Chapter 5_Skeletal System P2.pdf

Part 2 Skeletal System 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...

Part 2 Skeletal System 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.15 The Vertebral Column Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.16 The C-Shaped Spine Typical of a Newborn Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.17 A Typical Vertebra, Superior View Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.18a Regional Characteristics of Vertebrae Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.18b Regional Characteristics of Vertebrae Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.18c Regional Characteristics of Vertebrae Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.18d Regional Characteristics of Vertebrae Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.19 Sacrum and Coccyx, Posterior View Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.20a The Bony Thorax (Thoracic Cage) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.20b The Bony Thorax (Thoracic Cage) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Appendicular Skeleton Composed of 126 bones – Limbs (appendages) – Pectoral girdle – Pelvic girdle Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.8a The Human Skeleton (2 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.8b The Human Skeleton (2 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Shoulder Girdle Also called pectoral girdle Composed of two bones that attach the upper limb to the axial skeletal 1. Clavicle 2. Scapula Light, poorly reinforced girdle Allows the upper limb a exceptional flexibility Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.21a Bones of the Shoulder Girdle Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.21b Bones of the Shoulder Girdle Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.21c Bones of the Shoulder Girdle Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.21d Bones of the Shoulder Girdle Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.22a Bones of the Right Arm and Forearm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.22b Bones of the Right Arm and Forearm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Upper Limbs (2 of 3) The forearm has two bones 1. Ulna—medial bone in anatomical position ▪ Proximal end articulation – Coronoid process and olecranon articulate with the humerus 2. Radius—lateral bone in anatomical position ▪ Proximal end articulation – Head articulates with the capitulum of the humerus Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.22c Bones of the Right Arm and Forearm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Upper Limbs (3 of 3) Hand – Carpals—wrist bones ▪ 8 bones arranged in two rows of 4 bones in each hand – Metacarpals—palm bones ▪ 5 per hand – Phalanges—fingers and thumb ▪ 14 phalanges in each hand ▪ In each finger, there are 3 bones ▪ In the thumb, there are only 2 bones Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.23 Bones of the Right Hand, Anterior View Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Pelvic Girdle (1 of 3) Formed by two coxal bones Composed of three pairs of fused bones 1. Ilium 2. Ischium 3. Pubis Pelvic girdle = two coxal bones, sacrum Pelvis = two coxal bones, sacrum, coccyx Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Pelvic Girdle (2 of 3) The total weight of the upper body rests on the pelvis Pelvis protects several organs – Reproductive organs – Urinary bladder – Part of the large intestine Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.24a The Bony Pelvis Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.24b The Bony Pelvis Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Pelvic Girdle (3 of 3) The female’s pelvis – Inlet is larger and more circular – Shallower, on the whole, and the bones are lighter and thinner – Ilia flare more laterally – Sacrum is shorter and less curved – Ischial spines are shorter and farther apart; thus, the outlet is larger – Pubic arch is more rounded because the angle of the pubic arch is greater Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.24c The Bony Pelvis Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.25a Bones of the Right Thigh and Leg Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.25b Bones of the Right Thigh and Leg Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Lower Limbs (2 of 4) The lower leg has two bones 1. Tibia—shinbone; larger and medially oriented ▪ Proximal end articulation – Medial and lateral condyles articulate with the femur to form the knee joint ▪ Distal end articulation – Medial malleolus forms the inner part of the ankle 2. Fibula—thin and sticklike; lateral to the tibia ▪ Has no role in forming the knee joint ▪ Distal end articulation – Lateral malleolus forms the outer part of the ankle Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.25c Bones of the Right Thigh and Leg Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Lower Limbs (3 of 4) Foot – Tarsals—7 bones ▪ Two largest tarsals are the: – Calcaneus (heel bone) – Talus – Metatarsals—5 bones form the sole of the foot – Phalanges—14 bones form the toes Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.26 Bones of the Right Foot, Superior View Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Bones of the Lower Limbs (4 of 4) Arches of the feet – Bones of the foot are arranged to form three strong arches – Two longitudinal – One transverse Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.27 Arches of the Foot Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Joints (2 of 8) Functional joint classifications – Synarthroses ▪ Immovable joints – Amphiarthroses ▪ Slightly movable joints – Diarthroses ▪ Freely movable joints Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Concept Link 3 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. 114–115). Synovial membranes contain areolar connective tissue and line the joint cavities of synovial joints (Chapter 4, pp. 129, 131). Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28a Types of Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28b Types of Joints Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28c Types of Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28d Types of Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28e Types of Joints Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28f Types of Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28g Types of Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.28h Types of Joints Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.29 General Structure of a Synovial Joint Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30a Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30b Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30c Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30d Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30e Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.30f Types of Synovial Joints Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.31 Ossification Centers in the Skeleton of a 12-Week-Old Fetus Are Indicated by the Darker Areas Copyright © 2022 Pearson Education, Ltd. 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 © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.32a The Fetal Skull Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.32b The Fetal Skull Copyright © 2022 Pearson Education, Ltd. All Rights Reserved.  Developmental Aspects of the Skeleton (3 of 6) Growth of cranium after birth is related to brain growth – Increase in size of the facial skeleton follows tooth development and enlargement of the respiratory passageways Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Skeleton (4 of 6) Size of cranium in relationship to body – 2 years old—skull is three-fourths the size of adult skull – 8 or 9 years old—skull is near adult in size and proportion – Between ages 6 and 11, the face grows out from the skull Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Skeleton (5 of 6) Skeletal changes – At birth, the head and trunk are proportionately much longer than the lower limbs – During puberty: ▪ Female pelvis broadens ▪ Entire male skeleton becomes more robust – By the end of adolescence: ▪ Epiphyseal plates become fully ossified Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.33a Differences in the Growth Rates for Some Parts of the Body Compared to Others Determine Body Proportions Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.33b Differences in the Growth Rates for Some Parts of the Body Compared to Others Determine Body Proportions Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Skeleton (6 of 6) Older adults – 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 Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.34 Osteoporosis Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 5.35 Vertebral Collapse Due to Osteoporosis Copyright © 2022 Pearson Education, Ltd. All Rights Reserved.