health bones skeleton diagram labeled

As an infant develops in-vitro, cartilage slowly hardens into bone forming the axial and appendicular structures. At birth we have close to 300 separate bones that solidify into the 206 in the adult body

  • The skull, or cranium, is made up of 22 separate cranial and facial bones, most of which fuse together at suture lines with age. The eyes, brain, and inner ear are protected by the cranium. The lower jaw bone is the only movable part, connected to the upper jaw at the temporo-mandibular joint
  • The bones of the inner ear, the malleusincus, and stapes, are the smallest of the body
  • The spinal column consists of 33 vertebrae. From top to bottom, seven cervical, twelve thoracic, five lumbar, five sacral, and four coccyx. The individual vertebrae are circular structures that arch around a central opening where the spinal cord is threaded through. They have bony protrusions called ‘processes’ where the vertebrae fit together. The upright posture of the human body is supported by the curved shape of the spinal column: At the C1 vertebrae, the spine is connected to the skull and curves slightly forward to support the cranium. The thoracic vertebrae, located between the shoulders, curve backward making room for the heart, lungs, and other internal organs. The lumbar vertebrae in the lower back then curves forward to balance the torso on top of the legs, and at the fused vertebrae of the sacrum and coccyx the base of the spine curves under
  • The ribs attach at the thoracic vertebrae, curve around to the front of the body where the costal cartilage connects them to the sternum forming the rib cage. There are 12 ribs on each side; the top seven that connect to the sternum are the “true ribs,” the next three connect to the costal cartilage of the upper ribs and are called “false ribs,” and the lowest two “floating ribs” connect only in back at the vertebral column
  • On top of the rib cage, the right and left clavicle, the collar bones, connect to the top of the sternum in front, and to the right and left scapula behind
  • The humerus of the upper arm connects at the scapula and then to the radius and ulna of the lower arm
  • The bones of the wrist and hand are the carpal bones. The metacarpals differentiate into the five fingers, and the phalanges are the finger bones
  • The pelvis is a butterfly shaped structure connected to the base of the spinal column supporting the digestive, reproductive, and excretory organs
  • The strongest bone of the body is the femur, the thigh bone. It connects at the pelvis to form the hip joint and then to the tibia, the shin bone, and the fibula of the lower leg
  • The patella, or kneecap, is a sesamoid bone connected to the knee joint by crisscrossing ligaments at the base of the femur
  • The tarsals are the bones of the ankle and upper foot. The metatarsals differentiate into the five toes and, like the hands, the phalanges are the toe bones