Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 7 The Skeletal System:The Axial Skeleton • Axial Skeleton – 80 bones – lie along longitudinal axis – skull, hyoid, vertebrae, ribs, sternum, ear ossicles • Appendicular Skeleton – 126 bones – upper & lower limbs and pelvic & pectoral girdles 7-1 The Skeletal System-Function 1. Support 2. Protection 3. Movement 4. Mineral storage 7-2 Types of Bones • 5 basic types of bones: 1. long = compact 2. short = spongy except surface 3. flat = plates of compact enclosing spongy 4. irregular = variable 5. sesamoid = develop in tendons or ligaments (patella) • Sutural bones = in joint between skull bones 7-3 Anatomy of a Long Bone • • • • Diaphysis = shaft Epiphysis = one end of a long bone Metaphysis = growth plate region Articular cartilage over joint surfaces acts as friction & shock absorber • Medullary cavity = marrow cavity • Endosteum = lining of marrow cavity • Periosteum = tough membrane covering bone but not the cartilage – fibrous layer = dense irregular CT – osteogenic layer = bone cells & blood vessels that nourish or help with repairs 7-4 Compact or Dense Bone • Looks like solid hard layer of bone • Makes up the shaft of long bones and the external layer of all bones • Resists stresses produced by weight and movement 7-5 The Trabeculae of Spongy Bone • Latticework of thin plates of bone called trabeculae oriented along lines of stress • Spaces in between these struts are filled with red marrow where blood cells develop • Found in ends of long bones and inside flat bones such as the hipbones, sternum, sides of skull, and ribs. 7-6 Bone Growth and Repair 7-7 The Skull • 8 Cranial bones – protect brain & house ear ossicles – muscle attachment for jaw, neck & facial muscles • 14 Facial bones – protect delicate sense organs -- smell, taste, vision – support entrances to digestive and respiratory systems 7-8 The 8 Cranial Bones Frontal Parietal (2) Temporal (2) Occipital Sphenoid Ethmoid 7-9 14 Facial Bones Nasal (2) Mandible (1) Inferior nasal conchae (2) Maxillae (2) Lacrimal (2) Zygomatic (2) Palatine (2) Vomer (1)7-10 Le Fort Fractures 7-11 Sutures • Lambdoid suture unites parietal and occipital • Sagittal suture unites 2 parietal bones 7-12 Sutures • Coronal suture unites frontal and both parietal bones • Squamous suture unites parietal and temporal bones 7-13 Paranasal Sinuses • • • • Paired cavities in ethmoid, sphenoid, frontal and maxillary Lined with mucous membranes and open into nasal cavity Resonating chambers for voice, lighten the skull Sinusitis is inflammation of the membrane (allergy) 7-14 Fontanels of the Skull at Birth. • Dense connective tissue membrane-filled spaces (soft spots) • Unossified at birth but close early in a child's life. • Fetal skull passes through the birth canal. • Rapid growth of the brain during infancy 7-15 Vertebral Column • Backbone or spine built of 26 vertebrae • Five vertebral regions – cervical vertebrae (7) in the neck – thoracic vertebrae ( 12 ) in the thorax – lumbar vertebrae ( 5 ) in the low back region – sacrum (5, fused) – coccyx (4, fused) 7-16 Normal Curves of the Vertebral Column • Primary curves – thoracic and sacral are formed during fetal development • Secondary curves – cervical if formed when infant raises head at 4 months – lumbar forms when infant sits up & begins to walk at 1 year 7-17 Typical Vertebrae • Body – weight bearing • Vertebral arch – pedicles – laminae • Vertebral foramen • Seven processes – 2 transverse – 1 spinous – 4 articular • Vertebral notches 7-18 Typical Cervical Vertebrae (C3-C7) • Smaller bodies • Larger spinal canal • Transverse processes – shorter – transverse foramen for vertebral artery • Spinous processes of C2 to C6 often bifid • 1st and 2nd cervical vertebrae are unique – atlas & axis 7-19 Atlas & Axis (C1-C2) • Atlas -- ring of bone, superior facets for occipital condyles – nodding movement at atlanto-occipital joint signifies “yes” • Axis -- dens or odontoid process is body of atlas – pivotal movement at atlanto-axial joint signifies “no” 7-20 Thoracic Vertebrae (T1-T12) • Larger and stronger bodies • Longer transverse & spinous processes • Facets or demifacets on body for head of rib • Facets on transverse processes (T1-T10) for tubercle of rib 7-21 Lumbar Vertebrae • Strongest & largest • Short thick spinous & transverse processes – back musculature 7-22 Sacrum and Coccyx • • • • Union of 5 vertebrae (S1 - S5) by age 30 Sacral canal ends at sacral hiatus Auricular surface & sacral tuberosity of SI joint Coccyx- Union of 4 vertebrae (Co1 - Co4) by age 30 7-23 Thorax – Bony cage flattened from front to back – Sternum (breastbone) – Ribs • 1-7 are true ribs • 8-12 are false ribs • 11-12 are floating – Costal cartilages – Bodies of the thoracic vertebrae. 