5 The Skeletal System PowerPoint
PowerPoint® Lecture Slides Prepared by Patty Bostwick-Taylor, Florence-Darlington Technical College CHAPTER 5 The Skeletal System © 2012 Pearson Education, Inc. The Skeletal System •Parts of the skeletal system •Bones (skeleton) •Joints •Cartilages •Ligaments •Two subdivisions of the skeleton •Axial skeleton •Appendicular skeleton © 2012 Pearson Education, Inc. Functions of Bones • Support the body • Protect soft organs • Skull and vertebrae for brain and spinal cord • Rib cage for thoracic cavity organs • Allow movement due to attached skeletal muscles • Store minerals and fats • Calcium and phosphorus • Fat in the internal marrow cavity • Blood cell formation (hematopoiesis) © 2012 Pearson Education, Inc. Bones of the Human Body •The adult skeleton has 206 bones •Two basic types of bone tissue •Compact bone •Homogeneous •Spongy bone •Small needle-like pieces of bone •Many open spaces © 2012 Pearson Education, Inc. Spongy bone Compact bone © 2012 Pearson Education, Inc. Figure 5.1 Classification of Bones on the Basis of Shape •Bones are classified as: •Long •Short •Flat •Irregular © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.2 Classification of Bones •Long bones • Typically longer than they are wide • Shaft with heads situated at both ends • Contain mostly compact bone • All of the bones of the limbs (except wrist, ankle, and kneecap bones) • Example: • Femur • Humerus © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.2a Classification of Bones •Short bones •Generally cube-shaped •Contain mostly spongy bone •Includes bones of the wrist and ankle •Sesamoid bones are a type of short bone which form within tendons (patella) •Example: •Carpals •Tarsals © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.2d Classification of Bones •Flat bones •Thin, flattened, and usually curved •Two thin layers of compact bone surround a layer of spongy bone •Example: •Skull •Ribs •Sternum © 2012 Pearson Education, Inc. Spongy bone Compact bone © 2012 Pearson Education, Inc. Figure 5.1 © 2012 Pearson Education, Inc. Figure 5.2c Classification of Bones •Irregular bones •Irregular shape •Do not fit into other bone classification categories •Example: •Vertebrae •Hip bones © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.2b Anatomy of a Long Bone •Diaphysis •Shaft •Composed of compact bone •Epiphysis •Ends of the bone •Composed mostly of spongy bone © 2012 Pearson Education, Inc. Articular cartilage Proximal epiphysis Diaphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined by endosteum) Distal epiphysis (a) © 2012 Pearson Education, Inc. Figure 5.3a Anatomy of a Long Bone •Periosteum •Outside covering of the diaphysis •Fibrous connective tissue membrane •Perforating (Sharpey’s) fibers •Secure periosteum to underlying bone •Arteries •Supply bone cells with nutrients © 2012 Pearson Education, Inc. Endosteum Yellow bone marrow Compact bone Periosteum Perforating (Sharpey’s) fibers Nutrient arteries (c) © 2012 Pearson Education, Inc. Figure 5.3c Anatomy of a Long Bone •Articular cartilage •Covers the external surface of the epiphyses •Made of hyaline cartilage •Decreases friction at joint surfaces © 2012 Pearson Education, Inc. Articular cartilage Compact bone Spongy bone (b) © 2012 Pearson Education, Inc. Figure 5.3b Anatomy of a Long Bone •Epiphyseal plate •Flat plate of hyaline cartilage seen in young, growing bone •Epiphyseal line •Remnant of the epiphyseal plate •Seen in adult bones © 2012 Pearson Education, Inc. Articular cartilage Proximal epiphysis Diaphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined by endosteum) Distal epiphysis (a) © 2012 Pearson Education, Inc. Figure 5.3a Anatomy of a Long Bone •Marrow (medullary) cavity •Cavity inside of the shaft •Contains yellow marrow (mostly fat) in adults •Contains red marrow for blood cell formation in infants •In adults, red marrow is situated in cavities of spongy bone and