Skeletal System

Function of the Skeletal System Support- framework that supports body and cradles its soft organs Protection- for delicate organs, heart, lungs, brain Movement- bones act as levers for muscles Mineral storage- calcium & phosphate Blood cell formation- hematopoiesis

Types of Bones Long Bones- metacarples, metatarsals, phelangies, humerus, ulna, radius, tibia, fibula Short Bones- carpals, tarsals Flat Bones- rib, scapula, skull, sternum Irregular Bones- vertebrae, some facial bones Sesamoid- patella

Bone Classification

Anatomy of a Long Bone spongy bone Proximal compact bone epiphysis Endosteum diaphysis epiphyseal line yellow marrow Sharpey’s fibers Distal epiphysis periosteum hyaline cartilage

Axial Skeleton

Appendicular Skeleton

Axial Skeleton Cranium Facial Bones Anterior View

Axial Skeleton Cranium Facial Bones Lateral View

Axial Skeleton Posterior View

Axial Skeleton Inferior View

Sinal Cavities Frontal Sinus Ethmoid Sinus Sphenoid Sinus Maxillary Sinus Warm and moisten air Lighten the skull Enhance voice resonance

The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12) Axial Skeleton The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12) Lumbar Vertberae (5) Sacrum Coccyx

Cervical Vertebrae

The Thoracic Cage Sternum True Ribs (7) False Ribs (3) Axial Skeleton The Thoracic Cage Sternum True Ribs (7) False Ribs (3) Floating Ribs (2)

Axial Skeleton Sacrum & Coccyx

Bones of the Pectoral Girdle Appendicular Skeleton Bones of the Pectoral Girdle

The Upper Limb (Forelimb) Appendicular Skeleton The Upper Limb (Forelimb) Humerus Ulna Radius Carpals Metacarpals Phalanges

Humorus

Ulna & Radius

Hand Bones

Appendicular Skeleton Pelvis

Appendicular Skeleton Pelvis (lateral view) Ilium Acetabulum Obturator foramen Pubis Ischium Ischium

Appendicular Skeleton The Lower Limb (Legs) Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

Femur

Patella

Tibia & Fibula

Foot phelangies metatarsals tarsals tarsals metatarsals phelangies

Fetal Skull

Immovable Joints (synarthrosis) Fibrous Joints Immovable Joints (synarthrosis) suture pubis symphisis

Slightly Movable Joint (ampharthrosis) Cartilagenous Joints Slightly Movable Joint (ampharthrosis)

(diarthrosis)- freely moveable Synovial Joints (diarthrosis)- freely moveable pelvis ligaments femur

Synovial Joints joint capsule pelvis hyaline cartilage synovial cavity femur

Knee Joint

Synovial Joint Movement Extension Rotation Flexion Adduction Abduction

275 bones 12 weeks (6-9 inches long) Fetal Skeleton 275 bones 12 weeks (6-9 inches long)

bone cartilage calcified cartilage epiphyseal line epiphyseal plate Fetus: 1st 2 months Endochondral Ossification 2o ossification center bone cartilage calcified cartilage Just before birth epiphyseal line epiphyseal plate Childhood Adult

Bone cells that aid in remodeling Osteoblast Builds new bone Mature bone cell Osteocyte OsteoblastsOsteoblasts are responsible for building new bone and lie at the centre of bone physiology. Their functions include the synthesis of collagen and the control of mineralisation. OsteoclastsOsteoclasts are specialised cells that resorb bone. They work by sealing off an area of bone surface then, when activated, they pump out hydrogen ions to produce a very acid environment, which dissolves the hydroxyapatite. OsteocytesBone adapts to applied forces by growing stronger in order to withstand them; it is known that exercise can help to improve bone strength. Osteocytes are thought to be part of the cellular feed-back mechanism which directs bone to form in the places where it is most needed. They lie within mineralised bone and it is thought that they may detect mechanical deformation and mediate the response of the osteoblasts. Osteoclast Eats bone

Bone Repair: Electrical stimulation of the fracture site: Increases speed and completeness of healing The e- stimulation inhibits PTH and slow osteoclasts down from reabsorbing bone 2. Ultrasound treatment: Daily treatments reduce healing time of broken bones by 25-35% 3. Free vascular fibular graft technique: Transplant fibula in arm Gives good blood supply not available in other treatments 4. Bone substitutes: Crushed bone from cadaver- but risk of HIV and hepatitis Sea bone- coral Artificial bone- ceramic

Repair of Fractures hematoma callus bony callus bone remodeling

Diseases of the Skeletal System: Osteoporosis- bone reabsorption outpaces bone deposit; bones become lighter and fracture easier Factors: age, gender (more in women) estrogen and testosterone decrease insufficient exercise (or too much) diet poor in Ca++ and protein abnormal vitamin D receptors smoking

Osteoporosis 29 40 84 92

Diseases of the Skeletal System: Rickets- vitamin D deficiency Osteomalacia- soft bones, inadequate mineralization in bones, lack of vitamin D Pagets Disease- spotty weakening in the bones, excessive and abnormal bone remodeling Rheumatoid arthritis- autoimmune reaction

INQUIRY What is a fontanel? How many bones in the adult skeleton? What is the difference between the appendicular and axial skeleton? What is a meniscus? Demonstrate adduction. Weight bearing vertebrae are called? What does an osteoclast do/ Extra Credit: 1-page reaction paper on bipedalism and problems associated with our human frame. Attach article. Turn in 1-week from today. http://www.youtube.com/watch?v=DSHoonPWwXQ