© 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 watch?v=8d-RBe8JBVs

© 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 1. Compact bone 2. Spongy bone Small needle-like pieces of bone Many open spaces

© 2012 Pearson Education, Inc. Classification of Bones on the Basis of Shape Bones are classified as: Long Short Flat Irregular

© 2012 Pearson Education, Inc. 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 bones) Example: Femur Humerus

© 2012 Pearson Education, Inc. 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. 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. Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Example: Vertebrae Hip bones

© 2012 Pearson Education, Inc. Anatomy of a Long Bone Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone Figure 5.3a Distal epiphysis Diaphysis Proximal epiphysis Articular cartilage Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined by endosteum) (a) om/watch?v=owlpf6z Hgyw

© 2012 Pearson Education, Inc. 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 elmfu elmfu

© 2012 Pearson Education, Inc. Figure 5.3c Yellow bone marrow Compact bone Perforating (Sharpey’s) fibers Nutrient arteries Periosteum Endosteum (c)

© 2012 Pearson Education, Inc. Figure 5.3b Compact bone Spongy bone Articular cartilage (b) Anatomy of a Long Bone Articular cartilage Covers the external surface of the epiphyses Made of cartilage Decreases friction at joint surfaces

© 2012 Pearson Education, Inc. Figure 5.3a Distal epiphysis Diaphysis Proximal epiphysis Articular cartilage Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined by endosteum) (a) Epiphyseal plate Flat plate of hyaline cartilage seen in young, growing bone Epiphyseal line Remnant of the epiphyseal plate Seen in adult bones Anatomy of a Long Bone

© 2012 Pearson Education, Inc. 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. 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. Figure 5.4a Compact bone Periosteal blood vessel Periosteum Perforating fibers Central (Haversian) canal Perforating (Volkmann’s) canal Blood vessel Spongy bone Blood vessel continues into medullary cavity containing marrow Lamellae (a) Osteon (Haversian system)

© 2012 Pearson Education, Inc. 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 d8&feature=relmfu d8&feature=relmfu

© 2012 Pearson Education, Inc. Figure 5.4b Lamella Canaliculus Lacuna Central (Haversian) canal (b) Osteocyte

© 2012 Pearson Education, Inc. Figure 5.4c Osteon Lacuna Central canal Interstitial lamellae (c)

© 2012 Pearson Education, Inc. 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 dZI&feature=relmfu dZI&feature=relmfu

© 2012 Pearson Education, Inc. Figure 5.4b Lamella Canaliculus Lacuna Central (Haversian) canal (b) Osteocyte utube.com/wat ch?v=ylmanE GjRuY&featur e=relmfu

© 2012 Pearson Education, Inc. Formation of the Human Skeleton In embryos, the skeleton is primarily hyaline cartilage During development, much of this cartilage is replaced by bone – called ossification 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. Figure 5.5 In a fetus In an embryo Bone collar Hyaline cartilage model Bone starting to replace cartilage In a child Medullary cavity New center of bone growth Hyaline cartilage Epiphyseal plate cartilage Growth in bone length New bone forming Invading blood vessels Epiphyseal plate cartilage Articular cartilage Spongy bone New bone forming Growth in bone width m/watch?v=t5_3sNLtfx Q

© 2012 Pearson Education, Inc. 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 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 ch?v=c5Q5GPwAS4k Setting a bone: UQkU&feature=related UQkU&feature=related

© 2012 Pearson Education, Inc. Comminuted fracture Compression fracture

© 2012 Pearson Education, Inc. Depressed fracture Impacted fracture

© 2012 Pearson Education, Inc. Spiral fracture Greenstick fracture

© 2012 Pearson Education, Inc. Logan’s leg – spiral, comminuted (he had fragments) & impacted

© 2012 Pearson Education, Inc. Figure 5.7 Internal callus (fibrous tissue and cartilage) Hematoma forms. Fibrocartilage callus forms. Bony callus forms. Bone remodeling occurs Hematoma Bony callus of spongy bone Spongy bone trabecula New blood vessels External callus Healed fracture Healing of bone fractures

