Appendicular Skeleton The Skeleton Appendicular Skeleton

Appendicular Skeleton Allows us to move and manipulate objects Includes all bones besides axial skeleton: the limbs the supportive girdles

Appendicular Skeleton Pectoral Girdle

Pectoral Girdle Also called the shoulder girdle Connects the arms to the body Positions the shoulders Provides a base for arm movement Consists of the scapula (shoulder blade) and the clavicle (collarbone)

Pectoral Girdle Scapula (shoulder blade) Features to know Scapular spine Acromion process Corocoid process Glenoid cavity (glenoid fossa) Borders – superior, medial, lateral Corners – superior angle, inferior angle, lateral angle

Pectoral Girdle Clavicle S-shaped bones Run from the manubrium to the acromion on the scapula

Appendicular Skeleton Upper Limb

Upper Limb Consists of arms, forearms, wrists, and hands Note: arm (brachium) = 1 bone, the humerus

Upper Limb Humerus Also called the arm The long, upper armbone Articulates with the pelvic girdle and forearm

Upper Limb Humerus Features Head – articulates with glenoid fossa Medial and lateral epicondyles Trochlea – articulates with ulna Capitulum – articulates with radius Olecranon fossa

Upper Limb Forearm Consists of 2 long bones: ulna (medial) Olecranon process radius (lateral)

Upper Limb Wrist 8 carpal bones: 4 proximal carpal bones (starting Laterally) Scaphoid bone Lunate bone Triquetrum Pisiform bone 4 distal carpal bones (starting Laterally) Trapezium: Trapezoid bone: Capitate bone: Hamate bone:

Upper Limb Hand (Metacarpals) Fingers/Thumb 5 long bones of the hand Numbered I–V from lateral (thumb) to medial Fingers/Thumb Pollex (thumb): 2 phalanges (proximal, distal) Fingers: 3 phalanges (proximal, middle, distal)

Appendicular Skeleton Pelvic Girdle

Pelvic Girdle Os Coxae Made up of 3 fused bones: ilium (articulates with sacrum) ischium pubis

Pelvic Girdle Differences Also called the hip socket Is the meeting point of the ilium, ischium, and pubis Is on the lateral surface of the os coxae Articulates with head of the femur (lunate surface)

Pelvic Girdle Ilium Ischium Pubis Iliac crest Anterior superior iliac spine (ASIS) Posterior superior iliac spine (PSIS) Ischium Ischial tuberocity Pubis Pubic symphysis

Pelvic Girdle Differences between male and female pelvic girdles. Female pelvis: smoother lighter less prominent muscle and ligament attachments Modifications for Childbearing Enlarged pelvic outlet Broad pubic angle (> 100°) Less curvature of sacrum and coccyx Wide, circular pelvic inlet Broad, low pelvis Ilia project laterally, not upwards

Appendicular Skeleton Lower Limb

Lower Limb Consists of: Femur (thigh) Patella (kneecap) Tibia and fibula (leg) Tarsals (ankle) Metatarsals (foot) Phalanges (toes)

Lower Limb Femur Largest, heaviest bone Features Head – articulates with acetabulum Neck Greater trochanter Medial and lateral epicondyles: above the knee joint Medial and lateral condyles: form part of knee joint

Lower Limb Patella (knee cap) A sesamoid bone Formed within tendon of quadriceps muscles

Lower Limb Tibia (shin bone) Medial bone in lower leg Supports body weight Features Medial and Lateral Condyles Tibial tuberosity Medial Malleolus – medial “ankle bone”

Lower Limb Fibula Lateral bone in lower leg Does not support body weight Features Head Lateral Malleolus – lateral “ankle bone”

Lower Limb Ankle (Tarsus) Consists of 7 tarsal bones Talus Calcaneus (heel bone) Cuboid bone Navicular bone Medial cuneiform Intermediate cuneiform Lateral cuneiform

Lower Limb Feet (Metatarsals) Toes (phalanges) 5 long bones of foot Numbered I–V, medial to lateral Toes (phalanges) Hallux: big toe, 2 phalanges (distal, proximal) Other 4 toes: 3 phalanges (distal, medial, proximal)

Lower Limb Feet Arches Arches transfer weight from 1 part of the foot to another Longitudinal arch Transverse arch Pes planus – flat arches Pes cavus – high arches