7-24 Sternum • Manubrium – 1st & 2nd ribs – clavicular notch • Body – costal cartilages of 2-10 ribs • Xiphoid – ossifies by 40 – CPR position – abdominal mm. • Sternal puncture – biopsy 7-25 Ribs Fracture at site of greatest curvature. • • • • Increase in length from ribs 1-7, thereafter decreasing Head and tubercle articulate with facets Body with costal groove containing nerve & blood vessels Intercostal spaces contain intercostal muscles 7-26 Rib Articulation • Tubercle articulates with transverse process • Head articulates with vertebral bodies 7-27 Chapter 8 Skeletal System: Appendicular Skeleton • Pectoral girdle • Pelvic girdle • Upper limbs • Lower limbs 7-28 Pectoral (Shoulder) Girdle • Consists of scapula and clavicle • Clavicle articulates with sternum (sternoclavicular joint) • Clavicle articulates with scapula (acromioclavicular joint) • Scapula held in place by muscle only • Upper limb attached to pectoral girdle at shoulder (glenohumeral joint) 7-29 Upper Extremity • Each upper limb = 30 bones – humerus within the arm – ulna & radius within the forearm – carpal bones within the wrist – metacarpal bones within the palm – phalanges in the fingers • Joints – shoulder (glenohumeral), elbow, wrist, metacarpophalangeal, interphalangeal 7-30 Pelvic Girdle and Hip Bones • Pelvic girdle = two hipbones united at pubic symphysis – articulate posteriorly with sacrum at sacroiliac joints • Each hip bone = ilium, pubis, and ischium – fuse after birth at acetabulum • Bony pelvis = 2 hip bones, sacrum and coccyx 7-31 Lower Extremity • Each lower limb = 30 bones – femur and patella within the thigh – tibia & fibula within the leg – tarsal bones in the foot – metatarsals within the forefoot – phalanges in the toes • Joints – hip, knee, ankle – proximal & distal tibiofibular – metatarsophalangeal 7-32 Chapter 9: Classification of Joints • Structural classification based upon: – presence of space between bones-Synovial space – type of connective tissue holding bones together • collagen fibers • cartilage • joint capsule & accessory ligaments • Fibous Joints, Cartilageous and synovial 7-33 Fibrous Joints • Lack a synovial cavity • Bones held closely together by fibrous connective tissue • Little or no movement • 3 structural types – Sutures - skull – Syndesmoses- growth plate – Gomphosese.eg. teeth 7-34 Sutures • Thin layer of dense fibrous connective tissue unites bones of the skull • Immovable • If fuse completely in adults 7-35 Cartilaginous Joints • Lacks a synovial cavity • Allows little or no movement • Bones tightly connected by fibrocartilage or hyaline cartilage • 2 types – Synchondroses=growth plate – symphyses 7-36 Synchondrosis-Growth Plates -Epiphyseal Plate- • Connecting material is hyaline cartilage • Immovable • =Epiphyseal plate or joints between ribs and sternum 7-37 Symphysis • Fibrocartilage is connecting material • Slightly movable • E.g. Intervertebral discs and pubic symphysis 7-38 Synovial Joints • Synovial cavity separates articulating bones • Freely moveable • cartilage – reduces friction – absorbs shock • capsule – surrounds joint – thickenings in fibrous capsule called ligaments • Synovial membrane – inner lining of capsule – secretes synovial fluid containing hyaluronic acid slippery) – brings nutrients to cartilage 7-39 Other Special Features • Accessory ligaments • Articular discs or menisci – attached around edges to capsule – allow 2 bones of different shape to fit tightly – increase stability of knee - torn cartilage • Bursae = saclike structures between structures -bursitis – skin/bone or tendon/bone or ligament/bone 7-40 Planar Joint (Plane)-Gliding • Bone surfaces are flat or slightly curved • Side to side movement only • Rotation prevented by ligaments • Examples – intercarpal or intertarsal joints – sternoclavicular joint – vertebrocostal joints 7-41 Hinge Joint • Convex surface of one bones fits into concave surface of 2nd bone • Uniaxial like a door hinge • Examples – Knee, elbow, ankle, interphalangeal joints • Movements produced – flexion = decreasing the joint angle – extension = increasing the angle – hyperextension = opening the joint beyond the anatomical position 7-42 Flexion, Extension & Hyperextension 7-43 Pivot Joint • Rounded surface of bone articulates with ring formed by 2nd bone & ligament • Monoaxial since it allows only rotation around longitudinal axis • Examples – Proximal radioulnar joint • supination • pronation – Atlanto-axial joint • turning head side to side “no” 7-44 Abduction and Adduction Condyloid joints Ball and Socket joints 7-45 Ball and Socket Joint • Ball fitting into a cuplike depression • Multiaxial – flexion/extension – abduction/adduction – rotation • Examples – shoulder joint – hip joint 7-46 Circumduction • Movement of a distal end of a body part in a circle • Combination of flexion, extension, adduction and abduction • Occurs at ball and socket, saddle and condyloid joints 7-47 Rotation • Bone revolves around its own longitudinal axis – medial rotation is turning of anterior surface in towards the midline – lateral rotation is turning of anterior surface away from the midline • At ball & socket and pivot type joints 7-48 Special Movements of Mandible • Elevation = upward • Depression = downward • Protraction = forward • Retraction = backward 7-49 Special Hand & Foot Movements Inversion Eversion Dorsiflexion Plantarflexion Pronation Supination 7-50 Homework • See sheet 7-51