© 2012 Pearson Education, Inc. Joints Articulations of bones Functions of joints Hold bones together Allow for mobility Two ways joints are classified Functionally Structurally

© 2012 Pearson Education, Inc. 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. Figure 5.31 Acromion of scapula Ligament Bursa Ligament Tendon sheath Tendon of biceps muscle Humerus Fibrous layer of the articular capsule Synovial membrane Articular (hyaline) cartilage Joint cavity containing synovial fluid

© 2012 Pearson Education, Inc. Figure 5.32a Nonaxial Uniaxial Biaxial Multiaxial (a) Plane joint (a) Flat articular surfaces, slipping or gliding movements, intercarpal joints of wrist is best example

© 2012 Pearson Education, Inc. Figure 5.32b Nonaxial Uniaxial Biaxial Multiaxial (b) Humerus Ulna (b) Hinge joint One cylindrical surface & one trough-shaped surface, angular movement in one plane, elbow, ankle, phalanges

© 2012 Pearson Education, Inc. Figure 5.32c Nonaxial Uniaxial Biaxial Multiaxial (c) (c) Pivot joint Ulna Radius Rounded end of one bone fits into a sleeve or ring of another, pivoting movement, proximal radioulnar joint

© 2012 Pearson Education, Inc. Figure 5.32e Nonaxial Uniaxial Biaxial Multiaxial (e) Carpal (e) Saddle joint Metacarpal #1 Saddle like surfaces that fit together, side to side & back & forth movements, carpometacarpal joints of thumb (twiddle thumbs to see movements)

© 2012 Pearson Education, Inc. Figure 5.32f Nonaxial Uniaxial Biaxial Multiaxial (f) Head of humerus Scapula (f) Ball-and-socket joint One spherical head fits into round socket of other, rotational movement (multiaxial), intercarpal joints of shoulder & hip

© 2012 Pearson Education, Inc. Knee Replacement Basic knee anatomy Knee replacement surgery explained with diagram Knee replacement surgery video - graphic but wonderfully explained & only 10 minutes. Let kids who don't want to see this go to either another room or to the lab area of the room.

© 2012 Pearson Education, Inc. Skeletal System Disorders & Diseases Osteoarthritis – disease of the aged; degeneration of articular cartilage Bursitis – inflammation of bursae Rickets – disease of children in which bones fail to calcify; caused by vitamin D deficiency (needed to absorb Ca from intestines into blood) Osteoporosis - the creation of new bone doesn't keep up with the removal of old bone. Most common in post menopausal white & Asian women.

© 2012 Pearson Education, Inc. Osteoarthritis

© 2012 Pearson Education, Inc. Bursitis

© 2012 Pearson Education, Inc. Rickets

© 2012 Pearson Education, Inc. Osteoporosis

© 2012 Pearson Education, Inc. Importance of appropriate dietary Ca & strength of bones when young: Your bones are in a constant state of renewal — new bone is made and old bone is broken down. When you're young, your body makes new bone faster than it breaks down old bone and your bone mass increases. Most people reach their peak bone mass by their early 20s. As people age, bone mass is lost faster than it's created. How likely you are to develop osteoporosis depends partly on how much bone mass you attained in your youth. The higher your peak bone mass, the more bone you have "in the bank" and the less likely you are to develop osteoporosis as you age.

© 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. Figure 5.34 Frontal bone of skull Mandible Radius Ulna Humerus Femur Tibia Hip bone Vertebra Ribs Scapula Clavicle Occipital bone Parietal bone

© 2012 Pearson Education, Inc. Figure 5.35a

© 2012 Pearson Education, Inc. Figure 5.35b

© 2012 Pearson Education, Inc. The Axial Skeleton Forms the longitudinal axis of the body Divided into three parts Skull Vertebral column Bony thorax

© 2012 Pearson Education, Inc. Figure 5.8a (a) Anterior view Phalanges Metatarsals Tarsals Fibula Tibia Patella Femur Metacarpals Phalanges Carpals Ulna Radius Vertebra Humerus Rib Sternum Scapula Clavicle Facial bones Cranium Skull Thoracic cage (ribs and sternum) Vertebral column Sacrum

