Essentials of Anatomy & Physiology, 4th Edition Martini / Bartholomew 6 The Skeletal System PowerPoint Lecture Outlines prepared by Alan Magid, Duke University Slides 1 to 137
The Skeletal System The skeletal system includes: Bones Cartilages Joints Ligaments
The Skeletal System Functions of the Skeletal System 1. Support; framework for attachment of soft tissues 2. Storage Calcium, phosphorous Fat 3. Blood cell production 4. Protection of soft internal organs 5. Leverage for muscle action
The Structure of Bone Bone (Osseous Tissue) has 2 parts: 1. Specialized cells 2% of bone weight 2. Strong flexible matrix Calcium phosphate crystals Two-thirds of bone weight Collagen fibers One-third of bone weight
The Structure of Bone Macroscopic Features of Bone General shapes of bones 1. Long bones (e.g., humerus) 2. Short bones (e.g., carpal bones) 3. Flat bones (e.g., parietal bone in the skull) 4. Irregular bones (e.g., vertebra)
The Structure of Bone Shapes of Bones Figure 6-1
The Structure of Bone Features in a Long Bone 1. Diaphysis (shaft) Compact (dense) bone Marrow cavity (yellow marrow) 2. Epiphyses (ends) Spongy bone Red marrow 3. Articular cartilage 4. Periosteum (covering) 5. Endosteum (lining)
The Structure of Bone The Structure of a Long Bone Figure 6-2
The Structure of Bone Microscopic Features of Compact Bone 1. Periosteum Outer fibrous layer Inner cellular layer 2. Osteocytes (bone cells) Within lacunae (holes) in matrix Between lamellae of matrix Branches within canaliculi
The Structure of Bone Microscopic Features of Bone 3. Osteon Basic functional unit of compact bone; columnar in shape Concentric layers of osteocytes Concentric layers of matrix (lamellae) Central (Haversian) canal Tunnel for blood vessels Perforating canal Radial tunnel for blood vessels
The Structure of Bone Structure of a Typical Bone Figure 6-3(a)
The Structure of Bone Structure of a Typical Bone Figure 6-3(b)
The Structure of Bone Microscopic Features of Spongy Bone No osteons Trabeculae Arches, rods, plates of bone Branching network of bony tissue Red marrow (blood forming) spaces
The Structure of Bone Cells in Bone 1. Osteocytes Mature bone cells between lamellae 2. Osteoclasts Source of acid, enzymes for osteolysis Calcium homeostasis 3. Osteoblasts Responsible for osteogenesis (new bone) Source of collagen, calcium salts
Bone Formation and Growth Two types of bone growth & formation: 1. Intramembranous Ossification Ossification Process of converting other tissues to bone Forms flat bones of skull, mandible, clavicle Stem cells differentiate to osteoblasts Produces spongy bone, then compact bone
Bone Formation and Growth Bone Formation in 16-Week-Old Fetus Figure 6-4
Bone Formation and Growth 2. Endochondral Ossification Most bones formed this way Cartilage model replaced by bone Replacement begins in middle (diaphysis) Replacement follows in ends (epiphyses)
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone. Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center. The bone of the shaft thickens, and the cartilage near each epiphysis is replaced by shafts of bone. Blood vessels invade the epiphyses and osteoblasts form secondary centers of ossification. Articular cartilage Enlarging chondrocytes within calcifying matrix Epiphysis Diaphysis Marrow cavity Marrow cavity Epiphyseal cartilage Bone formation Primary ossification center Blood vessel Blood vessel Secondary ossification center Cartilage model Figure 6-5 1 of 6
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Enlarging chondrocytes within calcifying matrix Cartilage model Figure 6-5 2 of 6
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone. Enlarging chondrocytes within calcifying matrix Epiphysis Diaphysis Bone formation Cartilage model Figure 6-5 3 of 6