epiphyses of some long bones © 2012 Pearson Education, Inc. Articular cartilage Proximal epiphysis Diaphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined by endosteum) Distal epiphysis (a) © 2012 Pearson Education, Inc. Figure 5.3a Bone Markings • Surface features of bones • Sites of attachments for muscles, tendons, and ligaments • Passages for nerves and blood vessels • Categories of bone markings • Projections or processes—grow out from the bone surface • Terms often begin with “T” • Depressions or cavities—indentations • Terms often begin with “F” © 2012 Pearson Education, Inc. Microscopic Anatomy of Compact Bone •Osteon (Haversian system) •A unit of bone containing central canal and matrix rings •Central (Haversian) canal •Opening in the center of an osteon •Carries blood vessels and nerves •Perforating (Volkmann’s) canal •Canal perpendicular to the central canal •Carries blood vessels and nerves © 2012 Pearson Education, Inc. Osteon (Haversian system) Lamellae Blood vessel continues into medullary cavity containing marrow Spongy bone Perforating fibers Compact bone Periosteal blood vessel Periosteum (a) © 2012 Pearson Education, Inc. Central (Haversian) canal Perforating (Volkmann’s) canal Blood vessel Figure 5.4a Microscopic Anatomy of Bone •Lacunae •Cavities containing bone cells (osteocytes) •Arranged in concentric rings called lamellae •Lamellae •Rings around the central canal •Sites of lacunae © 2012 Pearson Education, Inc. Lamella Osteocyte (b) © 2012 Pearson Education, Inc. Canaliculus Lacuna Central (Haversian) canal Figure 5.4b Osteon Lacuna © 2012 Pearson Education, Inc. (c) Central canal Interstitial lamellae Figure 5.4c Microscopic Anatomy of Bone •Canaliculi •Tiny canals •Radiate from the central canal to lacunae •Form a transport system connecting all bone cells to a nutrient supply © 2012 Pearson Education, Inc. Lamella Osteocyte (b) © 2012 Pearson Education, Inc. Canaliculus Lacuna Central (Haversian) canal Figure 5.4b Formation of the Human Skeleton •In embryos, the skeleton is primarily hyaline cartilage •During development, much of this cartilage is replaced by bone •Cartilage remains in isolated areas •Bridge of the nose •Parts of ribs •Joints © 2012 Pearson Education, Inc. Bone Growth (Ossification) •Epiphyseal plates allow for lengthwise growth of long bones during childhood •New cartilage is continuously formed •Older cartilage becomes ossified •Cartilage is broken down •Enclosed cartilage is digested away, opening up a medullary cavity •Bone replaces cartilage through the action of osteoblasts © 2012 Pearson Education, Inc. Bone Growth (Ossification) •Bones are remodeled and lengthened until growth stops •Bones are remodeled in response to two factors •Blood calcium levels •Pull of gravity and muscles on the skeleton •Bones grow in width (called appositional growth) © 2012 Pearson Education, Inc. Articular cartilage Hyaline cartilage Spongy bone New center of bone growth New bone forming Epiphyseal plate cartilage Growth in bone width Medullary cavity Bone starting to replace cartilage Growth in bone length New bone forming Bone collar Hyaline cartilage model In an embryo © 2012 Pearson Education, Inc. Invading blood vessels Epiphyseal plate cartilage In a fetus In a child Figure 5.5 Bone starting to replace cartilage Bone collar Hyaline cartilage model In an embryo © 2012 Pearson Education, Inc. Figure 5.5, step 1 Hyaline cartilage New center of bone growth Medullary cavity Invading Growth blood in bone vessels length In a fetus © 2012 Pearson Education, Inc. Figure 5.5, step 2 Articular cartilage Spongy bone New bone forming Epiphyseal plate cartilage Growth in bone width Invading blood vessels New bone forming Epiphyseal plate cartilage In a child © 2012 Pearson Education, Inc. Figure 5.5, step 3 Bone growth Bone grows in length because: 1 Cartilage grows here. 2 Cartilage is replaced by bone here. 3 Cartilage grows here. 4 Cartilage is