152 Anatomy & Physiology Essentials Copyright Goodheart-Willcox Co., Inc. The configuration of the metatarsal bones forms two important arches (Figure 5.33). The longitudinal arch runs lengthwise from the calcaneus to the heads of the metatarsals. The transverse arch runs perpendicular to the longitudinal arch and typically causes the medial center of the bottom of the foot to be slightly elevated. It is these arches that compress somewhat during the weight-bearing phase of the human gait, but then act as springs when they rebound to their original shape during the propulsive (push-off) phase of the gait. Medial longitudinal arch Lateral longitudinal arch Transverse arch © Body Scientific International Figure 5.33 Arches of the foot, inferior view. SECTION 5.4 REVIEW Mini-Glossary appendicular skeleton collective term for the bones of the body’s appendages the arms and legs calcaneus the largest of the tarsal bones referred to as the heel bone carpal bones bones of the wrist clavicle a doubly curved long bone that forms part of the shoulder girdle also known as the collarbone false pelvis the bony region of the pelvis that is located superior to the pelvic inlet femur thigh bone fibula bone of the lower leg that does not bear weight humerus major bone of the upper arm lower extremity the hips, legs, and feet metacarpal bones the five interior bones of the hand that connect the carpals in the wrist to the phalanges in the fingers metatarsal bones the small bones of the ankle patella kneecap pectoral girdle the bones surrounding the shoulder, including the clavicle and scapula pelvis collective term for the bones of the pelvic girdle and the coccyx at the base of the spine phalanges bones of the fingers radius the smaller of the two bones in the forearm rotates around the ulna scapula shoulder blade shoulder complex all of the joints surrounding the shoulder, including the acromioclavicular, sternoclavicular, and glenohumeral joints tarsal bones bones of the ankle tibia the major weight-bearing bone of the lower leg true pelvis the region of the pelvis immediately surrounding the pelvic inlet ulna larger bone of the lower arm upper extremity the shoulders, arms, and hands Review Questions 1. Explain how the bones of the pectoral girdle, along with various muscles and joints, allow movement in many different directions. 2. Which bone of the forearm is larger and stronger than the other? 3. Why is the pelvis of a female wider than the pelvis of a male? 4. Which bone of the lower leg is the stronger bone that bears most of the weight of the body above it? 5. Functionally, why does the pectoral girdle have much more range of motion than the pelvic girdle? 6. Why are there two bones in the forearm rather than just one? 7. Why would you not be able to walk properly if you had a fracture in one of the metatarsals or phalanges?