PowerPoint® Lecture Slides The Appendicular Skeleton prepared by Leslie Hendon University of Alabama, Birmingham • Pectoral girdle • Attaches the upper limbs to the trunk Pelvic girdle C H A P T E R • 8 • Attaches the lower limbs to the trunk Part 1 • Upper and lower limbs differ in function Bones, • Share the same structural plan Part 1: The Appendicular Skeleton Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. The Pectoral Girdle The Pectoral Girdle • Consists of the clavicle and the scapula • Provides attachment for many muscles that • Pectoral girdles do not quite encircle the move the upper limb body completely • Girdle is very light and upper limbs are • Medial end of each clavicle articulates with mobile the manubrium and first rib • Only clavicle articulates with the axial skeleton • Laterally—the ends of the clavicles join the • Socket of the shoulder joint (glenoid cavity) is scapulae shallow • Scapulae do not join each other or the axial • Good for flexibility, bad for stability skeleton Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Articulated Pectoral Girdle Clavicles Sternal (medial) Clavicle end Acromio- clavicular Scapula Posterior joint Anterior Acromial (lateral) end (b) Right clavicle, superior view Acromial end Anterior Trapezoid line Sternal end Posterior Tuberosity for PLAY Shoulder Conoid tubercle costoclavicular ligament (a) Articulated pectoral girdle (c) Right clavicle, inferior view Copyright © 2011 Pearson Education, Inc. Figure 8.1a Copyright © 2011 Pearson Education, Inc. Figure 8.1b, c 1 Scapulae Structures of the Scapula Acromion Suprascapular notch Superior border • Lie on the dorsal surface of the rib cage Coracoid Superior process angle • Located between ribs 2–7 Glenoid cavity • Have three borders • Superior • Medial (vertebral) • Lateral (axillary) Subscapular Lateral border fossa • Have three angles Medial border • Lateral, superior, and inferior (a) Right scapula, anterior aspect Inferior angle Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Figure 8.2a Structures of the Scapula Structures of the Scapula Coracoid process Supraspinous fossa Suprascapular notch Acromion Supraglenoid tubercle Superior Acromion angle Supraspinous fossa Coracoid Supraspinous process fossa Glenoid cavity Spine Glenoid Spine Infraspinous Subscapular cavity at lateral fossa fossa angle Infraglenoid Infraspinous Infraspinous fossa tubercle fossa Posterior Anterior Subscapular fossa Medial border Lateral border (c) Right scapula, lateral aspect Inferior angle (b) Right scapula, posterior aspect Copyright © 2011 Pearson Education, Inc. Figure 8.2b Copyright © 2011 Pearson Education, Inc. Figure 8.2c The Upper Limb Arm • 30 bones form each upper limb • Region of the upper limb between the • Grouped into bones of the: shoulder and elbow • Arm • Humerus • Forearm • The only bone of the arm • Hand • Longest and strongest bone of the upper limb • Articulates with the scapula at the shoulder • Articulates with the radius and ulna at the elbow Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. 2 Structures of the Humerus of the Right Arm Structures of the Humerus of the Right Arm: the elbow Greater tubercle Head of humerus Head of humerus Greater tubercle Lesser tubercle Humerus Anatomical neck Anatomical neck Humerus Coronoid Olecranon Intertubercular Surgical neck fossa sulcus fossa Medial Capitulum Olecranon epicondyle process Radial groove Deltoid tuberosity Deltoid tuberosity Lateral epicondyle Medial Head of Trochlea epicondyle Medial supracondylar radius ridge Coronoid Radial process of Head Lateral supracondylar Coronoid fossa ulna tuberosity Neck ridge Olecranon fossa Radial notch Radial fossa Medial epicondyle Radius Ulna Ulna Medial epicondyle Lateral epicondyle Radius Capitulum (b) Posterior view Trochlea (a) Anterior view Trochlea (c) Anterior view at the elbow region (d) Posterior view of extended elbow Copyright © 2011 Pearson Education, Inc. Figure 8.3a, b Copyright © 2011 Pearson Education, Inc. Figure 8.3c, d Forearm Ulna and Radius • Formed from the radius and ulna • Ulna • Proximal ends articulate with the humerus • Main bone responsible for forming the elbow joint with the humerus • Hinge joint allows forearm to bend on arm • Distal ends articulate with carpals • Distal end is separated from carpals by fibrocartilage • Radius and ulna articulate with each other at the • Plays little to no role in hand movement proximal and distal radioulnar joints • Radius • The interosseous membrane • Superior surface of the head of the radius articulates with the capitulum • Interconnects radius and ulna • Medially—the head of the radius articulates with the radial notch