replaced by bone here. © 2012 Pearson Education, Inc. Bone remodeling Growing shaft is remodeled as: Articular cartilage Epiphyseal plate 1 Bone is resorbed here. 2 Bone is added by appositional growth here. 3 Bone is resorbed here. Figure 5.6 Types of Bone Cells •Osteocytes—mature bone cells •Osteoblasts—bone-forming cells •Osteoclasts—giant bone-destroying cells •Break down bone matrix for remodeling and release of calcium in response to parathyroid hormone •Bone remodeling is performed by both osteoblasts and osteoclasts © 2012 Pearson Education, Inc. Bone Fractures •Fracture—break in a bone •Types of bone fractures •Closed (simple) fracture—break that does not penetrate the skin •Open (compound) fracture—broken bone penetrates through the skin •Bone fractures are treated by reduction and immobilization © 2012 Pearson Education, Inc. Common Types of Fractures •Comminuted—bone breaks into many fragments •Compression—bone is crushed •Depressed—broken bone portion is pressed inward •Impacted—broken bone ends are forced into each other •Spiral—ragged break occurs when excessive twisting forces are applied to a bone •Greenstick—bone breaks incompletely © 2012 Pearson Education, Inc. Repair of Bone Fractures •Hematoma (blood-filled swelling) is formed •Break is splinted by fibrocartilage to form a callus •Fibrocartilage callus is replaced by a bony callus •Bony callus is remodeled to form a permanent patch © 2012 Pearson Education, Inc. Hematoma External callus New blood vessels Internal callus (fibrous tissue and cartilage) 1 Hematoma forms. © 2012 Pearson Education, Inc. Bony callus of spongy bone Healed fracture Spongy bone trabecula 2 Fibrocartilage callus forms. 3 Bony callus forms. 4 Bone remodeling occurs. Figure 5.7 Hematoma 1 Hematoma forms. © 2012 Pearson Education, Inc. Figure 5.7, step 1 Hematoma External callus New blood vessels Internal callus (fibrous tissue and cartilage) 1 Hematoma forms. © 2012 Pearson Education, Inc. Spongy bone trabecula 2 Fibrocartilage callus forms. Figure 5.7, step 2 Hematoma External callus New blood vessels Internal callus (fibrous tissue and cartilage) 1 Hematoma forms. © 2012 Pearson Education, Inc. Bony callus of spongy bone Spongy bone trabecula 2 Fibrocartilage callus forms. 3 Bony callus forms. Figure 5.7, step 3 Hematoma External callus New blood vessels Internal callus (fibrous tissue and cartilage) 1 Hematoma forms. © 2012 Pearson Education, Inc. Bony callus of spongy bone Healed fracture Spongy bone trabecula 2 Fibrocartilage callus forms. 3 Bony callus forms. 4 Bone remodeling occurs. Figure 5.7, step 4 The Axial Skeleton •Forms the longitudinal axis of the body •Divided into three parts •Skull •Vertebral column •Bony thorax © 2012 Pearson Education, Inc. Cranium Skull Facial bones Clavicle Thoracic cage (ribs and sternum) Scapula Sternum Rib Humerus Vertebral column Vertebra Radius Ulna Sacrum Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges (a) Anterior view © 2012 Pearson Education, Inc. Figure 5.8a Cranium Bones of pectoral girdle Clavicle Scapula Upper limb Rib Humerus Vertebra Radius Ulna Carpals Bones of pelvic girdle Phalanges Metacarpals Femur Lower limb Tibia Fibula (b) Posterior view © 2012 Pearson Education, Inc. Figure 5.8b The Skull •Two sets of bones •Cranium •Facial bones •Bones are joined by sutures •Only the mandible is attached by a freely movable joint © 2012 Pearson Education, Inc. Coronal suture Frontal bone Parietal bone Sphenoid bone Temporal bone Ethmoid bone Lambdoid suture Lacrimal bone Squamous suture Nasal bone Occipital bone Zygomatic bone Zygomatic process Maxilla External acoustic meatus Mastoid process Styloid process Mandibular ramus © 2012 Pearson Education, Inc. Alveolar processes Mandible (body) Mental foramen Figure 5.9 Frontal bone Sphenoid bone Cribriform plate Crista galli Ethmoid bone Optic canal Sella turcica Foramen ovale Temporal bone Jugular foramen Internal acoustic meatus