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Enlarging chondrocytes within calcifying matrix Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone. Epiphysis Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center. Diaphysis Marrow cavity Cartilage model Bone formation Primary ossification center Blood vessel Figure 6-5 4 of 6
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone. Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center. The bone of the shaft thickens, and the cartilage near each epiphysis is replaced by shafts of bone. Enlarging chondrocytes within calcifying matrix Epiphysis Diaphysis Marrow cavity Marrow cavity Bone formation Primary ossification center Blood vessel Blood vessel Cartilage model Figure 6-5 5 of 6
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calicifies. Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone. Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center. The bone of the shaft thickens, and the cartilage near each epiphysis is replaced by shafts of bone. Blood vessels invade the epiphyses and osteoblasts form secondary centers of ossification. Articular cartilage Enlarging chondrocytes within calcifying matrix Epiphysis Diaphysis Marrow cavity Marrow cavity Epiphyseal cartilage Bone formation Primary ossification center Blood vessel Blood vessel Secondary ossification center Cartilage model PLAY Endochondral Ossification Figure 6-5 6 of 6
Bone Formation and Growth Appositional Bone Growth Figure 6-6
Bone Formation and Growth Requirements for Normal Bone Growth 1. Minerals Calcium, phosphate 2. Vitamins Vitamin D 3 required for calcium metabolism Vitamin C Vitamin A 3. Hormones Growth Hormone Sex hormones, thyroid hormone, others
Bone Remodeling/Homeostasis Role of Remodeling in Support 1. Remodeling Continuous breakdown and reforming of bone tissue 2. Shapes reflect applied loads 3. Mineral turnover enables adapting to new stresses; heavily stressed bones become thicker and stronger, bones not subjected to normal stress become thin & brittle.
Bone Remodeling/Homeostasis Key Note What you don t use, you lose. The stresses applied to bones during exercise are essential to maintaining bone strength and bone mass
Bone Remodeling/Homeostasis Homeostasis and Mineral Storage 1. Bones store calcium Contain 99% of body calcium Store up to two kg calcium Hormones control storage/release PTH, calcitriol release bone calcium Calcitonin stores bone calcium Blood levels of calcium kept constant
Bone Remodeling/Homeostasis Injury and Repair 1. Fracture A crack or break in a bone 2. Steps in fracture repair Fracture hematoma (blood clot) Mitosis in periosteum, endosteum Internal callus External callus Bone remodeling
Immediately after the fracture, extensive bleeding occurs. Over a period of several hours, a large blood clot, or fracture hematoma, develops. Bone fragments An internal callus forms as a network of spongy bone unites the inner edges, and an external callus of cartilage and bone stabilizes the outer edges. Spongy bone of internal callus Cartilage of external callus The cartilage of the external callus has been replaced by bone, and struts of spongy bone now unite the broken ends. Fragments of dead bone and the areas of bone closest to the break have been removed and replaced. A swelling initially marks the location of the fracture. Over time, this region will be remodeled, and little evidence of the fracture will remain. Fracture hematoma External callus Dead bone New bone Periosteum Internal callus External callus Figure 6-7 1 of 5
Immediately after the fracture, extensive bleeding occurs. Over a period of several hours, a large blood clot, or fracture hematoma, develops. Bone fragments Fracture hematoma Dead bone Figure 6-7 2 of 5
