Skeletal System CH5 PDF

07/10/2023 Chapter 5 The Skeletal System SKELETAL SYSTEM...

07/10/2023 Chapter 5 The Skeletal System SKELETAL SYSTEM ▪ Parts of the skeletal system ▪ Bones (skeleton) ▪ Joints ▪ Cartilages ▪ Ligaments ▪ Two subdivisions of the skeleton 1. Axial skeleton 2. Appendicular skeleton © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 1 2 © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 3 4 Functions of the Bones Classification of Bones ▪ Support the body ▪ The adult skeleton has 206 bones ▪ Protect soft organs ▪ Two basic types of osseous (bone) tissue ▪ Skull and vertebrae protect brain and spinal cord 1. Compact bone ▪ Rib cage protects thoracic cavity organs ▪ Dense, smooth, and homogeneous ▪ Attached skeletal muscles allow movement 2. Spongy bone ▪ Small needlelike pieces of bone ▪ Store minerals and fats ▪ Many open spaces ▪ Calcium and phosphorus ▪ Fat in the internal marrow cavity ▪ Blood cell formation (hematopoiesis) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 5 6 1  07/10/2023 Figure 5.1 Flat bones consist of a layer of spongy bone sandwiched between two thin layers of compact bone. Classification of Bone ▪ Bones are classified on the basis of shape into four groups ▪ Long ▪ Flat ▪ Short ▪ Irregular Spongy bone Compact bone © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 7 8 Figure 5.2 Classification of bones on the basis of shape. Classification of Bones ▪ Long bones ▪ Typically longer than they are wide ▪ Shaft with enlarged ends (b) Flat bone (sternum) ▪ Contain mostly compact bone; spongy bone at ends (a) Long bone (humerus) ▪ All of the bones of the limbs (except wrist, ankle, and kneecap bones) are long bones ▪ Examples: ▪ Femur ▪ Humerus (d) Irregular bone (vertebra), right lateral view (c) Short bone (talus) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 9 10 Figure 5.2a Classification of bones on the basis of shape. Classification of Bones ▪ Flat bones ▪ Thin, flattened, and usually curved ▪ Two thin layers of compact bone sandwich a layer of spongy bone between them (a) Long bone (humerus) ▪ Examples: ▪ Most bones of the skull ▪ Ribs ▪ Sternum © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 11 12 2  07/10/2023 Figure 5.2b Classification of bones on the basis of shape. Classification of Bones ▪ Short bones ▪ Generally cube-shaped ▪ Contain mostly spongy bone with an outer layer of (b) Flat bone (sternum) compact bone ▪ Sesamoid bones are a type of short bone that form within tendons (patella) ▪ Examples: ▪ Carpals (wrist bones) ▪ Tarsals (ankle bones) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 13 14 Figure 5.2c Classification of bones on the basis of shape. Classification of Bones ▪ Irregular bones ▪ Irregular shape ▪ Do not fit into other bone classification categories ▪ Examples: ▪ Vertebrae ▪ Facial bone (c) Short bone (talus) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 15 16 Figure 5.2d Classification of bones on the basis of shape. Structure of Bone ▪ Long bone anatomy ▪ Diaphysis (shaft) ▪ Makes up most of bone’s length ▪ Composed of compact bone ▪ Periosteum ▪ Outside covering of the diaphysis ▪ Fibrous connective tissue membrane ▪ Perforating (Sharpey’s) fibers secure periosteum to underlying bone (d) Irregular bone (vertebra), right lateral view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 17 18 3  07/10/2023 Figure 5.3a The structure of a long bone (humerus of arm). Figure 5.3c The structure of a long bone (humerus of arm). Articular cartilage Endosteum Proximal epiphysis Spongy bone Epiphyseal line Periosteum Yellow bone marrow Compact bone Medullary cavity (lined Compact bone by endosteum) Diaphysis Periosteum Perforating (Sharpey’s) fibers Nutrient arteries Distal epiphysis (a) (c) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 19 20 Figure 5.3b The structure of a long bone (humerus of arm). Structure of Bone Articular cartilage ▪ Long bone anatomy (continued) ▪ Epiphysis (ends) Compact bone ▪ Composed mostly of spongy bone enclosed by thin layer of compact bone Spongy bone ▪ Articular cartilage ▪ Covers the external surface of the epiphyses ▪ Made of hyaline cartilage ▪ Decreases friction at joint surfaces (b) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 21 22 Figure 5.3a The structure of a long bone (humerus of arm). Articular cartilage Structure of Bone Proximal epiphysis ▪ Long bone anatomy (continued) Spongy bone Epiphyseal ▪ Epiphyseal line line Periosteum ▪ Remnant of the epiphyseal plate Compact bone ▪ Seen in adult bones Medullary cavity (lined ▪ Epiphyseal plate by endosteum) Diaphysis ▪ Flat plate of hyaline cartilage seen in young, growing bone ▪ Causes lengthwise growth of a long bone Distal epiphysis (a) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 23 24 4  07/10/2023 Figure 5.3a The structure of a long bone (humerus of arm). Articular cartilage Structure of Bone Proximal epiphysis ▪ Long bone anatomy (continued) Spongy bone Epiphyseal ▪ Endosteum line Periosteum ▪ Lines the inner surface of the shaft Compact bone ▪ Made of connective tissue Medullary cavity (lined ▪ Medullary cavity by endosteum) Diaphysis ▪ Cavity inside the shaft ▪ Contains yellow marrow (mostly fat) in adults ▪ Contains red marrow for blood cell formation in infants until age 6 or 7 Distal epiphysis (a) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 25 26 Table 5.1 Bone Markings (1 of 3) Structure of Bone ▪ Bone markings ▪ 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 ▪ Depressions or cavities—indentations © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 27 28 Table 5.1 Bone Markings (2 of 3) Table 5.1 Bone Markings (3 of 3) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 29 30 5  07/10/2023 Structure of Bone Bone Formation, Growth, and Remodeling ▪ Bone is relatively lightweight and resists tension ▪ Bone formation and growth and other forces ▪ Ossification is the process of bone formation ▪ Organic parts (collagen fibers) of the bone make ▪ Occurs on hyaline cartilage models or fibrous membranes bone flexible and have great tensile strength ▪ Long bone growth involves two major phases ▪ Calcium salts deposited in the bone make bone hard to resist compression © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 31 32 Figure 5.5 Stages of long-bone formation in an embryo, fetus, and young child. Bone Formation, Growth, and Remodeling Articular cartilage Hyaline Spongy ▪ Two major phases of ossification in long bones cartilage bone New center of 1. Osteoblasts (bone-forming cells) cover hyaline bone growth New bone forming cartilage model with bone matrix Epiphyseal plate 2. In a fetus, the enclosed cartilage is digested away, cartilage Growth Medullary in bone opening up a medullary cavity cavity width Bone starting Invading to replace Growth blood cartilage in bone vessels length New bone Bone collar forming Hyaline Epiphyseal cartilage plate cartilage model In an embryo In a fetus In a child © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 33 34 Figure 5.6 Growth and remodeling of long bones. Slide 4 Bone Formation, Growth, and Remodeling Bone growth Bone grows in length because: ▪ By birth, most cartilage is converted to bone except for two regions in a long bone 1 Cartilage Articular cartilage 1. Articular cartilages grows here. Epiphyseal plate 2. Epiphyseal plates 2 Cartilage is replaced by bone here. 3 Cartilage grows here. © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 35 36 6  07/10/2023 Figure 5.6 Growth and remodeling of long bones. Slide 8 Bone Formation, Growth, and Remodeling Bone remodeling Growing shaft is remodeled as: ▪ Appositional growth ▪ Bones grow in width Articular cartilage ▪ Osteoblasts in the periosteum add bone matrix to the Epiphyseal plate outside of the diaphysis 1 Bone is ▪ Osteoclasts in the endosteum remove bone from the resorbed by inner surface of the diaphysis osteoclasts