis) 5. Hemopoiesis (Production of blood cells) Red blood cell formation in the red marrow Long Bones Sternum Ilia

What are the four types of bones?

4 Types Long Bones – arms & legs Flat Bones – skull & ribs Irregular Bones – spinal column Short Bones – hand & foot Degree of Movement Determined by Bone Shape & Joint Structure

Osteocytes microscopic cells mature bone cells 35% Organic/ 65% Inorganic Organic Collagen – a fibrous protein material Jellylike material between collagen fibers give it a degree of flexibility Prevents bone damage Inorganic Mineral Salts – calcium, phosphate, calcium carbonate, calcium fluoride, magnesium phosphate, sodium oxide, and sodium chloride Give bone its hardness and durability Helps resist crushing under pressure

Embryonic Skeleton Collagenous protein fibers Secreted by the osteoblasts Eighth Week Ossification begins Mineral matter starts to replace previously formed cartilage creating bone Infant bones Soft and pliable Incomplete ossification - s oft spot – fontanel As bone ossifies Babies able to bare weight

Throughout Life Remodeling Resorption and Formation Resorption Old bone broken down and removed by Osteoclasts – bone cells that secrete enzymes – splitting the bone materials Formation New bone laid down by Osteoblasts Avg. Females 18 Avg. Males 21 Formation occurs any time of injury or break

Diaphysis Hollow cylinder Hard compact bone Strong and light Epiphysis Each end of the Diaphysis Proximal Distal Medullary Canal Center of shaft Filled yellow marrow Storage area for fat cells Cells that form WBC or Leukocytes Blood vessels Endosteum Inner lining of marrow canal that keep the marrow intact Some bone growth

Red Marrow End of long bones, vertebrae, ribs, and sternum Red blood cell formation Platelets and some WBC Periosteum Tough outer covering of bone Contains Blood vessels Lymph vessels Nerves Osteoblasts -Necessary for bone growth, repair and nutrition

Using the picture in your text – page 89 Label and color code a long bone Include Diaphysis - Grey Epiphysis - Blue Medullary canal - Orange Yellow marrow – Yellow Red marrow - Red Periosteum – Black/Dr Grey Endosteum - Green

What bones make up the Axial Skeletal System?

Two Main Axial Skeleton Skull Spinal column Ribs Sternum (Breastbone) Hyoid Bone – U-shaped bone in neck attached to the Tongue

Upper extremities Shoulder Girdle Arms Wrists Hands Lower extremities Hip Girdle Legs Ankle Feet

Cranium & Facial Bones Cranium During Infancy held together by Sutures – then ossifies and turns hard Houses & protects the brain Facial Guard & Support Eyes, Ears, Nose, and Mouth

8 Cranium Frontal, Parietal, Temporal, Occipital, Ethimoid, Sphenoid 14 Facial 5 nasal, 2 maxallas (upper jaws), 2 lacrimal, 2 zygomatic (cheek bones), 2 palatine (hard palate of the mouth), and the mandible Skull contains spaces Sinuses Mucous Membranes Swollen Inflamed Foramina In bottom of skull, spinal cord, nerves etc pass through to the brain Foramina

Strong/ Flexible Supports the head Provides attachment for the ribs Encloses and protect the spinal cord

Small bones/vertebrae Separated by intervertebral disks Act as cushions/shock absorbers Thinner as we age Result in loss of height Verebrae Cervical - 7 Thoracic - 12 Lumbar - 5 Sacrum – (five fused bones) Coccyx – (four fused bones) aka tail bone

Sternum (Breastbone) Helps protect thoracic area of body Ribs 12 pairs of Ribs First 7 true Ribs 3 Pair of False Ribs 2 Pair of Floating Ribs