Immediately after the fracture, extensive bleeding occurs. Over a period of several hours, a large blood clot, or fracture hematoma, develops. An internal callus forms as a network of spongy bone unites the inner edges, and an external callus of cartilage and bone stabilizes the outer edges. Bone fragments Spongy bone of internal callus Cartilage of external callus Fracture hematoma Dead bone New bone Periosteum Figure 6-7 3 of 5
Immediately after the fracture, extensive bleeding occurs. Over a period of several hours, a large blood clot, or fracture hematoma, develops. Bone fragments An internal callus forms as a network of spongy bone unites the inner edges, and an external callus of cartilage and bone stabilizes the outer edges. Spongy bone of internal callus Cartilage of external callus The cartilage of the external callus has been replaced by bone, and struts of spongy bone now unite the broken ends. Fragments of dead bone and the areas of bone closest to the break have been removed and replaced. Fracture hematoma Dead bone New bone Periosteum Internal callus External callus Figure 6-7 4 of 5
Immediately after the fracture, extensive bleeding occurs. Over a period of several hours, a large blood clot, or fracture hematoma, develops. Bone fragments An internal callus forms as a network of spongy bone unites the inner edges, and an external callus of cartilage and bone stabilizes the outer edges. Spongy bone of internal callus Cartilage of external callus The cartilage of the external callus has been replaced by bone, and struts of spongy bone now unite the broken ends. Fragments of dead bone and the areas of bone closest to the break have been removed and replaced. A swelling initially marks the location of the fracture. Over time, this region will be remodeled, and little evidence of the fracture will remain. Fracture hematoma External callus Dead bone New bone Periosteum Internal callus External callus PLAY Steps in the Repair of a Fracture Figure 6-7 5 of 5
Aging and the Skeletal System Osteopenia Less than normal ossification (mineral content) in bone Osteopenia starts before age 40 Women lose 8% per decade Men lose 3% per decade Spongy bone most affected Epiphyses Vertebrae Jaws
An Overview of the Skeleton Bone Markings (Selected) Process Head Neck Fossa Condyle Sulcus Foramen Fissure Sinus
An Overview of the Skeleton Surface Features of Bones Table 6-1 (1 of 2)
An Overview of the Skeleton Surface Features of Bones Table 6-1 (2 of 2)
An Overview of the Skeleton Skeletal Divisions 1. Axial skeleton Skull ribs and sternum Vertebral column 2. Appendicular skeleton Upper, lower limbs Pectoral girdle Pelvic girdle
An Overview of the Skeleton The Skeleton Figure 6-8(a)
An Overview of the Skeleton The Skeleton Figure 6-8(b)
An Overview of the Skeleton The Axial and Appendicular Divisions of the Skeleton. p. 147 Figure 6-9
The Axial Division: The Skull Bones of the Cranium 1. Frontal bone Forehead, superior surface of orbits 2. Parietal bones Sides, roof 3. Occipital bone Foramen magnum - opening through which spinal cord enters skull 4. Temporal bones Sides, base
The Axial Division: The Skull Bones of the Cranium (continued) 5. Sphenoid bone Bridge between cranial and facial bones 6. Ethmoid bone Forms roof and side of nasal cavity Nasal septum
Sutures Sutures: joints between cranial bones 1. Sagittal suture 2. Coronal suture 3. Lambdoid suture 4. Squamous suture
The Axial Division: The Skull The Adult Skull (Part I) Figure 6-10
The Axial Division: The Skull Bones of the Face 1. Maxillary bones -walls of nasal cavities and hard palate 2. Zygomatic bones Form the zygomatic arch (with temporal bones) or cheekbone 3. Mandible Lower jaw bone
The Axial Division: The Skull Bones of the Face (continued) 4. Palatine bones (hard palate) 5. The Vomer (nasal septum) 6. Nasal bones (bridge of nose) 7. Lacrimal bones 8. Inferior nasal conchae 9. Nasal complex Nasal septum Contain paranasal sinuses