here. 2 Bone is added ▪ Bone growth is controlled by hormones, such as (appositional growth) growth hormone and sex hormones by osteoblasts here. 3 Bone is resorbed by osteoclasts here. © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 37 38 Bone Formation, Growth, and Remodeling Bone Formation, Growth, and Remodeling ▪ Bones are remodeled throughout life in response ▪ Calcium ion regulation to two factors ▪ Parathyroid hormone (PTH) 1. Calcium ion level in the blood determines when bone ▪ Released when calcium ion levels in blood are low matrix is to be broken down or formed ▪ Activates osteoclasts (bone-destroying cells) 2. Pull of gravity and muscles on the skeleton ▪ Osteoclasts break down bone and release calcium ions determines where bone matrix is to be broken down into the blood or formed ▪ Hypercalcemia (high blood calcium levels) prompts calcium storage to bones by osteoblasts © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 39 40 Bone Fractures Bone Fractures ▪ Fracture: break in a bone ▪ Bone fractures are treated by reduction and ▪ Types of bone fractures immobilization ▪ Closed (simple) fracture is a break that does not ▪ Closed reduction: bones are manually coaxed into penetrate the skin position by physician’s hands ▪ Open (compound) fracture is a broken bone that ▪ Open reduction: bones are secured with pins or wires penetrates through the skin during surgery ▪ Healing time is 6–8 weeks © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 41 42 7  07/10/2023 Figure 5.7 Stages in the healing of a bone fracture. Bone Fractures ▪ Repair of bone fractures involves four major events Hematoma ▪ Hematoma (blood-filled swelling, or bruise) is formed External Bony callus callus of spongy ▪ Fibrocartilage callus forms New bone Internal blood ▪ Cartilage matrix, bony matrix, collagen fibers splint the callus vessels Healed fracture (fibrous broken bone tissue and Spongy cartilage) bone ▪ Bony callus replaces the fibrocartilage callus trabecula ▪ Osteoblasts and osteoclasts migrate in 1 Hematoma 2 Fibrocartilage 3 Bony callus 4 Bone remodeling forms. callus forms. forms. occurs. ▪ Bone remodeling occurs in response to mechanical stresses © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 43 44 Table 5.2 Common Types of Fractures © 2018 Pearson Education, Ltd. 45 46 Figure 5.8a The human skeleton. Cranium Axial Skeleton Skull Facial bones Clavicle Thoracic cage Scapula ▪ Forms the longitudinal axis of the body (ribs and sternum) Sternum Rib Humerus ▪ Divided into three parts Vertebral Vertebra Radius column 1. Skull Sacrum Ulna Carpals 2. Vertebral column 3. Bony thorax Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges (a) Anterior view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 47 48 8  07/10/2023 Figure 5.8b The human skeleton. Cranium Bones of Skull pectoral Clavicle girdle Scapula Sternum Rib Upper limb ▪ Two sets of bones form the skull Humerus 1. Cranium bones enclose the brain Vertebra Radius Bones of 2. Facial bones Ulna pelvic Carpals girdle ▪ Hold eyes in anterior position ▪ Allow facial muscles to express feelings Phalanges Metacarpals ▪ Bones are joined by sutures Femur Lower ▪ Only the mandible is attached by a freely Tibia limb movable joint Fibula (b) Posterior view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 49 50 Skull ▪ 8 cranial bones protect the brain 1 Frontal bone 2 Occipital bone 3 Ethmoid bone 4 Sphenoid bone 5, 6 Parietal bones (pair) 7, 8 Temporal bones (pair) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 51 52 Figure 5.9 Human skull, lateral view. Skull Coronal suture Frontal bone Parietal bone ▪ 14 facial bones Sphenoid bone Temporal bone Ethmoid bone 1, 2 Maxillae (pair) Lambdoid Lacrimal bone suture 3, 4 Palatine bones (pair) Squamous suture 5, 6 Lacrimal bones (pair) Occipital bone Nasal bone Zygomatic bone 7, 8 Zygomatic bones (pair) Zygomatic process Maxilla 9, 10 Nasal bones (pair) External acoustic