Parietal bone Occipital bone Foramen magnum © 2012 Pearson Education, Inc. Figure 5.10 Hard palate Maxilla (palatine process) Palatine bone Zygomatic bone Temporal bone (zygomatic process) Maxilla Sphenoid bone (greater wing) Foramen ovale Vomer Mandibular fossa Carotid canal Styloid process Mastoid process Temporal bone Jugular foramen Occipital condyle Parietal bone Foramen magnum Occipital bone © 2012 Pearson Education, Inc. Figure 5.11 Coronal suture Frontal bone Parietal bone Nasal bone Superior orbital fissure Sphenoid bone Ethmoid bone Lacrimal bone Optic canal Temporal bone Zygomatic bone Middle nasal concha of ethmoid bone Maxilla Inferior nasal concha Vomer Mandible Alveolar processes © 2012 Pearson Education, Inc. Figure 5.12 Paranasal Sinuses •Hollow portions of bones surrounding the nasal cavity •Functions of paranasal sinuses •Lighten the skull •Give resonance and amplification to voice © 2012 Pearson Education, Inc. Frontal sinus Ethmoid sinus Sphenoidal sinus Maxillary sinus (a) Anterior view © 2012 Pearson Education, Inc. Figure 5.13a Frontal sinus Ethmoid sinus Sphenoidal sinus Maxillary sinus (b) Medial view © 2012 Pearson Education, Inc. Figure 5.13b The Hyoid Bone •The only bone that does not articulate with another bone •Serves as a moveable base for the tongue •Aids in swallowing and speech © 2012 Pearson Education, Inc. Greater horn Lesser horn Body © 2012 Pearson Education, Inc. Figure 5.14 The Fetal Skull •The fetal skull is large compared to the infant’s total body length •Fetal skull is 1/4 body length compared to adult skull which is 1/8 body length •Fontanels—fibrous membranes connecting the cranial bones •Allow skull compression during birth •Allow the brain to grow during later pregnancy and infancy •Convert to bone within 24 months after birth © 2012 Pearson Education, Inc. Frontal bone Anterior fontanel Parietal bone Posterior fontanel Occipital bone (a) © 2012 Pearson Education, Inc. Figure 5.15a Parietal bone Posterior fontanel Occipital bone Mastoid fontanel Anterior fontanel Sphenoidal fontanel Frontal bone Temporal bone (b) © 2012 Pearson Education, Inc. Figure 5.15b The Vertebral Column •Each vertebrae is given a name according to its location •There are 24 single vertebral bones separated by intervertebral discs •Seven cervical vertebrae are in the neck •Twelve thoracic vertebrae are in the chest region •Five lumbar vertebrae are associated with the lower back © 2012 Pearson Education, Inc. The Vertebral Column •Nine vertebrae fuse to form two composite bones •Sacrum •Coccyx © 2012 Pearson Education, Inc. Anterior 1st cervical vertebra (atlas) 2nd cervical vertebra (axis) 1st thoracic vertebra Transverse process Spinous process Intervertebral disc Posterior Cervical curvature (concave) 7 vertebrae, C1 – C7 Thoracic curvature (convex) 12 vertebrae, T1 – T12 Intervertebral foramen 1st lumbar vertebra Lumbar curvature (concave) 5 vertebrae, L1 – L5 Sacral curvature (convex) 5 fused vertebrae Coccyx 4 fused vertebrae © 2012 Pearson Education, Inc. Figure 5.16 The Vertebral Column •Primary curvatures are the spinal curvatures of the thoracic and sacral regions •Present from birth •Form a C-shaped curvature as in newborns •Secondary curvatures are the spinal curvatures of the cervical and lumbar regions •Develop after birth •Form an S-shaped curvature as in adults © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.17 © 2012 Pearson Education, Inc. Figure 5.18 A Typical Vertebrae •Body •Vertebral arch •Pedicle •Lamina •Vertebral foramen •Transverse processes •Spinous process •Superior and inferior articular processes © 2012 Pearson Education, Inc. Posterior Vertebral arch Lamina Transverse process Spinous process Superior articular process and facet Pedicle Vertebral foramen Body © 2012 Pearson Education, Inc. Anterior Figure 5.19 (a) ATLAS AND AXIS Transverse process Posterior arch Anterior arch Superior view of atlas (C1) Transverse process