The Axial Division: The Skull Bones of the Face (continued) Paranasal sinuses Frontal Sphenoidal Ethmoidal Palatine Maxillary
The Axial Division: The Skull The Adult Skull (Part II) Figure 6-11(a)
The Axial Division: The Skull The Adult Skull (Part II) Figure 6-11(b)
The Axial Division: The Skull Sectional Anatomy of the Skull Figure 6-12(a)
The Axial Division: The Skull Sectional Anatomy of the Skull Figure 6-12(b)
The Axial Division: The Skull Sectional Anatomy of the Skull Figure 6-12(c)
The Axial Division: The Skull The Paranasal Sinuses Figure 6-13
The Axial Division: The Skull The Hyoid Bone Point of attachment for larynx, tongue and pharynx Figure 6-14
Axial Division: The Skull The Skull of a Newborn Figure 6-15(a)
Axial Division: The Skull The Skull of a Newborn Fontanel: soft spot Flexible Connective tissue Permits distortion of skull w/o damage Figure 6-15(b)
Vertebral Column/Thoracic Cage Vertebral Column (Spine) 26 Bones 7 Cervical vertebrae (C 1 to C 7 ) 12 Thoracic vertebrae (T 1 to T 12 ) 5 Lumbar vertebrae (L 1 to L 5 ) Sacrum Coccyx (tailbone)
Vertebral Column/Thoracic Cage Spinal Curvature Alignment of body weight Primary curves (convex) Thoracic Sacral Secondary curves (concave) Cervical Lumbar
Vertebral Column/Thoracic Cage The Vertebral Column Figure 6-16
Vertebral Column/Thoracic Cage Vertebral Anatomy Body Arch Transverse, spinous processes Pedicle, lamina Vertebral foramen Vertebral canal Articular processes Articular facets Intervertebral discs
Vertebral Column/Thoracic Cage Regional Differences in Vertebrae Cervical Oval body Transverse foramina Thoracic Heart-shaped body Lumbar Massive (heaviest loading) Blade-like transverse processes
Vertebral Column/Thoracic Cage Typical Vertebrae of the Cervical, Thoracic, and Lumbar Regions Figure 6-17(a)
Vertebral Column/Thoracic Cage Typical Vertebrae of the Cervical, Thoracic, and Lumbar Regions Figure 6-17(b)
Vertebral Column/Thoracic Cage Typical Vertebrae of the Cervical, Thoracic, and Lumbar Regions Figure 6-17(c)
Vertebral Column/Thoracic Cage The Atlas and Axis Figure 6-18
Vertebral Column/Thoracic Cage Functions of Sacrum Protects pelvic organs Base articulates with lumbar vertebra Apex articulates with coccyx
Vertebral Column/Thoracic Cage The Sacrum and Coccyx Figure 6-19(a)
Vertebral Column/Thoracic Cage The Sacrum and Coccyx Figure 6-19(b)
Vertebral Column/Thoracic Cage Components of Thoracic Cage 1. Thoracic vertebrae 2. Ribs Seven pairs of true ribs Cartilaginous joint with sternum Five pairs of false ribs (aka 3 pr of false and 2 pair of floating ) 3. Sternum Manubrium, body, xiphoid process
Vertebral Column/Thoracic Cage The Thoracic Cage Figure 6-20(a)
Vertebral Column/Thoracic Cage The Thoracic Cage Figure 6-20(b)
Appendicular Division Pectoral Girdle (Shoulder Girdle) Components Scapulae ( shoulder blade ) Clavicles ( collar bone ) Functions Shoulder, arm movement Articulation for arm
Appendicular Division The Clavicle Figure 6-21
Appendicular Division The Scapula Figure 6-22
Appendicular Division Upper Limb 1. Humerus Head articulates with scapula Muscles attach to Greater, lesser tubercles Deltoid tuberosity Medial, lateral epicondyles Distal condyle articulates with forearm
Appendicular Division Upper Limb Anatomy Distal articulation of humerus Coronoid fossa Olecranon fossa Trochlea
Appendicular Division The Humerus Figure 6-23
Appendicular Division Bones of the Forearm 1. Radius Lateral (thumb side) Head articulates with humerus Radial tuberosity attaches biceps brachii Participates in wrist joint 2. Ulna Trochlear notch articulates with humerus Olecranon forms point of elbow
Appendicular Division The Radius and Ulna Figure 6-24
Appendicular Division Bones of the Wrist and Hand Two rows of carpal bones (wrist) -- 8 total Proximal articulation with radius Distal articulation with metacarpal bones (palm of hand) Proximal phalanges (finger bones) articulate with metacarpals Three phalanges/finger Two phalanges/thumb