meatus Mastoid process Alveolar processes 11 Vomer bone Styloid process Mandible (body) 12, 13 Inferior nasal conchae (pair) Mental foramen Mandibular ramus 14 Mandible © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 53 54 9  07/10/2023 Figure 5.10 Human skull, superior view (top of cranium removed). Figure 5.11 Human skull, inferior view (mandible removed). Maxilla Frontal bone (palatine process) Incisive fossa Hard palate Cribriform plate Palatine bone Ethmoid Maxilla Crista galli bone Sphenoid bone Optic canal Zygomatic bone Sphenoid bone Temporal bone (greater wing) Sella turcica (zygomatic process) Foramen ovale Foramen ovale Vomer Temporal bone Mandibular fossa Jugular foramen Carotid canal Styloid process Internal acoustic meatus Mastoid process Jugular foramen Parietal bone Temporal bone Occipital condyle Occipital bone Parietal bone Foramen magnum Foramen magnum Occipital bone © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 55 56 Figure 5.12 Human skull, anterior and posterior views. Coronal suture Parietal bone Frontal bone Skull Nasal bone ▪ Paranasal sinuses Superior orbital fissure Sphenoid bone Ethmoid bone Optic canal ▪ Hollow portions of bones surrounding the nasal cavity Temporal bone ▪ Functions of paranasal sinuses Lacrimal bone Zygomatic bone ▪ Lighten the skull Middle nasal concha Infraorbital foramen of ethmoid bone Maxilla Inferior nasal concha Vomer ▪ Amplify sounds made as we speak Mandible Alveolar processes Mental foramen Sagittal suture Anterior view Parietal bone Lambdoid suture Occipital bone Mastoid process of temporal bone Posterior view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 57 58 Figure 5.13a Paranasal sinuses. Figure 5.13b Paranasal sinuses. Frontal sinus Frontal Ethmoid sinus sinus Ethmoid Sphenoidal sinus sinus Sphenoidal Maxillary sinus sinus Maxillary sinus (a) Anterior view (b) Medial view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 59 60 10  07/10/2023 Figure 5.14 Anatomical location and structure of the hyoid bone. Skull ▪ Hyoid bone ▪ Closely related to mandible and temporal bones ▪ The only bone that does not articulate with another bone ▪ Serves as a movable base for the tongue ▪ Aids in swallowing and speech Greater horn Lesser horn Body © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 61 62 Figure 5.15 The vertebral column. Anterior Posterior 1st cervical Vertebral Column (Spine) vertebra (atlas) Cervical curvature 2nd cervical (concave) 7 vertebrae, vertebra (axis) C1 – C 7 ▪ Vertebral column provides axial support 1st thoracic vertebra ▪ Extends from skull to the pelvis Transverse process Spinous Thoracic curvature ▪ 26 vertebral bones are separated by process (convex) 12 vertebrae, T1 – T12 intervertebral discs Intervertebral disc ▪ 7 cervical vertebrae are in the neck Intervertebral foramen ▪ 12 thoracic vertebrae are in the chest region 1st lumbar ▪ 5 lumbar vertebrae are associated with the lower back vertebra Lumbar curvature (concave) 5 vertebrae, ▪ Sacrum (formed by fusion of 5 vertebrae) L1 – L5 ▪ Coccyx (formed by fusion of 3–5 vertebrae) Sacral curvature (convex) 5 fused vertebrae Coccyx 4 fused vertebrae © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 63 64 Figure 5.16 The C-shaped spine typical of a newborn. Vertebral Column (Spine) ▪ Primary curvatures ▪ Spinal curvatures of the thoracic and sacral regions ▪ Present from fetus to birth ▪ Form a C-shaped curvature in newborns ▪ Secondary curvatures ▪ Spinal curvatures of the cervical and lumbar regions ▪ Develop after birth ▪ Form an S-shaped curvature in adults © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 65 66 11  07/10/2023 Figure 5.17 A typical vertebra, superior view. Vertebral Column (Spine) Posterior Lamina Vertebral arch Transverse Spinous process process ▪ Parts of a typical vertebra ▪ Body (centrum) ▪ Vertebral arch ▪ Pedicle Superior ▪ Lamina articular ▪ Vertebral foramen process and ▪ Transverse processes