Friday, April 28, 2017

Spine (vertebral column)[edit] A fully grown adult features 26 bones in the spine, whereas a child can have 34. The cervical vertebrae (7) The thoracic vertebrae (12) The lumbar vertebrae (5) The sacral vertebrae (5 at birth, later fused into one) The coccygeal vertebrae (5 at birth, some or all of the bones fuse together but there seems to be a disagreement between researchers as to what the most common number should be. Some say the most common is 1, others say 2 or 3, with 4 being the least likely. It is counted as 1 in this article.[citation needed]) Chest (thorax)[edit] There are usually 25 bones in the chest but sometimes there can be additional cervical ribs in humans. Cervical ribs occur naturally in other animals such as reptiles. The sternum (1) The ribs (24, in 12 pairs) It is important to note that three pairs (the 8th, 9th and 10th), also known as false ribs, are attached to each other. They are also attached to the 7th rib by cartilage and synovial joints. Also two pairs of floating ribs (the 11th and 12th), have no anterior attachment. Cervical ribs are extra ribs that occur in some humans. Skull (cranium)[edit] There are 22 bones in the skull. Including the hyoid and the bones of the middle ear, the head contains 29 bones. The cranial bones (8) The occipital bone The parietal bones (2) The frontal bone The temporal bones (2) The sphenoid bone (sometimes counted as facial) The ethmoid bone (sometimes counted as facial) The facial bones (14) The nasal bones (2) The maxillae (upper jaw) (2) The lacrimal bone (2) The zygomatic bone or cheekbone (2); The palatine bone (2) The inferior nasal concha (2) The vomer The mandible (lower jaw) The hyoid bone (not connected to any other bone) In the middle ears (6) malleus (2) incus (2) stapes (2) Arm[edit] There are a total of 64 bones in the arm. The upper arm bones (6 bones, 3 on each side) The humerus The shoulder (pectoral girdle) The scapula The clavicles The lower arm bones (4 bones, 2 on each side) The ulna The radius The hand (54 bones, 27 in each hand) The carpals scaphoid bone (2) lunate bone (2) triquetral bone (2) pisiform bone (2) trapezium (2) trapezoid bone (2) capitate bone (2) hamate bone (2) The metacarpals (5 × 2 = 10) The phalanges of the hand proximal phalanges (5 × 2 = 10) intermediate phalanges (4 × 2 = 8) distal phalanges (5 × 2 = 10) Pelvis (pelvic girdle)[edit] The hip bone has three regions: ilium, ischium, and pubis (2) The sacrum and the coccyx attach to the two hip bones to form the pelvis, but are more important to the spinal column. For this reason it is omitted from the pelvic girdle. Leg[edit] The femur (2) The patella or kneecap (2) The tibia (2) The fibula (2) The foot (52 bones in total, 26 per foot) The tarsus calcaneus or heel bone (2) talus (2) navicular bone (2) medial cuneiform bone (2) intermediate cuneiform bone (2) lateral cuneiform bone (2) cuboid bone (2) The metatarsals (10) The phalanges of the foot proximal phalanges (5 × 2 = 10) intermediate phalanges (4 x 2 = 8) distal phalanges (5 x 2 = 10) Sesamoid bones[edit] Patella Pisiform bone Fabella Cyamella (bone) Sesamoids in the first and second metacarpal bones Sesamoids in the first metatarsal bone Inconsistent sesamoids in other fingers and toes Lenticular process of the incus Rider's bone Inconsistent sesamoids in the legs, arms or buttocks References[edit] The 206 Bones of the Human Body Jump up ^ Mammal Anatomy: An Illustrated G


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