Dens Body Spinous process Facet on superior articular process Superior view of axis (C2) © 2012 Pearson Education, Inc. Figure 5.20a (b) TYPICAL CERVICAL VERTEBRAE Facet on superior articular process Spinous process Vertebral foramen Transverse process Superior view Superior articular process Spinous process © 2012 Pearson Education, Inc. Body Transverse process Facet on inferior articular process Right lateral view Figure 5.20b (c) THORACIC VERTEBRAE Spinous process Transverse process Vertebral foramen Facet for rib Facet on superior articular process Body Superior view Facet on superior articular process Facet on transverse process Body Spinous process Costal facet for rib Right lateral view © 2012 Pearson Education, Inc. Figure 5.20c (d) LUMBAR VERTEBRAE Spinous process Vertebral foramen Transverse process Facet on superior articular process Body Superior view Superior articular process Spinous process © 2012 Pearson Education, Inc. Body Facet on inferior articular process Right lateral view Figure 5.20d Sacrum and Coccyx •Sacrum •Formed by the fusion of five vertebrae •Coccyx •Formed from the fusion of three to five vertebrae •“Tailbone,” or remnant of a tail that other vertebrates have © 2012 Pearson Education, Inc. Ala Sacral canal Superior Auricular articular surface process Body Sacrum Coccyx © 2012 Pearson Education, Inc. Median sacral crest Posterior sacral foramina Sacral hiatus Figure 5.21 The Bony Thorax •Forms a cage to protect major organs •Consists of three parts •Sternum •Ribs •True ribs (pairs 1–7) •False ribs (pairs 8–12) •Floating ribs (pairs 11–12) •Thoracic vertebrae © 2012 Pearson Education, Inc. T1 vertebra Jugular notch Clavicular notch Manubrium Sternal angle Body Xiphisternal joint Xiphoid process True ribs (1 –7) Sternum False ribs (8–12) L1 Vertebra (a) © 2012 Pearson Education, Inc. Floating ribs (11, 12) Intercostal spaces Costal cartilage Figure 5.22a T2 T3 T4 Jugular notch Sternal angle Heart T9 Xiphisternal joint (b) © 2012 Pearson Education, Inc. Figure 5.22b The Appendicular Skeleton •Composed of 126 bones •Limbs (appendages) •Pectoral girdle •Pelvic girdle © 2012 Pearson Education, Inc. Cranium Skull Facial bones Clavicle Thoracic cage (ribs and sternum) Scapula Sternum Rib Humerus Vertebral column Vertebra Radius Ulna Sacrum Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges (a) Anterior view © 2012 Pearson Education, Inc. Figure 5.8a Cranium Bones of pectoral girdle Clavicle Scapula Upper limb Rib Humerus Vertebra Radius Ulna Carpals Bones of pelvic girdle Phalanges Metacarpals Femur Lower limb Tibia Fibula (b) Posterior view © 2012 Pearson Education, Inc. Figure 5.8b The Pectoral (Shoulder) Girdle •Composed of two bones •Clavicle—collarbone •Articulates with the sternum medially and with the scapula laterally •Scapula—shoulder blade •Articulates with the clavicle at the acromioclavicular joint •Articulates with the arm bone at the glenoid cavity •These bones allow the upper limb to have exceptionally free movement © 2012 Pearson Education, Inc. Acromioclavicular Clavicle joint Scapula © 2012 Pearson Education, Inc. (a) Articulated right shoulder (pectoral) girdle showing the relationship to bones of the thorax and sternum Figure 5.23a Posterior Sternal (medial) end Acromial (lateral) end Anterior Superior view Acromial end Sternal end Anterior Posterior Inferior view (b) Right clavicle, superior and inferior views © 2012 Pearson Education, Inc. Figure 5.23b Suprascapular notch Coracoid process Superior angle Acromion Glenoid cavity at lateral angle Spine Medial border Lateral border (c) Right scapula, posterior aspect © 2012 Pearson Education, Inc. Figure 5.23c Acromion Coracoid process Suprascapular notch Superior border Superior angle Glenoid cavity Lateral (axillary) border Medial (vertebral) border Inferior angle (d) Right scapula, anterior aspect © 2012 Pearson Education, Inc. Figure 5.23d Bones of the Upper Limbs •Humerus •Forms