Essentials Of Human Anatomy & Physiology Thirteenth Edition Chapter 5 PDF

Essentials of Human Anatomy & Physiology Thirteenth Edition Chapter 5 The Skeletal System Lecture Presentation by Patty Bostw...

Essentials of Human Anatomy & Physiology Thirteenth Edition Chapter 5 The Skeletal System Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Copyright © 2021 Pearson Education, Inc. All Rights Reserved The Skeletal System Parts of the skeletal system – Bones (skeleton) – Joints – Cartilages – Ligaments Two subdivisions of the skeleton 1. Axial skeleton 2. Appendicular skeleton Copyright © 2021 Pearson Education, Inc. All Rights Reserved Functions of the Bones Support the body Protection of soft organs – Skull and vertebrae protect brain and spinal cord – Rib cage protects thoracic cavity organs Allow movement via attached muscles Store minerals and fats – Calcium and phosphorus – Fat in the internal marrow cavity Blood cell formation (hematopoiesis) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (1 of 6) The adult skeleton has 206 bones Two basic types of osseous (bone) tissue 1. Compact bone ▪ Dense, smooth, and homogeneous 2. Spongy bone ▪ Small needlelike pieces of bone ▪ Many open spaces Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.1 Flat Bones Consist of a Layer of Spongy Bone Sandwiched Between Two Thin Layers of Compact Bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (2 of 6) Bones are classified on the basis of shape into four groups – Long – Flat – Short – Irregular Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.2 Classification of Bones on the Basis of Shape Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (3 of 6) Long bones – Typically longer than they are wide – Shaft with enlarged ends – Contain mostly compact bone; spongy bone at ends – All of the bones of the limbs (except wrist, ankle, and kneecap bones) are long bones – Examples: ▪ Femur ▪ Humerus Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.2a Classification of Bones on the Basis of Shape Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (4 of 6) Flat bones – Thin, flattened, and usually curved – Two thin layers of compact bone sandwich a layer of spongy bone between them – Examples: ▪ Most bones of the skull ▪ Ribs ▪ Sternum Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.2b Classification of Bones on the Basis of Shape Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (5 of 6) Short bones – Generally cube-shaped – Contain mostly spongy bone with an outer layer of compact bone – Sesamoid bones are a type of short bone that form within tendons (patella) – Examples: ▪ Carpals (wrist bones) ▪ Tarsals (ankle bones) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.2c Classification of Bones on the Basis of Shape Copyright © 2021 Pearson Education, Inc. All Rights Reserved Classification of Bones (6 of 6) Irregular bones – Irregular shape – Do not fit into other bone classification categories – Examples: ▪ Vertebrae ▪ Hip bones Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.2d Classification of Bones on the Basis of Shape Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (1 of 10) 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 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.3a The Structure of a Long Bone (Humerus of Arm) (1 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.3c The Structure of a Long Bone (Humerus of Arm) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (2 of 10) Long bone anatomy – Epiphysis (ends) ▪ Composed mostly of spongy bone enclosed by thin layer of compact bone – Articular cartilage ▪ Covers the external surface of the epiphyses ▪ Made of hyaline cartilage ▪ Decreases friction at joint surfaces Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.3b The Structure of a Long Bone (Humerus of Arm) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (3 of 10) Long bone anatomy – Epiphyseal line ▪ Remnant of the epiphyseal plate ▪ Seen in adult bones – Epiphyseal plate ▪ Flat plate of hyaline cartilage seen in young, growing bone ▪ Causes lengthwise growth of a long bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.3a The Structure of a Long Bone (Humerus of Arm) (2 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (4 of 10) Long bone anatomy – Endosteum ▪ Lines the inner surface of the shaft ▪ Made of connective tissue – Medullary cavity ▪ Cavity inside the shaft ▪ Contains yellow marrow (mostly fat) in adults ▪ Contains red marrow for blood cell formation until age 6 or 7 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.3a The Structure of a Long Bone (Humerus of Arm) (3 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (6 of 10) Microscopic anatomy of spongy bone – Composed of small, needlelike pieces of bone called trabeculae and open spaces – Open spaces are filled by marrow, blood vessels, and nerves Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.4a Microscopic Structure of Bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (7 of 10) Microscopic anatomy of compact bone – Osteocytes ▪ Mature bone cells situated in bone matrix – Lacunae ▪ Cavities in bone matrix that house osteocytes – Lamellae ▪ Concentric circles of lacunae situated around the central (Haversian) canal Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (8 of 10) Microscopic anatomy of compact bone – Central (Haversian) canal ▪ Opening in the center of an osteon (Haversian system) ▪ Runs lengthwise through bone ▪ Carries blood vessels and nerves – Osteon (Haversian system) ▪ A unit of bone containing central canal and matrix rings ▪ Structural and functional unit of compact bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.4b Microscopic Structure of Bone (1 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.4c Microscopic Structure of Bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (9 of 10) Microscopic anatomy of compact bone – Canaliculi ▪ Tiny canals ▪ Radiate from the central canal to lacunae ▪ Form a transport system connecting all bone cells to a nutrient supply – Perforating (Volkmann’s) canal ▪ Canal perpendicular to the central canal ▪ Carries blood vessels and nerves Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.4b Microscopic Structure of Bone (2 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Structure of Bone (10 of 10) Bone is relatively lightweight and resists tension and other forces Organic parts (collagen fibers) make bone flexible and have great tensile strength (stretch without breaking) Calcium salts deposited in the bone make bone hard (resists compression) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (1 of 6) Bone formation and growth – Ossification is the process of bone formation – Occurs on hyaline cartilage models or fibrous membranes – Long bone growth involves two major phases Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (2 of 6) Two major phases of ossification in long bones 1. In an embryo, osteoblasts (bone-forming cells) cover the hyaline cartilage model with bone matrix 2. In a fetus, the enclosed cartilage is covered by bone; the cartilage is digested away, opening up a medullary cavity Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.5 Stages of Long-Bone Formation in an Embryo, Fetus, and Young Child Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (3 of 6) By birth, most cartilage is converted to bone except for two regions in a long bone 1. Articular cartilages 2. Epiphyseal plates New cartilage is formed continuously on external face of these two cartilages Old cartilage is broken down and replaced by bony matrix Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.6ab Growth and Remodeling of Long Bones Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.6cd Growth and Remodeling of Long Bones Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (4 of 6) Appositional growth – Bones grow in width – Osteoblasts in the periosteum add bone matrix to the outside of the diaphysis – Osteoclasts in the endosteum remove bone from the inner surface of the diaphysis Bone growth is controlled by hormones, such as growth hormone and sex hormones Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (5 of 6) Bones are remodeled throughout life in response to two factors 1. Calcium ion level in the blood determines when bone matrix is to be broken down or formed 2. Pull of gravity and muscles on the skeleton determines where bone matrix is to be broken down or formed Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Formation, Growth, and Remodeling (6 of 6) Calcium ion regulation – Parathyroid hormone (PTH) ▪ Released when calcium ion levels in blood are low ▪ Activates osteoclasts (bone-destroying cells) ▪ Osteoclasts break down bone and release calcium ions into the blood – Hypercalcemia (high blood calcium levels) prompts calcium storage to bones by osteoblasts Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Fractures (1 of 3) Fracture: break in a bone Types of bone fractures – Closed (simple) fracture is a break that does not penetrate the skin – Open (compound) fracture is a broken bone that penetrates through the skin Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Fractures (2 of 3) Bone fractures are treated by reduction and immobilization – Closed reduction: bones are manually coaxed into position by physician’s hands – Open reduction: bones are secured with pins or wires during surgery Healing time is 6–8 weeks Copyright © 2021 Pearson Education, Inc. All Rights Reserved Table 5.2 Common Types of Fractures (1 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Table 5.2 Common Types of Fractures (2 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Table 5.2 Common Types of Fractures (3 of 3) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bone Fractures (3 of 3) Repair of bone fractures involves four major events – Hematoma (blood-filled swelling, or bruise) is formed – Fibrocartilage callus forms ▪ Cartilage matrix, bony matrix, collagen fibers splint the broken bone – Bony callus replaces the fibrocartilage callus ▪ Osteoblasts and osteoclasts migrate in – Bone remodeling occurs in response to mechanical stresses Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.7 Stages in the Healing of a Bone Fracture Copyright © 2021 Pearson Education, Inc. All Rights Reserved Axial Skeleton Forms the longitudinal axis of the body Divided into three parts 1. Skull 2. Vertebral column 3. Bony thorax Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.8a The Human Skeleton (1 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.8b The Human Skeleton (1 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Skull (1 of 5) Two sets of bones form the skull 1. Cranium bones enclose the brain 2. Facial bones ▪ Hold eyes in anterior position ▪ Allow facial muscles to express feelings Bones are joined by sutures (immovable joints) Only the mandible is attached by a freely movable joint Copyright © 2021 Pearson Education, Inc. All Rights Reserved Skull (2 of 5) 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) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Skull (3 of 5) 14 facial bones 1, 2 Maxillae (pair) 3, 4 Palatine bones (pair) 5, 6 Lacrimal bones (pair) 7, 8 Zygomatic bones (pair) 9, 10 Nasal bones (pair) 11 Vomer bone 12, 13 Inferior nasal conchae (pair) 14 Mandible Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.9 Human Skull, Lateral View Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.10 Human Skull, Superior View (Top of Cranium Removed) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.11 Human Skull, Inferior View (Mandible Removed) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.12 Human Skull, Anterior and Posterior Views Copyright © 2021 Pearson Education, Inc. All Rights Reserved Vertebral Column (Spine) (1 of 3) Vertebral column provides axial support – Extends from skull to the pelvis 26 vertebral bones are separated by intervertebral discs – 7 cervical vertebrae are in the neck – 12 thoracic vertebrae are in the chest region – 5 lumbar vertebrae are associated with the lower back – Sacrum (formed by fusion of 5 vertebrae) – Coccyx (formed by fusion of 3–5 vertebrae) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.15 The Vertebral Column Copyright © 2021 Pearson Education, Inc. All Rights Reserved Vertebral Column (Spine) (2 of 3) Primary curvatures – Spinal curvatures of the thoracic and sacral regions – Present from 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 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.16 The C-Shaped Spine Typical of a Newborn Copyright © 2021 Pearson Education, Inc. All Rights Reserved Vertebral Column (Spine) (3 of 3) Common features of vertebrae – Body (centrum) – Vertebral arch ▪ Pedicle ▪ Lamina – Vertebral foramen – Transverse processes – Spinous process – Superior and inferior articular processes Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.17 A Typical Vertebra, Superior View Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.18a Regional Characteristics of Vertebrae Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.18b Regional Characteristics of Vertebrae Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.18c Regional Characteristics of Vertebrae Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.18d Regional Characteristics of Vertebrae Copyright © 2021 Pearson Education, Inc. All Rights Reserved Thoracic Cage Bony thorax, or thoracic cage, protects organs of the thoracic cavity Consists of three parts 1. Sternum 2. Ribs ▪ True ribs (pairs 1–7) ▪ False ribs (pairs 8–12) ▪ Floating ribs (pairs 11–12) 3. Thoracic vertebrae Copyright © 2021 Pearson Education, Inc. All Rights Reserved Appendicular Skeleton Composed of 126 bones – Limbs (appendages) – Pectoral girdle – Pelvic girdle Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.8a The Human Skeleton (2 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.8b The Human Skeleton (2 of 2) Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bones of the Upper Limbs (1 of 3) 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 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Bones of the Lower Limbs (1 of 4) 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 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (1 of 8) Joints are articulations – Occur where two or more bones meet Functions of joints – Hold bones together securely – Allow for mobility