{"id":5610,"date":"2019-07-29T01:29:58","date_gmt":"2019-07-29T01:29:58","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/?post_type=chapter&#038;p=5610"},"modified":"2019-09-25T09:41:29","modified_gmt":"2019-09-25T09:41:29","slug":"human-skeletal-system","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/chapter\/human-skeletal-system\/","title":{"raw":"Human Skeletal System","rendered":"Human Skeletal System"},"content":{"raw":"The skeletal system includes all of the <strong>bones, cartilages, and ligaments<\/strong> of the body that support and give shape to the body and body structures. The\u00a0<strong>skeleton<\/strong>\u00a0consists of the bones of the body. For adults, there are <strong>206 bones<\/strong> in the skeleton. Younger individuals have higher numbers of bones because some bones fuse together during childhood and adolescence to form an adult bone. The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity, and to provide a structure upon which muscles can act to produce movements of the body. The lower portion of the skeleton is specialized for stability during walking or running. In contrast, the upper skeleton has greater mobility and ranges of motion, features that allow you to lift and carry objects or turn your head and trunk.\r\n\r\nIn addition to providing for support and movements of the body, the skeleton has protective and storage functions. It protects the internal organs, including the brain, spinal cord, heart, lungs, and pelvic organs. The bones of the skeleton serve as the primary storage site for important minerals such as calcium and phosphate. The bone marrow found within bones stores fat and houses the blood-cell producing tissue of the body.\r\n\r\nThe skeleton is subdivided into two major divisions\u2014the axial and appendicular.\r\n<h2>The Axial Skeleton<\/h2>\r\nThe skeleton is subdivided into two major divisions\u2014the axial and appendicular. The\u00a0<strong>axial skeleton<\/strong>\u00a0forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back. It serves to protect the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs.\r\n\r\nThe axial skeleton of the adult consists of 80 bones, including the\u00a0<strong>skull<\/strong>, the\u00a0<strong>vertebral column<\/strong>, and the\u00a0<strong>thoracic cage<\/strong>. The skull is formed by 22 bones. Also associated with the head are an additional seven bones, including the\u00a0<strong>hyoid bone<\/strong>\u00a0and the\u00a0<strong>ear ossicles<\/strong>\u00a0(three small bones found in each middle ear). The vertebral column consists of 24 bones, each called a\u00a0<strong>vertebra<\/strong>, plus the\u00a0<strong>sacrum<\/strong>\u00a0and\u00a0<strong>coccyx<\/strong>. The thoracic cage includes the 12 pairs of\u00a0<strong>ribs<\/strong>, and the\u00a0<strong>sternum<\/strong>, the flattened bone of the anterior chest.\r\n<h2>The Appendicular Skeleton<\/h2>\r\nThe\u00a0<strong>appendicular skeleton<\/strong>\u00a0includes all bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult. The bones of the appendicular skeleton are covered in a separate section.\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"921\"]<img class=\"\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181303\/701_Axial_Skeleton-01.jpg\" alt=\"This diagram shows the human skeleton and identifies the major bones. The left panel shows the anterior view (from the front) and the right panel shows the posterior view (from the back).\" width=\"921\" height=\"937\" \/> <strong>Figure 1.\u00a0Axial and Appendicular Skeleton.<\/strong> The axial skeleton supports the head, neck, back, and chest and thus forms the vertical axis of the body. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The appendicular skeleton is made up of all bones of the upper and lower limbs.[\/caption]\r\n\r\n&nbsp;","rendered":"<p>The skeletal system includes all of the <strong>bones, cartilages, and ligaments<\/strong> of the body that support and give shape to the body and body structures. The\u00a0<strong>skeleton<\/strong>\u00a0consists of the bones of the body. For adults, there are <strong>206 bones<\/strong> in the skeleton. Younger individuals have higher numbers of bones because some bones fuse together during childhood and adolescence to form an adult bone. The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity, and to provide a structure upon which muscles can act to produce movements of the body. The lower portion of the skeleton is specialized for stability during walking or running. In contrast, the upper skeleton has greater mobility and ranges of motion, features that allow you to lift and carry objects or turn your head and trunk.<\/p>\n<p>In addition to providing for support and movements of the body, the skeleton has protective and storage functions. It protects the internal organs, including the brain, spinal cord, heart, lungs, and pelvic organs. The bones of the skeleton serve as the primary storage site for important minerals such as calcium and phosphate. The bone marrow found within bones stores fat and houses the blood-cell producing tissue of the body.<\/p>\n<p>The skeleton is subdivided into two major divisions\u2014the axial and appendicular.<\/p>\n<h2>The Axial Skeleton<\/h2>\n<p>The skeleton is subdivided into two major divisions\u2014the axial and appendicular. The\u00a0<strong>axial skeleton<\/strong>\u00a0forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back. It serves to protect the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs.<\/p>\n<p>The axial skeleton of the adult consists of 80 bones, including the\u00a0<strong>skull<\/strong>, the\u00a0<strong>vertebral column<\/strong>, and the\u00a0<strong>thoracic cage<\/strong>. The skull is formed by 22 bones. Also associated with the head are an additional seven bones, including the\u00a0<strong>hyoid bone<\/strong>\u00a0and the\u00a0<strong>ear ossicles<\/strong>\u00a0(three small bones found in each middle ear). The vertebral column consists of 24 bones, each called a\u00a0<strong>vertebra<\/strong>, plus the\u00a0<strong>sacrum<\/strong>\u00a0and\u00a0<strong>coccyx<\/strong>. The thoracic cage includes the 12 pairs of\u00a0<strong>ribs<\/strong>, and the\u00a0<strong>sternum<\/strong>, the flattened bone of the anterior chest.<\/p>\n<h2>The Appendicular Skeleton<\/h2>\n<p>The\u00a0<strong>appendicular skeleton<\/strong>\u00a0includes all bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult. The bones of the appendicular skeleton are covered in a separate section.<\/p>\n<div style=\"width: 931px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181303\/701_Axial_Skeleton-01.jpg\" alt=\"This diagram shows the human skeleton and identifies the major bones. The left panel shows the anterior view (from the front) and the right panel shows the posterior view (from the back).\" width=\"921\" height=\"937\" \/><\/p>\n<p class=\"wp-caption-text\"><strong>Figure 1.\u00a0Axial and Appendicular Skeleton.<\/strong> The axial skeleton supports the head, neck, back, and chest and thus forms the vertical axis of the body. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The appendicular skeleton is made up of all bones of the upper and lower limbs.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n","protected":false},"author":86535,"menu_order":2,"template":"","meta":{"_candela_citation":"[]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-5610","chapter","type-chapter","status-publish","hentry"],"part":1841,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapters\/5610","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/wp\/v2\/users\/86535"}],"version-history":[{"count":9,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapters\/5610\/revisions"}],"predecessor-version":[{"id":6197,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapters\/5610\/revisions\/6197"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/parts\/1841"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapters\/5610\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/wp\/v2\/media?parent=5610"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/pressbooks\/v2\/chapter-type?post=5610"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/wp\/v2\/contributor?post=5610"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-dutchess-ap1\/wp-json\/wp\/v2\/license?post=5610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}