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 a passive movement while muscle as an active movement Mineral storage- calcium & phosphate Blood cell formation- hematopoiesis When you were born you had over 300 bones! As you grow up bones fuse (grow) together into 206 bones.

How Bones Grow When a baby is born, its body contains 300 bones. Baby bones are made of a special material called cartilage. It is soft and flexible. Your earlobes and nose are made of cartilage. During puberty some bones start to grow together to produce the 206 adult skeleton. Until people reach between 17 and 21 years of age, the cartilage has completely hardened into bone. Once completed, there can be no more growth.

Human skeleton

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

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

Appendicular Skeleton Humerus Ulna Radius 8 Carpals 5 Metacarpals 14 Phalanges

Humorus

Ulna & Radius

Hand Bones

Appendicular Skeleton Pelvis

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

Male vs Female Pelvis                                                   Female Pelvic Girdle Male Pelvic Girdle

Appendicular Skeleton The Lower Limb (Legs) Femur Patella Tibia Fibula 7 Tarsals 5 Metatarsals 14 Phalanges

Femur

Patella

Tibia & Fibula

Foot phelangies metatarsals tarsals tarsals metatarsals phelangies

The Joints The place where two bones meet is called a joint. There are two types of joints in every person's body: fixed joints and moving joints.

Immovable Joints (synarthrosis) suture pubis symphisis

Slightly Movable Joint (ampharthrosis)

Types of Joints in the Human Body

Moving joints Moving joints are enable you to twist, bend, and move many different parts of your body. Types: 1. Hinge joints, like in your knee and elbow, enable movement similar to the opening and closing of a hinged door. 2. Ball and socket joint (shoulders and hips). It allow for lots of movement in every direction. 3. Ellipsoidal joints, such as the joint at the base of your index finger, allow bending and extending, rocking from side to side, but rotation is limited.

Moving joints 4. Gliding joints occur between the surfaces of two flat bones that are held together by ligaments. Some of the bones in your wrists and ankles move by gliding against each other. 5. Pivot joint in your neck allows you to turn your head from side to side. 6. The only Saddle joints in your body are in your thumbs. The bones in a saddle joint can rock back and forth and from side to side.

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

MUSCLES A type of elastic tissue (sort of like the material in a rubber band). Thousands, or even tens of thousands, of small fibers make up each muscle. Types

MUSCLES Characteristics Skeletal muscle Smooth muscle Cardiac muscle Shape Long, cylindrical cell long, narrow "spindle" shaped cells Long, cylindrical, branch shaped cell Number of nucleus Many nuclei One in the middle of the cell Work Voluntary Involuntary Movement Fast, unorganized and tired easily Slow, organize, not easily tired Organize and not easily tired