About This Product
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Style: Basic Button Keychain
Set your keys apart with a custom keychain. Create your own or choose from thousands of cute and cool designs. The sturdy clasp keeps your keys together securely and holds up well through daily wear-and-tear.
- Diameter: 2.25"
- Depth: 0.19"
- Weight: 0.25 oz.
- Full-color, full-bleed printing
- Designer Tip: To ensure the highest quality print, please note that this product’s customizable design area measures 2.25" x 2.25". For best results please add 1/16" bleed.
About This Design
Human Skeleton Keychain
The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs and heart. The biggest bone in the body is the femur in the thigh and the smallest is the stapes bone in the middle ear. In an adult, the skeleton comprises around 30-40% of the total body weight, and half of this weight is water. Fused bones include those of the pelvis and the cranium. Not all bones are interconnected directly: there are three bones in each middle ear called the ossicles that articulate only with each other. The hyoid bone, which is located in the neck and serves as the point of attachment for the tongue, does not articulate with any other bones in the body, being supported by muscles and ligaments. Development Early in gestation, a fetus has a cartilaginous skeleton from which the long bones and most other bones gradually form throughout the remaining gestation period and for years after birth in a process called endochondral ossification. The flat bones of the skull and the clavicles are formed from connective tissue in a process known as intramembranous ossification, and ossification of the mandible occurs in the fibrous membrane covering the outer surfaces of Meckel's cartilages. At birth, a newborn baby has over 300 bones, whereas on average an adult human has 206 bones (these numbers can vary slightly from individual to individual). The difference comes from a number of small bones that fuse together during growth, such as the sacrum and coccyx of the vertebral column. Organization See also: List of bones of the human skeleton There are over 206 bones in the adult human skeleton, a number which varies between individuals and with age - newborn babies have over 270 bones some of which fuse together into a longitudinal axis, the axial skeleton, to which the appendicular skeleton is attached. Axial skeleton Axial skeleton The axial skeleton (80 bones) is formed by the Vertebral column (26), the Rib cage (12 pairs of ribs and the sternum), and the skull (22 bones and 7 associated bones). The axial skeleton transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the hip joints, and is therefore responsible for the upright position of the human body. Most of the body weight is located in back of the spinal column which therefore have the erectors spinae muscles and a large amount of ligaments attached to it resulting in the curved shape of the spine. The 366 skeletal muscles acting on the axial skeleton position the spine, allowing for big movements in the thoracic cage for breathing, and the head. Conclusive research cited by the American Society for Bone Mineral Research (ASBMR) demonstrates that weight-bearing exercise stimulates bone growth. Only the parts of the skeleton that are directly affected by the exercise will benefit. Non weight-bearing activity, including swimming and cycling, has no effect on bone growth. Appendicular skeleton Appendicular skeleton The appendicular skeleton (126 bones) is formed by the pectoral girdles (4), the upper limbs (60), the pelvic girdle (2), and the lower limbs (60). Their functions are to make locomotion possible and to protect the major organs of locomotion, digestion, excretion, and reproduction. Function The skeleton serves 6 major functions. Support The skeleton provides the framework which supports the body and maintains its shape. The pelvis and associated ligaments and muscles provide a floor for the pelvic structures. Without the ribs, costal cartilages, and the intercostal muscles the heart would collapse. Movement The joints between bones permit movement, some allowing a wider range of movement than others, e.g. the ball and socket joint allows a greater range of movement than the pivot joint at the neck. Movement is powered by skeletal muscles, which are attached to the skeleton at various sites on bones. Muscles, bones, and joints provide the principal mechanics for movement, all coordinated by the nervous system. Protection The skeleton protects many vital organs: • The skull protects the brain, the eyes, and the middle and inner ears. • The vertebrae protects the spinal cord. • The rib cage, spine, and sternum protect the lungs, heart and major blood vessels. • The clavicle and scapula protect the shoulder. • The ilium and spine protect the digestive and urogenital systems and the hip. • The patella and the ulna protect the knee and the elbow respectively. • The carpals and tarsals protect the wrist and ankle respectively. Blood cell production The skeleton is the site of haematopoiesis, which takes place in yellow bone marrow. Marrow is found in the center of long bones. Storage Bone matrix can store calcium and is involved in calcium metabolism, and bone marrow can store iron in ferritin and is involved in iron metabolism. However, bones are not entirely made of calcium,but a mixture of chondroitin sulfate and hydroxyapatite, the latter making up 70% of a bone. Endocrine regulation Bone cells release a hormone called osteocalcin, which contributes to the regulation of blood sugar (glucose) and fat deposition. Osteocalcin increases both the insulin secretion and sensitivity, in addition to boosting the