the arm •Single bone •Proximal end articulation •Head articulates with the glenoid cavity of the scapula •Distal end articulation •Trochlea and capitulum articulate with the bones of the forearm © 2012 Pearson Education, Inc. Greater tubercle Lesser tubercle Head of humerus Anatomical neck Intertubercular sulcus Deltoid tuberosity Radial fossa Coronoid fossa © 2012 Pearson Education, Inc. Capitulum (a) Medial epicondyle Trochlea Figure 5.24a Head of humerus Anatomical neck Surgical neck Radial groove Deltoid tuberosity © 2012 Pearson Education, Inc. Medial epicondyle Olecranon fossa Trochlea Lateral epicondyle (b) Figure 5.24b Bones of the Upper Limbs •The forearm has two bones •Ulna—medial bone in anatomical position •Proximal end articulation • Coronoid process and olecranon articulate with the humerus •Radius—lateral bone in anatomical position •Proximal end articulation • Head articulates with the capitulum of the humerus © 2012 Pearson Education, Inc. Trochlear notch Olecranon Head Neck Radial tuberosity Coronoid process Proximal radioulnar joint Radius Ulna Interosseous membrane Ulnar styloid process Radial styloid process (c) © 2012 Pearson Education, Inc. Distal radioulnar joint Figure 5.24c Bones of the Upper Limbs •Hand •Carpals—wrist •Eight bones arranged in two rows of four bones in each hand •Metacarpals—palm •Five per hand •Phalanges—fingers and thumb •Fourteen phalanges in each hand •In each finger, there are three bones •In the thumb, there are only two bones © 2012 Pearson Education, Inc. Distal Phalanges (fingers) Middle Proximal Metacarpals (palm) 4 3 2 5 1 Trapezium Hamate Trapezoid Carpals Pisiform (wrist) Triquetrum Scaphoid Capitate Lunate Ulna © 2012 Pearson Education, Inc. Radius Figure 5.25 Bones of the Pelvic Girdle •Formed by two coxal (ossa coxae) bones •Composed of three pairs of fused bones •Ilium •Ischium •Pubis •Pelvic girdle = 2 coxal bones, sacrum •Bony pelvis = 2 coxal bones, sacrum, coccyx © 2012 Pearson Education, Inc. Bones of the Pelvic Girdle •The total weight of the upper body rests on the pelvis •It protects several organs •Reproductive organs •Urinary bladder •Part of the large intestine © 2012 Pearson Education, Inc. lliac crest Sacroiliac joint llium Coxal bone (or hip bone) Sacrum Pubis Pelvic brim Coccyx Ischial spine Acetabulum Pubic symphysis Ischium Pubic arch (a) © 2012 Pearson Education, Inc. Figure 5.26a IIium Ala IIiac crest Posterior superior iliac spine Anterior superior iliac spine Posterior inferior iliac spine Anterior inferior iliac spine Greater sciatic notch Acetabulum Ischial body Body of pubis Ischial spine Pubis Ischial tuberosity Ischium Ischial ramus (b) © 2012 Pearson Education, Inc. Inferior pubic ramus Obturator foramen Figure 5.26b Gender Differences of the Pelvis •The female inlet is larger and more circular •The female pelvis as a whole is shallower, and the bones are lighter and thinner •The female ilia flare more laterally •The female sacrum is shorter and less curved •The female ischial spines are shorter and farther apart; thus the outlet is larger •The female pubic arch is more rounded because the angle of the pubic arch is greater © 2012 Pearson Education, Inc. False pelvis Inlet of true pelvis Pelvic brim Pubic arch (less than 90°) False pelvis Inlet of true pelvis Pelvic brim Pubic arch (more than 90°) (c) © 2012 Pearson Education, Inc. Figure 5.26c Bones of the Lower Limbs •Femur—thigh bone •The heaviest, strongest bone in the body •Proximal end articulation •Head articulates with the acetabulum of the coxal (hip) bone •Distal end articulation •Lateral and medial condyles articulate with the tibia in the lower leg © 2012 Pearson Education, Inc. Neck Head Intertrochanteric line Lesser trochanter Lateral condyle Patellar surface (a) © 2012 Pearson Education, Inc. Figure 5.27a Head Lesser trochanter Gluteal tuberosity Intercondylar fossa Medial condyle © 2012 Pearson Education, Inc. (b) Greater