facet ▪ Spinous process Pedicle Vertebral ▪ Superior and inferior articular processes foramen Body Anterior © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 67 68 Figure 5.18a Regional characteristics of vertebrae. Figure 5.18b Regional characteristics of vertebrae. (a) ATLAS AND AXIS (b) TYPICAL CERVICAL VERTEBRAE Facet on superior Spinous Transverse Posterior articular process process process arch Vertebral foramen Anterior Transverse arch process Transverse Superior view of atlas (C1) foramen Superior view Superior Spinous articular Body Transverse process process process Facet on Spinous superior process articular Transverse process process Dens Facet on inferior Body articular process Superior view of axis (C2) Right lateral view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 69 70 Figure 5.18c Regional characteristics of vertebrae. Figure 5.18d Regional characteristics of vertebrae. (c) THORACIC VERTEBRAE (d) LUMBAR VERTEBRAE Spinous process Spinous process Transverse Vertebral process foramen Vertebral foramen Transverse process Facet Facet on for rib superior articular Facet on process superior Body articular Body process Superior view Superior view Facet on Body superior Superior Body articular articular process process Facet on transverse process Costal facet Spinous for rib process Spinous Facet on inferior process articular process Right lateral view Right lateral view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 71 72 12  07/10/2023 Figure 5.19 Sacrum and coccyx, posterior view. Thoracic Cage ▪ Bony thorax, or thoracic cage, protects organs of the thoracic cavity Superior Auricular Ala Sacral canal articular process surface ▪ Consists of three parts 1. Sternum 2. Ribs Body ▪ True ribs (pairs 1–7) Sacrum Median sacral ▪ False ribs (pairs 8–12) crest ▪ Floating ribs (pairs 11–12) Posterior 3. Thoracic vertebrae sacral foramina Sacral Coccyx hiatus © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 73 74 Figure 5.20a The bony thorax (thoracic cage). Figure 5.20b The bony thorax (thoracic cage). T1 vertebra Jugular notch Clavicular notch Manubrium Sternal angle T2 Jugular Body Xiphisternal Sternum T3 notch True joint ribs Xiphoid T4 Sternal (1–7) process angle Heart False T9 Xiphisternal ribs (8–12) joint Intercostal spaces L1 (b) Floating vertebra Costal cartilage ribs (11, 12) (a) © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 75 76 Figure 5.8a The human skeleton. Cranium Appendicular Skeleton Skull Facial bones Clavicle Thoracic cage Scapula ▪ Composed of 126 bones (ribs and sternum) Sternum Rib ▪ Limbs (appendages) Humerus Vertebra Vertebral ▪ Pectoral girdle column Radius Ulna Sacrum ▪ Pelvic girdle Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges (a) Anterior view © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 77 78 13  07/10/2023 Figure 5.8b The human skeleton. Cranium Bones of pectoral Clavicle girdle Scapula Sternum Upper Rib limb Humerus Vertebra Radius Bones of Ulna pelvic Carpals girdle Phalanges Metacarpals Femur Lower Tibia limb Fibula (b) Posterior view © 2018 Pearson Education, Ltd. 79 80 Figure 5.21a Bones of the shoulder girdle. Bones of the Shoulder Girdle Acromio- clavicular Clavicle ▪ Also called pectoral girdle joint ▪ Composed of two bones that attach the upper limb to the axial skeletal 1. Clavicle 2. Scapula ▪ Allows the upper limb an exceptional flexibility Scapula (a) Articulated right shoulder (pectoral) girdle showing the relationship to bones of the thorax and sternum © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd. 81 82 Figure 5.21b Bones of the shoulder girdle. Figure 5.21c Bones of the shoulder girdle. Coracoid process Suprascapular notch Posterior Sternal (medial) Superior Acromion end angle Acromial Glenoid cavity Anterior at lateral angle (lateral) end Spine Superior view Acromial end Sternal end Anterior Medial border Posterior Lateral border Inferior view (b) Right clavicle, superior