Transcript sacrum bone
Skeletal System Functions • Support - provides hard framework for soft tissue • Protection of underlying organs • Brain, Eyes, Inner ear structures, heart & lungs, kidneys • Movement - skeletal muscles use bones as levers • Storage. • Calcium and Phosphorous • Stored then released as needed. • Fat stored in marrow cavities • Blood cell production (Hematopoiesis). Bone marrow that gives rise to blood cells and platelets Bone Shapes • Long • Ex. Upper and lower limbs • Short • Ex. Carpals and tarsals • Flat • Ex. Ribs, sternum, skull, scapulae • Irregular • Ex. Vertebrae, facial Classification of Bones Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone • Examples: Femur, humerus Classification of Bones Short bones Generally cube-shape Contain mostly spongy bone Examples: Carpals, tarsals Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5.4b Classification of Bones Flat bones Thin and flattened Usually curved Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5.5a Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Example: Vertebrae and hip Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5.5b Skeletal system includes both: • Axial skeleton • Skull • Vertebral column • Thoracic cage • Appendicular skeleton • Pectoral and pelvic girdles • Upper and lower limbs The Axial Skeleton Figure 7.1b Cranial and Facial Subdivisions of the Skull Figure 7.2 The Adult Skull(ant view) Figure 7.3d The Adult Skull(sup & post view) Figure 7.3a, b The Adult Skull(lateral view) Figure 7.3c The Adult Skull( inf view) Skull(cranial fossa) Figure 7.4b Newborn vs. Adult Major Differences Fontanelles Pos & sphenoidal=2-3month after birth Mastoid=1year Ant=1-2 year Unfused Structures Sutures Unfused Structures frontal parietal occipital Paranasal Sinuses Functions: lightening the weight of the head Give resonance and amplification to voice humidifying and heating inhaled air serving as a crumple zone to protect vital structures in the event of facial trauma Remember that the Axial skeleton includes: Skull Vertebral column Thoracic cage Axial skeleton is shown in green The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12) Lumbar Vertberae (5) Sacrum Coccyx The Vertebral Column • Fetus and infant: 33 separate bones, or vertebrae • Adult: 24 vertebrae • Inferior 9 have fused forming • The sacrum (5) and • The coccyx (4) • Four spinal curves • Primary (accommodation) curves = thoracic and sacral • Secondary (compensation) curves = lumbar and cervical Curvatures of the Spine • Scoliosis side-to-side, lateral curve Lordosis • Abnormal inward curve of the lumbar region Kyphosis Abnormal curvatures Structure of a typical vertebra • Typically has a body and vertebral arch • Superior and inferior articular processes • Separated by intervertebral discs Vertebral Anatomy Vertebral regions • Cervical • Has small body • Large relative size of vertebral foramen • Costal processes with transverse foramina • Notched spinous processes The Cervical Vertebrae C1 (atlas) • Without body • Have lateral masses with tow arc post and ant • Have an post tubercle C2 (axis) Thoracic vertebrae The Thoracic Vertebrae • Heart-shaped body • Long slender spinous processes • Articulations for ribs Lumbar Vertebrae • Most massive • Least mobile • Subjected to great stresses sacrum • Fusion of 5 sacral vertebra • Surfaces: • • • Anterior(pelvic) Posterior Lateral • Base • apex The Sacrum and Coccyx • Protects reproductive, digestive and urinary organs Thoracic cage • Thoracic vertebrae • Ribs • Sternum • Ribs and sternum forms the rib cage Sternum • Three parts • Manubrium • Body • Xiphoid process Ribs • 12 Pairs • True ribs • First 7 pairs • Attach to thoracic vertebrae and sternum • False ribs • Next 8,9,10 pairs • Attach to the cartilage of the ribs above • Floating ribs • Last 2 pairs of false ribs • Have no attachment in the front The Thoracic Cage The Thoracic Cage Typical rib • Has a head, neck, tubercle and a body Vertebral and Sternal Articulations Appendicular Skeleton Appendicular Skeleton: Pectoral Girdle (Shoulder) Appendicular Skeleton: Pelvic Girdle • Hip bones • Composed of three pair of fused bones • Ilium • Ischium • Pubic bone • The total weight of the upper body rests on the pelvis • Protects several organs • Reproductive organs • Urinary bladder • Part of the large intestine Hip Bone Ilium Pubis Ischium Next Back Appendicular Skeleton: Pelvic Girdle The sacrum and coccyx are part of the axial skeleton not appendicular skeleton. Appendicular Skeleton: Pelvic Girdle Coxal Bone Structure Appendicular Skeleton: Pelvic Girdle Male and Female Pelvis Comparison Femur Bone Proximal End Head and Neck Trochanter (Greater & Lesser) Intertrochanteric Line & Crest Shaft or Body 3 Borders: Lateral, Medial & Posterior (Linea Aspera) 3 Surfaces: Anterior, Lateral & Medial Distal End 2 Condyle: Lateral & Medial 1 Notch: Intercondylar Notch 1 Surface: Patellar Appendicular Skeleton: Femoral Region The thigh has one bone Femur – thigh bone Proximal End Proximal End Back Shaft or Body Back Distal End Review Next Appendicular Skeleton: Patellar and Crural Regions The leg has two bones Tibia Fibula Appendicular Skeleton: Tarsal, Pes, and Digits Regions The foot Tarsus – ankle Metatarsals – sole Phalanges – toes Articulations: Joints • A joint is a location where two or more bones meet. • Functions of joints • Hold bones together • Allow for mobility • Ways joints are classified • Functionally • Structurally Types of Joints • Fibrous joints • Generally immovable (sutures of skull) • Cartilaginous joints • Immovable or slightly moveable (vertebral disc) • Synovial joints • Freely moveable (shoulder, pelvis, knee, elbow, digits) • Articulating bones are separated by a joint cavity • Synovial fluid is found in the joint cavity Structure of a Synovial Joint Figure 5.28 Type of Synovial Joints Types of Synovial Joints perpendicular plate of ethmoid Med part of labyrinth Appendicular Skeleton: Brachium Region The arm is formed by a single bone Humerus Appendicular Skeleton: Antebrachium Region • The forearm has two bones • Ulna (side adjacent to little finger) • Radius (side adjacent to thumb) Appendicular Skeleton: Carpus, Manus, and Digits Region The hand Carpals – wrist Metacarpals – palm Phalanges – fingers