trochanter Intertrochanteric crest Lateral condyle Figure 5.27b Bones of the Lower Limbs •The lower leg has two bones •Tibia—Shinbone; larger and medially oriented •Proximal end articulation • Medial and lateral condyles articulate with the femur to form the knee joint •Fibula—Thin and sticklike; lateral to the tibia •Has no role in forming the knee joint © 2012 Pearson Education, Inc. Intercondylar eminence Medial condyle Tibial tuberosity Lateral condyle Head Proximal tibiofibular joint Interosseous membrane Anterior border Fibula Tibia Distal tibiofibular joint Medial malleolus Lateral malleolus © 2012 Pearson Education, Inc. (c) Figure 5.27c Bones of the Lower Limbs •The foot •Tarsals—seven bones •Two largest tarsals • Calcaneus (heel bone) • Talus •Metatarsals—five bones form the sole of the foot •Phalanges—fourteen bones form the toes © 2012 Pearson Education, Inc. Phalanges: Distal Middle Proximal Tarsals: Medial cuneiform Intermediate cuneiform Navicular Metatarsals Tarsals: Lateral cuneiform Cuboid Talus Calcaneus © 2012 Pearson Education, Inc. Figure 5.28 Arches of the Foot •Bones of the foot are arranged to form three strong arches •Two longitudinal •One transverse © 2012 Pearson Education, Inc. Medial longitudinal arch Transverse arch Lateral longitudinal arch © 2012 Pearson Education, Inc. Figure 5.29 Joints •Articulations of bones •Functions of joints •Hold bones together •Allow for mobility •Two ways joints are classified •Functionally •Structurally © 2012 Pearson Education, Inc. Functional Classification of Joints •Synarthroses •Immovable joints •Amphiarthroses •Slightly moveable joints •Diarthroses •Freely moveable joints © 2012 Pearson Education, Inc. Structural Classification of Joints •Fibrous joints •Generally immovable •Cartilaginous joints •Immovable or slightly moveable •Synovial joints •Freely moveable © 2012 Pearson Education, Inc. Fibrous Joints •Bones united by collagenic fibers •Types • Sutures • Immobile • Syndesmoses • Allows more movement than sutures but still immobile • Example: Distal end of tibia and fibula • Gomphosis • Immobile © 2012 Pearson Education, Inc. Fibrous joints Fibrous connective tissue (a) Suture © 2012 Pearson Education, Inc. Figure 5.30a Fibrous joints Tibia Fibula Fibrous connective tissue (b) Syndesmosis © 2012 Pearson Education, Inc. Figure 5.30b Cartilaginous Joints •Bones connected by cartilage •Types •Synchrondrosis •Immobile •Symphysis •Slightly movable •Example: Pubic symphysis, intervertebral joints © 2012 Pearson Education, Inc. Cartilaginous joints First rib Hyaline cartilage Sternum (c) Synchondrosis © 2012 Pearson Education, Inc. Figure 5.30c Cartilaginous joints Vertebrae Fibrocartilage (d) Symphysis © 2012 Pearson Education, Inc. Figure 5.30d Cartilaginous joints Pubis Fibrocartilage (e) Symphysis © 2012 Pearson Education, Inc. Figure 5.30e Synovial Joints •Articulating bones are separated by a joint cavity •Synovial fluid is found in the joint cavity © 2012 Pearson Education, Inc. Synovial joints Scapula Articular capsule Articular (hyaline) cartilage Humerus (f) Multiaxial joint (shoulder joint) © 2012 Pearson Education, Inc. Figure 5.30f Synovial joints Humerus Articular (hyaline) cartilage Articular capsule Radius (g) Uniaxial joint (elbow joint) © 2012 Pearson Education, Inc. Ulna Figure 5.30g Synovial joints Ulna Radius Carpals Articular capsule (h) Biaxial joint (intercarpal joints of hand) © 2012 Pearson Education, Inc. Figure 5.30h Features of Synovial Joints •Articular cartilage (hyaline cartilage) covers the ends of bones •Articular capsule encloses joint surfaces and lined with synovial membrane •Joint cavity is filled with synovial fluid •Reinforcing ligaments © 2012 Pearson Education, Inc. Structures Associated with the Synovial Joint •Bursae—flattened fibrous sacs •Lined with synovial membranes •Filled with synovial fluid •Not actually part of the joint •Tendon sheath •Elongated bursa that wraps