of the • In anatomical position; the radius is lateral and the ulna ulna is medial • Contributes heavily to the wrist joint • Distal radius articulates with carpal bones • When radius moves, the hand moves with it Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Proximal Part of the Ulna Radius and Ulna Olecranon process View Trochlear notch Olecranon Radial notch Olecranon process process of the ulna Head of radius Coronoid process Head Trochlear notch Neck Neck of radius Radial Coronoid process Radial notch tuberosity Proximal radioulnar joint (c) Proximal portion of ulna, lateral view Interosseous Interosseous membrane membrane Ulnar notch of radius Ulna Ulna Articulation Radius for lunate Ulnar notch of the radius Articulation Ulnar notch of Radius for scaphoid the radius Head of ulna Head of ulna Styloid Styloid process Styloid process Distal radioulnar joint process of radius Styloid process of ulna of ulna (a) Anterior view (b) Posterior view Styloid process of radius View Head of Styloid ulna process (d) Distal ends of the radius and ulna at the wrist Copyright © 2011 Pearson Education, Inc. Figure 8.4a, b Copyright © 2011 Pearson Education, Inc. Figure 8.4c, d 3 Proximal Ends of the Radius and Ulna at the Hand elbow • Includes the following bones Humerus Humerus Coronoid Olecranon fossa fossa • Carpus—wrist Medial Capitulum Olecranon epicondyle • Metacarpals—palm process Lateral epicondyle • Phalanges—fingers Medial Head of Trochlea epicondyle radius Coronoid Radial process of Head ulna tuberosity Neck Radial notch Radius Ulna Ulna Radius (c) Anterior view at the elbow region (d) Posterior view of extended elbow Copyright © 2011 Pearson Education, Inc. Figure 8.3c, d Copyright © 2011 Pearson Education, Inc. Carpus Bones of the Hand • Forms the true wrist—the proximal region of the hand Phalanges • Gliding movements occur between carpals Distal Middle • Composed of eight marble-sized bones Proximal • Carpal bones • Are arranged in two irregular rows • Proximal row from lateral to medial Metacarpals Head • Scaphoid, lunate, triquetral, and pisiform Sesamoid Shaft bones Base Carpals 4 3 5 2 • Distal row from lateral to medial Hamate 1 Carpals 2 3 4 1 5 Carpals Capitate Trapezium Hamate • Trapezium, trapezoid, capitate, and hamate Pisiform Trapezoid Capitate Triquetrum Scaphoid Triquetrum • A mnemonic to help remember carpals: Lunate Lunate • Sally left the party to take Carmen home Ulna Radius Ulna (a) Anterior view of right hand (b) Posterior view of right hand Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Figure 8.6a, b • Metacarpus • Five metacarpals radiate distally from the wrist • Metacarpals form the palm • Numbered 1–5, beginning with the pollex (thumb) • Articulate proximally with the distal row of carpals • Articulate distally with the proximal phalanges • Phalanges • Numbered 1–5, beginning with the pollex (thumb) • Except for the thumb, each finger has three phalanges • Proximal, middle, and distal Figure 8.6b Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. 4 Pelvic Girdle • Attaches lower limbs to the spine • Supports visceral organs • Attaches to the axial skeleton by strong ligaments • Acetabulum is a deep cup that holds the head of the femur • Lower limbs have less freedom of movement • Are more stable than the arm • Consists of paired hip bones (coxal bones) • Hip bones unite anteriorly with each other • Articulates posteriorly with the sacrum Table 8.1 Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Bones of the Pelvic Girdle The Pelvic Girdle Base of sacrum Iliac crest • Consists of three separate bones in childhood Sacroiliac joint • Ilium, ischium, and pubis Iliac fossa Anterior superior • Bones fuse, retain separate names to regions of the iliac spine coxal bones llium Sacral promontory Coxal • Acetabulum Anterior bone Sacrum (os coxae inferior iliac • A deep hemispherical socket on lateral pelvic surface or hip spine bone) Pubis Coccyx Pelvic brim Acetabulum Pubic tubercle Ischium Pubic crest Pubic (a) Pelvic girdle Pubic arch symphysis PLAY Pelvis Copyright © 2011 Pearson Education, Inc. Figure 8.8a Copyright © 2011 Pearson Education, Inc. Ischium Ilium • Forms posteroinferior region of the coxal bone • Anteriorly—joins the pubis • Large, flaring bone • Ischial tuberosities • Forms the superior region of the coxal bone • Are the strongest part of the hip bone • Site of attachment for many muscles Pubis • Articulation with the sacrum forms sacroiliac joint • Forms the anterior region of the coxal bone • Lies horizontally in anatomical position • Pubic symphysis • The two pubic bones are joined by fibrocartilage at the midline • Pubic arch—inferior