number of insulin-producing cells and reducing stores of fat. Gender-based differences An articulated human skeleton, as used in biology education There are many differences between the male and female human skeletons. Most prominent is the difference in the pelvis, owing to characteristics required for the processes of childbirth. The shape of a female pelvis is flatter, more rounded and proportionally larger to allow the head of a fetus to pass. Also, the coccyx of a female's pelvis is oriented more inferiorly whereas the man's coccyx is usually oriented more anteriorly. This difference allows more room for a developing fetus. Men tend to have slightly thicker and longer limbs and digit bones (phalanges), while women tend to have narrower rib cages, smaller teeth, less angular mandibles, less pronounced cranial features such as the brow ridges and external occipital protuberance (the small bump at the back of the skull), and the carrying angle of the forearm is more pronounced in females. Females also tend to have more rounded shoulder blades. Disorders Anatomy (from the Greek ἀνατομία anatomia, from ἀνατέμνειν ana: separate, apart from, and temnein, to cut up, cut open) is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy (zootomy) and plant anatomy (phytotomy). In some of its facets anatomy is closely related to embryology, comparative anatomy and comparative embryology, through common roots in evolution. Anatomy is subdivided into gross anatomy (or macroscopic anatomy) and microscopic anatomy. Gross anatomy (also called topographical anatomy, regional anatomy, or anthropotomy) is the study of anatomical structures that can be seen by unaided vision with the naked eye. Microscopic anatomy is the study of minute anatomical structures assisted with microscopes, which includes histology (the study of the organization of tissues), and cytology (the study of cells). The history of anatomy has been characterized, over time, by a continually developing understanding of the functions of organs and structures in the body. Methods have also improved dramatically, advancing from examination of animals through dissection of cadavers (dead human bodies) to technologically complex techniques developed in the 20th century including X-ray, ultrasound, and MRI imaging. Anatomy should not be confused with anatomical pathology (also called morbid anatomy or histopathology), which is the study of the gross and microscopic appearances of diseased organs. • Superficial anatomy Superficial anatomy or surface anatomy is important in anatomy being the study of anatomical landmarks that can be readily seen from the contours or the surface of the body. With knowledge of superficial anatomy, physicians or veterinary surgeons gauge the position and anatomy of the associated deeper structures. Superficial is a directional term that indicates one structure is located more externally than another, or closer to the surface of the body. Human anatomy Para-sagittal MRI scan of the head An X-ray of a human chest. Human heart and lungs, from an older edition of Gray's Anatomy. Human anatomy, including gross human anatomy and histology, is primarily the scientific study of the morphology of the adult human body. Generally, students of certain biological sciences, paramedics, prosthetists and orthotists, physiotherapists, occupational therapy, nurses, and medical students learn gross anatomy and microscopic anatomy from anatomical models, skeletons, textbooks, diagrams, photographs, lectures and tutorials. The study of microscopic anatomy (or histology) can be aided by practical experience examining histological preparations (or slides) under a microscope; and in addition, medical students generally also learn gross anatomy with practical experience of dissection and inspection of cadavers (dead human bodies). Human anatomy, physiology and biochemistry are complementary basic medical sciences, which are generally taught to medical students in their first year at medical school. Human anatomy can be taught regionally or systemically; that is, respectively, studying anatomy by bodily regions such as the head and chest, or studying by specific systems, such as the nervous or respiratory systems. The major anatomy textbook, Gray's Anatomy, has recently been reorganized from a systems format to a regional format, in line with modern teaching methods. A thorough working knowledge of anatomy is required by all medical doctors, especially surgeons, and doctors working in some diagnostic specialities, such as histopathology and radiology. Academic human anatomists are usually employed by universities, medical schools or teaching hospitals. They are often involved in teaching anatomy, and research into certain systems, organs, tissues or cells. her branches • Comparative anatomy relates to the comparison of anatomical structures (both gross and microscopic) in different animals. • Anthropological anatomy or physical anthropology relates to the comparison of the anatomy of different races of humans. • Artistic anatomy relates to anatomic studies for artistic reasons. • American Association of Anatomists • Anatomical terms of location • Body plan • Charaka, referred to as the Father of Anatomy. • Foundational Model of Anatomy • History of anatomy • Important publications in anatomy • List of anatomical topics • Superficial anatomy • Cat anatomy • Fish anatomy • Bird anatomy • Spider anatomy Human anatomy: • List of human anatomical features • List of human anatomical parts named after people • Acland's Video Atlas of Human Anatomy • Physiology
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Product ID: 146870319610293246
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