© 2012 Pearson Education, Inc. Figure 5.8a (a) Anterior view Phalanges Metatarsals Tarsals Fibula Tibia Patella Femur Metacarpals Phalanges Carpals Ulna Radius Vertebra Humerus Rib Sternum Scapula Clavicle Facial bones Cranium Skull Thoracic cage (ribs and sternum) Vertebral column Sacrum Composed of 126 bones Limbs (appendages) Pectoral girdle Pelvic girdle The Appendicular Skeleton

© 2012 Pearson Education, Inc. Figure 5.8b (b) Posterior view Fibula Tibia Femur Metacarpals Phalanges Carpals Radius Ulna Vertebra Humerus Rib Scapula Clavicle Cranium Bones of pectoral girdle Upper limb Bones of pelvic girdle Lower limb

© 2012 Pearson Education, Inc. Figure 5.8a (a) Anterior view Phalanges Metatarsals Tarsals Fibula Tibia Patella Femur Metacarpals Phalanges Carpals Ulna Radius Vertebra Humerus Rib Sternum Scapula Clavicle Facial bones Cranium Skull Thoracic cage (ribs and sternum) Vertebral column Sacrum

© 2012 Pearson Education, Inc. Figure 5.8a (a) Anterior view Phalanges Metatarsals Tarsals Fibula Tibia Patella Femur Metacarpals Phalanges Carpals Ulna Radius Vertebra Humerus Rib Sternum Scapula Clavicle Facial bones Cranium Skull Thoracic cage (ribs and sternum) Vertebral column Sacrum Composed of 126 bones Limbs (appendages) Pectoral girdle Pelvic girdle The Appendicular Skeleton

© 2012 Pearson Education, Inc. 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. Figure 5.9 Coronal suture Parietal bone Lambdoid suture Temporal bone Squamous suture Occipital bone Zygomatic process External acoustic meatus Mastoid process Styloid process Mandibular ramus Frontal bone Sphenoid bone Ethmoid bone Lacrimal bone Nasal bone Zygomatic bone Maxilla Alveolar processes Mandible (body) Mental foramen

© 2012 Pearson Education, Inc. Figure 5.10 Sphenoid bone Temporal bone Internal acoustic meatus Parietal bone Occipital bone Foramen magnum Jugular foramen Foramen ovale Sella turcica Optic canal Frontal bone Cribriform plate Crista galli Ethmoid bone

© 2012 Pearson Education, Inc. Figure 5.11 Maxilla (palatine process) Hard palate Palatine bone Zygomatic bone Temporal bone (zygomatic process) Vomer Mandibular fossa Styloid process Mastoid process Temporal bone Parietal bone Occipital bone Foramen magnum Occipital condyle Jugular foramen Carotid canal Foramen ovale Sphenoid bone (greater wing) Maxilla

© 2012 Pearson Education, Inc. Figure 5.12 Coronal suture Parietal bone Nasal bone Sphenoid bone Ethmoid bone Lacrimal bone Zygomatic bone Maxilla Mandible Alveolar processes Vomer Inferior nasal concha Middle nasal concha of ethmoid bone Temporal bone Optic canal Superior orbital fissure Frontal bone

© 2012 Pearson Education, Inc. Skull Links to videos & practice Calvaria bones explained Facial bones exlained p p Interactive Practice kull_lateral_7_m.html kull_lateral_7_m.html Interactive Practice: roll-over

© 2012 Pearson Education, Inc. 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. Figure 5.15a Frontal bone Parietal bone (a) Occipital bone Anterior fontanel Posterior fontanel

© 2012 Pearson Education, Inc. Figure 5.15b Anterior fontanel Frontal bone Sphenoidal fontanel Parietal bone Posterior fontanel Occipital bone Mastoid fontanel Temporal bone (b)

© 2012 Pearson Education, Inc. -oo V9a9Ota8 Craniosynostosis Explanation video & Jack’s story

© 2012 Pearson Education, Inc.