around a tendon © 2012 Pearson Education, Inc. Acromion of scapula Ligament Joint cavity containing synovial fluid Bursa Ligament Articular (hyaline) cartilage Tendon sheath Synovial membrane Fibrous layer of the articular capsule Tendon of biceps muscle Humerus © 2012 Pearson Education, Inc. Figure 5.31 Nonaxial Uniaxial Biaxial Multiaxial (a) Plane joint (a) © 2012 Pearson Education, Inc. Figure 5.32a Nonaxial Uniaxial Biaxial Multiaxial (b) Humerus Ulna (b) Hinge joint © 2012 Pearson Education, Inc. Figure 5.32b Nonaxial Uniaxial Biaxial Multiaxial Ulna Radius (c) (c) Pivot joint © 2012 Pearson Education, Inc. Figure 5.32c Nonaxial Uniaxial Biaxial Multiaxial (d) Metacarpal Phalanx (d) Condylar joint © 2012 Pearson Education, Inc. Figure 5.32d Nonaxial Uniaxial Biaxial Multiaxial Carpal Metacarpal #1 (e) (e) Saddle joint © 2012 Pearson Education, Inc. Figure 5.32e Nonaxial Uniaxial Biaxial Multiaxial (f) Head of humerus Scapula (f) Ball-and-socket joint © 2012 Pearson Education, Inc. Figure 5.32f Inflammatory Conditions Associated with Joints •Bursitis—inflammation of a bursa usually caused by a blow or friction •Tendonitis—inflammation of tendon sheaths •Arthritis—inflammatory or degenerative diseases of joints •Over 100 different types •The most widespread crippling disease in the United States •Initial symptoms: pain, stiffness, swelling of the joint © 2012 Pearson Education, Inc. Clinical Forms of Arthritis •Osteoarthritis •Most common chronic arthritis •Probably related to normal aging processes •Rheumatoid arthritis •An autoimmune disease—the immune system attacks the joints •Symptoms begin with bilateral inflammation of certain joints •Often leads to deformities © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.33 Clinical Forms of Arthritis •Gouty arthritis •Inflammation of joints is caused by a deposition of uric acid crystals from the blood •Can usually be controlled with diet •More common in men © 2012 Pearson Education, Inc. Developmental Aspects of the Skeletal System •At birth, the skull bones are incomplete •Bones are joined by fibrous membranes called fontanels •Fontanels are completely replaced with bone within two years after birth © 2012 Pearson Education, Inc. Parietal bone Frontal bone of skull Mandible Occipital bone Clavicle Scapula Radius Ulna Humerus Femur Tibia Ribs Vertebra Hip bone © 2012 Pearson Education, Inc. Figure 5.34 Skeletal Changes Throughout Life •Fetus •Long bones are formed of hyaline cartilage •Flat bones begin as fibrous membranes •Flat and long bone models are converted to bone •Birth •Fontanels remain until around age 2 © 2012 Pearson Education, Inc. Skeletal Changes Throughout Life •Adolescence •Epiphyseal plates become ossified and long bone growth ends •Size of cranium in relationship to body •2 years old—skull is larger in proportion to the body compared to that of an adult •8 or 9 years old—skull is near adult size and proportion •Between ages 6 and 11, the face grows out from the skull © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.35a © 2012 Pearson Education, Inc. Figure 5.35b Skeletal Changes Throughout Life •Curvatures of the spine •Primary curvatures are present at birth and are convex posteriorly •Secondary curvatures are associated with a child’s later development and are convex anteriorly •Abnormal spinal curvatures (scoliosis and lordosis) are often congenital © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.18 Skeletal Changes Throughout Life •Osteoporosis •Bone-thinning disease afflicting •50 percent of women over age 65 •20 percent of men over age 70 •Disease makes bones fragile and bones can easily fracture •Vertebral collapse results in kyphosis (also known as dowager’s hump) •Estrogen aids in health and normal density of a female skeleton © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 5.36 © 2012 Pearson Education, Inc. Figure 5.37
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