Organization of the Skeleton (Bone Review) Part 2

SACRUM & COCCYX 1. Sacrum Articulations a. The superior articular processes articulates with vertebrae L5 superiorly b. It articulates inferiorly with Co1 (coccyx 1) THORACIC CAGE (RIBS) & THE STERNUM 1. True Ribs (1-7) – Each one has its own costal cartilage connecting it to the sternum 2. False Ribs (8-12) – They lack independent cartilaginous connections to the sternum. a) Floating Ribs – Do not attach to the sternum 3. RIBS ARTICULATIONS a) Anteriorly – They articulate with the sternum b) Posteriorly – They articulate with the Thoracic Vertebrae STERNUM – Bony plate anterior to the heart 1. Manubrium (handle) – It is shaped like the knot of a necktie. It lies at the level of vertebrae T3-T4 a. Clavicular Notch – Articulates with the clavicles 2. Body – Longest part of the sternum. It lies at the level of vertebrae T5-T9 3. Xiphoid Process – Is small and pointy. It provides attachment for some abdominal muscles. AXIAL SKELETON PECTORAL (shoulder) GIRDLE – Supports the arm and links it to the axial skeleton. SCAPULA 1. Acromiom (acr=point; omi=shoulder) – Is a platelike extension of the scapular spine that forms the apex of the shoulder. a. It articulates with the clavicle (on its acromial end) 2. Glenoid (glen=socket/pit; oid=resembling) Cavity (fossa) – Is a shallow socket that articulates with the head of the humerus, forming the glenohumeral joint 3. Coracoid Process – Is shaped like a bent finger. It provides attachment for tendons of the biceps brachii & other muscles of the arm. 4. Spine of Scapula – Is a transverse ridge on the posterior surface CLAVICLE 1. Sternal End – Has a rounded hammerlike head 2. Acromial End – Is markedly flattened 3. Conoid Tubercle – A ligament attachment that faces toward the rear & slightly downward. HUMERUS 1. 2. 3. 4. 5. 6. 7. 8. 9. Head – Articulates with the glenoid cavity Greater Tubercle – Serve as a muscle attachment Lesser(smaller) Tubercle – Serve as a muscle attachment Capitulum (little head) – It is a smooth condyle shaped like a wide wire. a. It is on the lateral side. b. It articulates with the radius. Trochlea – It is a smooth condyle which is pulleylike. a. It is on the medial side b. It articulates with the Ulna Lateral Epicondyle – Medial Epicondyle – Protects the ulnar nerve. Olecranon Fossa – Is on the posterior side. a. Accommodates a process of the ulna called Olecranon Coronoid Fossa – Accommodates the Coronoid Process of the ulna when the forearm is flexed. RADIUS & ULNA RADIUS 1. Head – It is flat/circular 2. Radial Tuberosity – Is a rough prominence on the medial side 3. Styloid Process ULNA 1. Coronoid Process – It is on the anterior side. 2. Olecranon process – The bony point where you rest the elbow on a table. It is on the posterior side. 3. Throchlear Notch – It has deep C-shape. It wraps around the trochlea of the humerus. 4. Radial Notch of Ulna – Accommodates the edge of the head of the radius. It is on the lateral side. 5. Styloid Process of Ulna – Is a bony lump HAND 1. CARPALS a) Scaphoid (Navicular) – Boat shaped b) Lunate – Moon shaped c) Triquetral – Triangular shaped d) Pisiform – Pea-Shaped e) Hamate f) Capitate g) Trapezoid h) Trapezium 2. METACARPALS 3. PHALANGES Good Way to Remember the Order Sally Left The Party To Take Charlie Home PELVIC GIRDLE Consists of a complete ring composed of two Coxal (hip) bones & the Sacrum 1. 2. 3. 4. 5. 6. 7. Ilium Pubis – Most anterior portion of the hip bone Coxal (os coxal) Pubic Symphysis Obturator Foramen – large round-to triangular hole below the acetabulum. Acetabulum Ischium Organization of the Skeleton FEMUR & PATELLA FEMUR – Longest and strongest bone of the body. 1. Head – It is hemispherical & articulates with the acetabulum of the pelvis. 2. Greater Trochanter – 3. Lesser Trochanter – 4. Lateral Epicondyle – Widest point of the femur at the knee 5. Medial Epicondyle – Widest point of the femur at the knee 6. Lateral Condyle – A smooth round surface of the knee joint at the distal end of the femur 7. Medial Condyle – A smooth round surface of the knee joint at the distal end of the femur PATELLA – Is a roughly triangular sesamoid bone embedded in the tendon of the knee. TIBIA & FIBULA TIBIA 1. Lateral Condyle – Flat articular surface 2. Medial Condyle – Flat articular surface 3. Medial Malleolus (little hammer)– Prominent bony knob 4. Tibial Tuberosity – It is a rough anterior surface of the tibia, can be palpated right below the patella. 5. Anterior Crest – It is sharply angular. Located on the anterior side. 6. Tibial Plateau – Top, flat surface FIBULA 1. Head – It is thicker and broader. It is located on the proximal end. 2. Lateral Malleolus (little Hammer) FOOT 1. TARSALS a) Calcaneous (stone, chalk like) – Largest tarsal bone b) Talus – The most superior bone of the tarsals  Its superior trochlear surface articulates with the tibia  Anterior surface articulates with the navicular  Inferoposterior surface articulates with the calcaneous c) Cuboid d) Navicular (like a little boat) e) Lateral Cuneiform f) Intermediate Cuneiform g) Medial Cuneiform 2. METATARSALS 3. PHALANGES THE COMPACT BONE MODEL 5 3 2 1 7 4 6 9 7 8 Spongy Bone Key 1. 2. 3. 4. 5. 6. 7. 8. 9. Perosteum Endosteum Concentric Lamella Circumferential lamella Interstitial lamella Osteon Central (Haversian) Canal Volkmann’s Canal Sharpey’s (Perforating) fibers