Appendicular Division Bones of the Wrist and Hand Figure 6-25
Appendicular Division The Pelvic Girdle Formed by two coxae (hipbones) Coxa formed by fusion of: Ilium Ischium Pubis Pubic symphysis limit movement Pelvis formed by coxae, sacrum, coccyx
Appendicular Division The Pelvis Figure 6-26(a)
Appendicular Division The Pelvis Figure 6-26(b)
Appendicular Division The Pelvis Figure 6-26(c)
Appendicular Division Differences in the Anatomy of the Pelvis in Males and Females PLAY Male and Female Pelvis Figure 6-27
Appendicular Division Bones of the Lower Limb Femur (thighbone) Patella (kneecap) Tibia (shinbone) Fibula Ankle bones Foot bones
Appendicular Division 1. The Femur Bone of the thigh Longest bone in body Articulates proximally with hip and distally with tibia Figure 6-28
Appendicular Division Bones of the Lower Limb (cont.) 2. Features of the tibia Tibial tuberosity Patellar tendon attachment AKA shin bone 3. Features of the fibula Articulation of head with tibia
Appendicular Division The Right Tibia and Fibula Figure 6-29
Appendicular Division The Bones of the Ankle and Foot 1. Ankle Seven tarsal bones Talus -- largest tarsal Joint with tibia, fibula 2. Foot Calcaneus (heel bone) Major load-bearing bone Metatarsal bones Five phalanges (toes)
Appendicular Division The Bones of the Ankle and Foot Figure 6-30(a)
Appendicular Division The Bones of the Ankle and Foot Figure 6-30(b)
Articulations Classification of Joints (Articulations) Joint Where two bones interact Three functional classes of joint 1. Synarthroses Immovable 2. Amphiarthroses Slightly movable 3. Diarthroses Freely movable
Articulations Examples of Joints Synarthroses Suture Amphiarthroses Symphysis Diarthroses Synovial joints -- knee, shoulder, etc
Articulations Synovial Joints (Diarthroses) Epiphyses covered by articular cartilage Lubricated by synovial fluid Enclosed within joint capsule Other synovial structures include: Menisci Bursae Fat pads Ligaments
Articulations The Structure of Synovial Joints Figure 6-31(a)
Articulations The Structure of Synovial Joints Figure 6-31(b)
Articulations Synovial Joints: Movements Flexion Extension Hyperextension Abduction Adduction Circumduction Rotation Pronation, supination
Articulations Angular Movements Figure 6-32(a)
Articulations Angular Movements Figure 6-32(b)
Articulations Angular Movements Figure 6-32(c)
Articulations Angular Movements PLAY Angular Movements Figure 6-32(d)
Articulations Rotational Movements Figure 6-33(a)
Articulations Rotational Movements Figure 6-33(b)
Articulations Special Movements Foot and ankle Inversion, eversion Dorsiflexion, plantar flexion Hand Opposition of thumb, palm Head Protraction, retraction Depression, elevation (jaw)
Articulations Special Movements Figure 6-34
Articulations Structural Classification of Synovial Joints 1. Gliding (e.g., vertebra vertebra) 2. Hinge (e.g., knee) 3. Pivot (e.g., atlas axis) 4. Ellipsoidal (e.g., distal radius) 5. Saddle (e.g., thumb) 6. Ball-and-Socket (e.g., hip)
Articulations Structural Classification of Synovial Joints Figure 6-35(a)
Articulations Structural Classification of Synovial Joints Figure 6-35(b)
Articulations Structural Classification of Synovial Joints Figure 6-35(c)
Articulations Structural Classification of Synovial Joints Figure 6-35(d)
Articulations Structural Classification of Synovial Joints Figure 6-35(e)
Articulations Structural Classification of Synovial Joints PLAY A Functional Classification of Synovial Joints Figure 6-35(f)
Articulations Key Note A joint cannot be both highly mobile and very strong. The greater the mobility, the weaker the joint, because mobile joints rely on support from muscles and ligaments rather than solid bone-tobone connections.