Two ways joints are classified – Functionally – Structurally Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (2 of 8) Functional joint classifications – Synarthroses ▪ Immovable joints – Amphiarthroses ▪ Slightly movable joints – Diarthroses ▪ Freely movable joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (3 of 8) Structural joint classifications – Fibrous joints ▪ Generally immovable – Cartilaginous joints ▪ Immovable or slightly movable – Synovial joints ▪ Freely movable Copyright © 2021 Pearson Education, Inc. All Rights Reserved Concept Link To understand the structural classes of joints more clearly, recall the properties of tissues that form the joints. Fibrous connective tissue contains many collagen fibers for strength. The three types of cartilage (hyaline, fibrocartilage, elastic) provide structure with some degree of flexibility, and fibrocartilage also has the ability to absorb compressive shock (Chapter 3, pp. 92–93). Synovial membranes contain areolar connective tissue and line the joint cavities of synovial joints (Chapter 4, pp. 107, 109). Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (4 of 8) Fibrous joints – Bones are united by fibrous tissue – Types ▪ Sutures – Immobile ▪ Syndesmoses – Allow more movement than sutures but still immobile – Found on the distal ends of tibia and fibula ▪ Gomphoses – Immobile – Found where the teeth meet the facial bones Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (5 of 8) Cartilaginous joints – Bones are connected by fibrocartilage – Types ▪ Synchrondrosis – Immobile – Found in epiphyseal plates of growing long bones ▪ Symphysis – Slightly movable – Found in the pubic symphysis, intervertebral joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (6 of 8) Synovial joints – Articulating bones are separated by a joint cavity – Synovial fluid is found in the joint cavity – Four distinguishing features of synovial joints 1. Articular cartilage 2. Articular capsule 3. Joint cavity 4. Reinforcing ligaments Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.28f Types of Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.28g Types of Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.28h Types of Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (7 of 8) Synovial joints – 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 Copyright © 2021 Pearson Education, Inc. All Rights Reserved Table 5.3 Summary of Joint Classes Structural class Structural Types Mobility characteristics Fibrous Bone ends/parts Suture (short fibers) Immobile (synarthrosis) united by collagenic Syndesmosis (longer fibers) Slightly mobile fibers Gomphosis (periodontal (amphiarthrosis) and immobile ligament) Immobile Cartilaginous Bone ends/parts Synchondrosis (hyaline Immobile united by cartilage cartilage) Symphysis Slightly movable (fibrocartilage) Synovial Bone ends/parts Plane Freely movable (diarthrosis; covered with Hinge movements depend on design articular cartilage Pivot of joint) and enclosed within Condylar an articular capsule Saddle lined with synovial Ball and Membrane socket Copyright © 2021 Pearson Education, Inc. All Rights Reserved Joints (8 of 8) Types of synovial joints based on shape – Plane joint – Hinge joint – Pivot joint – Condylar joint – Saddle joint – Ball-and-socket joint Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.29 General Structure of a Synovial Joint Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30a Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30b Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30c Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30d Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30e Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.30f Types of Synovial Joints Copyright © 2021 Pearson Education, Inc. All Rights Reserved Developmental Aspects of the Skeleton (1 of 6) Birth to adulthood – First “long bones” of a fetus are hyaline cartilage – Earliest “flat bones” of the fetal skull are fibrous membranes – As fetus grows, all bone models are converted to bone Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.31 Ossification Centers in the Skeleton of a 12-Week-Old Fetus Are Indicated by the Darker Areas Copyright © 2021 Pearson Education, Inc. All Rights Reserved Developmental Aspects of the Skeleton (2 of 6) Fetal skull – Fontanels are fibrous membranes connecting the cranial bones ▪ Known as “soft spots” ▪ Allow skull compression during birth ▪ Allow the brain to grow during later pregnancy and infancy ▪ Usually ossify by 2 years of age Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.32a The Fetal Skull Copyright © 2021 Pearson Education, Inc. All Rights Reserved Figure 5.32b The Fetal Skull Copyright © 2021 Pearson Education, Inc. 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