Anatomy

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The Appendicular Skeleton Objectives • Identify the bones of the pectoral girdle and upper limbs, their functions and their

features. • Identify the bones of the pelvic girdle and lower limbs, their functions and their

features. • Compare the male and female pelvic structure. • Explain how the skeleton can reveal significant information about the individual. • Compare male and female skeletons. • Describe the effect of aging on the skeleton.

The Pectoral Girdle

Pectoral girdle (shoulder girdle) • Articulates the upper limbs with the trunk/axial skeleton at the sternoclavicular joint • Consists of the clavicle and scapula articulating at the acromioclavicular joint • Not a complete girdle as there is no posterior bony union • This results in great range of motion, but joint instability

Clavicle Bony landmarks: acromial end, sternal end, conoid tubercle (inferior aspect), be able to distinguish left clavicle from right clavicle

Scapula Spine Superior border Acrimion process Superior angle Supraspinous fossa Inferior angle Infraspinous fossa Glenoid fossa (cavity) Subscapular fossa Coracoid process Superior border Medial (vertebral) border Lateral (axillary) border

Upper Limbs (60 bones total) • Scapula articulates with upper limb via humerus at the glenohumoral joint

Humerus • Articulates with scapula at glenohumeral joint; and radius and ulna at the elbow joint

Head Medial epicondyle Anatomical neck Lateral epicondyle Surgical neck Trochlea Greater tubercle Capitulum Lesser tubercle Coronoid fossa (anterior) Intertubercular groove Radial fossa (anterior) Deltoid tuberosity Olecranon fossa (posterior)

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Radius Head Styloid process Neck Notch Tuberosity

Ulna Olecranon process Styloid process Coronoid process Head (distal) Trochlear (semilunar) notch Tuberosity Radial notch

Carpal Bones and Hand • Carpus forms wrist • Carpals are two rows of four bones (eight total bones)

Proximal row starting at thumb: scaphoid, lunate, triquitrum, pisiform Distal row: trapezium, trapezoid, capitate, hamate Mnemonic: Some lovers try positions that they can’t handle

• Metacarpals of hand: Numbered I – V starting at thumb using Roman numerals • Fingers comprised of phalanges (phalanx, singular)

Each finger has three phlanges, Pollex (thumb) has two Fingers numbered I – V starting at thumb, but each does have it’s own name: thumb or pollex, index, middle, ring, little

The Pelvic Girdle and Lower Limbs

The Pelvic Girdle • More massive than the pectoral girdle, less mobility, more stability • Consists of two os coxae

• Fusion of ilium, ischium, and pubis into a single bone (by 12-16 yrs.) Ilium

Iliac crest Posterior superior iliac spine Anterior superior iliac spine Posterior inferior iliac spine Anterior inferior iliac spine Greater sciatic notch Iliac fossa Auricular fossa

Ischium Ischial spine Ischial tuberosity Ramus Lesser sciatic notch

Pubis Pubic symphysis (symphysis pubis) Tubercle Superior ramus Inferior ramus

Pelvis • Composed of the hipbones, sacrum, and coccyx • Subdivided into the false (greater) and true (lesser) pelvis • Pelvic brim divides the above

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Male vs. Female Pelvis The female pelvis has the following distinctions:

Greater pelvic outlet: greater distance between ischial spines Flared ilia Greater distance between PSIS, showing therefore more sacrum Subpubic angle is greater than 100° (Males are less than 90°)

Lower Limbs (60 bones total) • Femur is the longest bone in the body

• Articulates with the tibia at the knee • Patella is a large sesamoid bone • Fibula parallels tibia laterally

Femur Head Medial condyle Fovea capitus Lateral condyle Neck Intercondylar fossa Greater trochanter Medial epicondyle Lesser trochanter Lateral epicondyle Intertrochanteric crest (posterior) Patellar surface Intertrochanteric line (anterior) Linea aspera

Tibia Medial condyle Tuberosity Lateral condyle Medial malleolus Intercondylar eminence

Fibula Head Lateral malleolus

Patella Sesamoid bone that provides mechanical advantage to muscular forces at knee

Tarsal bones and Foot • Seven tarsal bones: talus (articulates with tibia), calcaneus (heel), cuboid, navicular,

cuneiforms (medial, intermediate, lateral; or 1st, 2nd & 3rd) • Pattern of metatarsal bones and phalanges parallels that of the hand • When standing, body weight is mostly transferred from the talus to the calcaneus

• Rest is passed on to metatarsals • Weight transfer occurs along longitudinal arch

• Transverse arch also exists