Articulations Intervertebral Articulations Two kinds join adjacent vertebrae 1. Gliding joints Between superior and inferior articular processes Permit small movements 2. Symphyseal joints Intervertebral discs composed of fibrocartilage Cushion and connect
Articulations Intervertebral Articulations Figure 6-36
Articulations The Shoulder Joint Ball-and-socket design frees movement Humerus head mates with glenoid cavity Joint capsule extends from scapular neck to humerus Joint dislocates easily Bursae reduce friction Bursitis restricts motion, causes pain
Articulations The Shoulder Joint PLAY Humerus Rotation Figure 6-37
Articulations The Elbow Joint Two articulations 1. Humerus radius 2. Humerus ulna Interlocking hinge design Limited movement Flexion and extension only Strong ligaments
Articulations The Elbow Joint PLAY Elbow Flexion/Extension Figure 6-38
Articulations The Hip Joint Acetabulum and head of femur Ball and socket Extremely strong, stable joint Many strong ligaments Tough joint capsule Bulky muscles Versatile movements Flexion, extension, adduction, abduction, circumduction, rotation
Articulations The Hip Joint Figure 6-39
Articulations The Knee Joint Complex hinge joint Three separate articulations 1 & 2. Femur-tibia (between condyles lateral and medial) 3. Femur-patella Fibrocartilage pads Medial and lateral menisci Ligaments Cruciate ligaments inside joint
Articulations The Knee Joint Figure 6-40
The Skeletal System in Perspective FIGURE 6-41 Functional Relationships Between the Skeletal System and Other Systems Figure 6-41 1 of 11
The Integumentary System Synthesizes vitamin D 3, essential for calcium and phosphorus absorption (bone maintenance and growth) Provides structural support Figure 6-41 2 of 11
The Muscular System Stabilizes bone positions; tension in tendons stimulates bone growth and maintenance Provides calcium needed for normal muscle contraction; bones act as levers to produce body movements Figure 6-41 3 of 11
The Nervous System Regulates bone position by controlling muscle contractions Provides calcium for neural function; protects brain, spinal cord; receptors at joints provide information about body position Figure 6-41 4 of 11
The Endocrine System Skeletal growth regulated by growth hormone, thyroid hormones, and sex hormones; calcium mobilization regulated by parathyroid hormone and calcitonin Protects endocrine organs, especially in brain, chest, and pelvic cavity Figure 6-41 5 of 11
The Cardiovascular System Provides oxygen, nutrients, hormones, blood cells; removes waste products and carbon dioxide Provides calcium needed for cardiac muscle contraction, blood cells produced in bone marrow Figure 6-41 6 of 11
The Lymphatic System Lymphocytes assist in the defense and repair of bone following injuries Lymphocytes and other cells of the immune response are produced and stored in bone marrow Figure 6-41 7 of 11
The Respiratory System Provides oxygen and eliminates carbon dioxide Movements of ribs important in breathing; axial skeleton surrounds and protects lungs Figure 6-41 8 of 11
The Digestive System Provides nutrients, calcium, and phosphate Ribs protect portions of liver, stomach, and intestines Figure 6-41 9 of 11
The Urinary System Conserves calcium and phosphate needed for bone growth; disposes of waste products Axial skeleton provides some protection for kidneys and ureters; pelvis protects urinary bladder and proximal urethra Figure 6-41 10 of 11
The Reproductive System Sex hormones stimulate growth and maintenance of bones; surge of sex hormones at puberty causes acceleration of growth and closure of epiphyseal cartilages Pelvis protects reproductive organs of female, protects portion of ductus deferens and accessory glands in males Figure 6-41 11 of 11