APPENDICULA R SKELETON

The Appendicular Skeleton Pectoral girdle Attaches the upper limbs to the trunk Pelvic girdle Attaches the lower limbs to the trunk Upper and lower limbs differ in function BUT: Share the same structural plan

The Pectoral Girdle Consists of the clavicle and the scapula Pectoral girdles do not quite encircle the body completely Acromio- clavicular joint Clavicle Scapula Articulated pectoral girdle COLLAR BONE SHOULDER BLADE 

Clavicles Extend horizontally across the superior thorax Sternal end articulates with the manubrium Acromial end articulates with scapula Sternal (medial) end Posterior Anterior Acromial (lateral) end Right clavicle, superior view Right clavicle, inferior view Acromial end Trapezoid line Conoid tubercle Anterior Posterior Sternal end Impression for costoclavicular ligament Provide attachment for muscles Hold the scapulae and arms laterally Transmit compression forces from the upper limbs to the axial skeleton

Scapulae Have three borders Superior Medial (vertebral) Lateral (axillary) Have three angles Lateral, superior, and inferior Acromion Coracoid process Glenoid cavity Lateral border Suprascapular notch Superior border Superior angle Subscapular fossa Medial border Inferior angle Right scapula, anterior aspect

Figure 8-2b The scapula. Superior angle Suprascapular notch Supraspinous fossa Infraspinous fossa Coracoid process Acromion Lateral border Medial border Glenoid cavity at lateral angle Spine Right scapula, posterior aspect

Anterior Right scapula, lateral aspect Posterior Supraspinous fossa Infraspinous fossa Subscapular fossa Supraspinous fossa Supraglenoid tubercle Coracoid process Acromion Glenoid cavity Infraglenoid tubercle Subscapular fossa Infraspinous fossa Inferior angle Spine IT’S JUST A WEIRD-LOOKING BONE!!

The Upper Limb 30 bones form each upper limb Grouped into bones of the: Arm Forearm Hand

Greater tubercle Lesser tubercle Inter- tubercular sulcus Head of humerus Anatomical neck Deltoid tuberosity Lateral supracondylar ridge Radial fossa Capitulum Coronoid fossa Medial epicondyle Trochlea Anterior view Region of the upper limb between the shoulder and elbow Humerus The only bone of the arm Longest and strongest bone of the upper limb Articulates with the scapula at the shoulder Articulates with the radius and ulna at the elbow Head of humerus Anatomical neck Radial groove Medial supracondylar ridge Olecranon fossa Medial epicondyle Trochlea Posterior view Lateral epicondyle Deltoid tuberosity Surgical neck Greater tubercle Arm

DETAILED views of articulation at the elbow. (Humerus of the right arm) Anterior view at the elbow region Radius Radial tuberosity Head of radius Capitulum Humerus Radial notch Coronoid process of ulna Trochlea Medial epicondyle Coronoid fossa Ulna Posterior view of extended elbow Ulna Radius Neck Head Lateral epicondyle Medial epicondyle Olecranon Humerus Olecranon fossa

Forear m Formed from the radius and ulna Proximal ends articulate with the humerus Distal ends articulate with carpals The interosseous membrane Interconnects radius and ulna In anatomical position; the radius is lateral and the ulna is medial ulna radius

ULNA: Main bone responsible for forming the elbow joint with the humerus Hinge joint -allows forearm to bend on arm Distal end is separated from carpals by fibrocartilage Plays little to no role in hand movement Radial notch of the ulna Head Neck Radial tuberosity Olecranon Troclear notch Coronoid process Proximal radioulnar joint Radius Radial styloid process Distal radioulnar joint Ulnar notch of the radius Head of ulna Ulnar styloid process Interosseous membrane Ulna Anterior view Ulnar notch of the radius Head of ulna Ulnar styloid process Radius Radial styloid process Posterior view Interosseous membrane Neck of radius Head of radius Ulna Olecranon Radius: Medially—the head of the radius articulates with the radial notch of the ulna Contributes heavily to the wrist joint Distal radius articulates with carpal bones Moves the hand

Proximal portion of ulna, lateral view View Radial notch Coronoid process Trochlear notch Olecranon Radial styloid process Distal ends of the radius and ulna at the wrist Head of ulna Ulnar styloid proces Articulation for lunate Articulation for scaphoid Ulnar notch of radius View Major landmarks of the ulna Olecranon Radial notch Trochlear notch Coronoid process Ulnar styloid process When the radius moves, the hand moves with it.

