Arches of the foot Arches of the foot The arches of the foot, formed by the tarsal and metatarsal bones, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight. They are categorized as longitudinal and transverse arches. The longitudinal arches of the foot can be divided into medial and lateral arches. The medial arch is higher than the lateral longitudinal arch. It is made up by the calcaneus, the talus, the navicular, the three cuneiforms (medial, intermediate, and lateral), and the first, second, and third metatarsals. Its summit is at
Effect of spaceflight on the human body on the bones, there is a rapid increase in bone loss, from 3% cortical bone loss per decade to about 1% every month the body is exposed to microgravity, for an otherwise healthy adult. The rapid change in bone density is dramatic, making bones frail and resulting in symptoms which resemble those of osteoporosis. On Earth, the bones are constantly being shed and regenerated through a well-balanced system which involves signaling of osteoblasts and osteoclasts. These systems are coupled, so that whenever bone is broken down, newly formed layers take its place—neither should happen without the other, in a healthy