Radius Major landmarks of the radius: Head Neck Radial tuberosity Radial styloid process

Han d Includes the following bones Carpus—wrist Metacarpals—palm Phalanges—fingers Phalanges Distal Middle Proximal Sesamoid bones Trapezium Trapezoid Scaphoid Carpals Hamate Capitate Pisiform Triquetrum Lunate Ulna Radius Anterior view of right hand II IIIIV V I 8 Carpal bones (make up the carpus) Are arranged in two irregular rows Proximal row from lateral to medial Scaphoid, lunate, triquetrum, and pisiform Distal row from lateral to medial Trapezium, trapezoid, capitate, and hamate A mnemonic to help remember carpals: “Sally left the party to take Carmen home”

Metacarpus Five metacarpals radiate distally from the wrist Metacarpals form the palm Numbered I-V, beginning with the pollex (thumb) Bases articulate proximally with the distal row of carpals Heads articulate distally with the proximal phalanges IV III II V I

Consists of three separate bones in childhood Ilium, ischium, and pubis Bones fuse, retain separate names Ilium Pubis Ischium Coxal Bones 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 Pelvic Girdle

Table 8-2 Comparison of the Male and Female Pelves (3 of 3)

The Lower Limb Carries the entire weight of the erect body Bones of lower limb are thicker and stronger than those of upper limb Divided into three segments Thigh, leg, and foot

Thigh and Kneecap The region of the lower limb between the hip and the knee Femur —the single bone of the thigh Longest and strongest bone of the body Ball-shaped head of the femur articulates with the acetabulum Patella Sesamoid – embedded in a tendon that secures the quadricep muscles Neck Lateral epicondyle Patellar surface Anterior view Femur (thigh bone) Posterior view Medial epicondyle Adductor tubercle Medial condyle Intercondylar fossa Lateral epicondyle Lateral condyle Medial and lateral supra- condylar lines Linea aspera Gluteal tuberosity Intertrochanteric line Lesser trochanter Head Greater trochanter Inter- trochanteric crest Fovea capitis

Leg Tibia — think “tough” - Receives weight of the body from the femur Fibula — think “fine” Does not contribute to knee joint Stabilizes the ankle joint Interosseous membrane- -Connects the tibia and fibula Intercondylar eminence Lateral condyle Head Superior tibiofibular joint Tibial tuberosity Medial condyle Interosseous membrane Anterior border Tibia Fibula Inferior tibiofibular joint Lateral malleolus Anterior view Medial malleolus Inferior articular surface Medial condyle Articular surface of medial condyle Head of fibula Articular surface of lateral condyle Fibula Interosseous membrane Tibia Fibular notch Medial malleolus Inferior articular surface Posterior view Lateral malleolus

The Foot Composed of Tarsus, metatarsus, and the phalanges Important functions Supports body weight Acts as a lever to propel body forward when walking Segmentation makes foot pliable and adapted to uneven ground

Body weight is borne primarily by the talus and calcaneus Trochlea of talus articulates with the tibia Hallux = big toe Metatarsals and 14 phalanges

Figure 8-11b Bones of the right foot. Medial view Medial cuneiform Calcaneus Calcaneal tuberosity First metatarsal Intermediate cuneiform Navicular Talus Medial malleolar facet Sustentac- ulum tali (talar shelf) Calcaneus Talus Lateral malleolar facet Lateral view Cuboid Fifth metatarsal Lateral cuneiform Intermediate cuneiform Navicular Medial  And Lateral VIEWS OF THE FOOT