Term
| What are the functions of the skeletal system? |
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Definition
| support, protection, movement, mineral storage, and blood cell formation |
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Term
| How does the skeletal system aid in support? |
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Definition
| provides support for the entire body |
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Term
| How does the skeletal system aid in protection? |
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Definition
| protection of vital organs: brain |
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Term
| How does the skeletal system aid in movement? |
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Definition
| skeletal muscles pull on bones to create movement |
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Term
| How does the skeletal system aid in mineral storage? |
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Definition
| calcium and phosphate are stored until the body needs it |
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Term
| How does the skeletal system aid in blood cell formation? |
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Definition
| blood cells are formed in bone marrow |
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Term
| What are the two types of tissue found in bone? |
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Definition
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Term
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Definition
| outer portion of bone; smooth, continuous, dense, solid bone |
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Term
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Definition
| inner portion of bone; same material as compact bone, but it's arranged in narrow, irregular bars; not as smooth as compact bone |
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Term
| What are the four types of bones in the body? |
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Definition
| long, short, flat, & irregular |
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Term
| What are the two main parts of a long bone? |
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Definition
| the diaphysis and epiphysis |
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Term
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Definition
| shaft in the middle of the bone, made up of compact bone and a medulary cavity |
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Term
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Definition
| bulbous ends of bones, made up of compact bone surrounding spongy bone |
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Term
| What is the epiphysis made of? |
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Definition
| articular cartilage and an epiphyseal line |
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Term
| What is the purpose of articular cartilage on the epiphysis? |
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Definition
| provides a smooth surface |
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Term
| What is the purpose of the epiphyseal line in the epiphysis? |
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Definition
| marks the spot of an old growth plate |
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Term
| Where are membranes located on the bone? |
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Definition
| inside and outside the bone |
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Term
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Definition
| outside membrane of the bone that contains osteogenic cells |
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Term
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Definition
| the inside membrane of the medulary cavity and the spicula of spongy bone that contains osteogenic cells |
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Term
| What is the structure of short, irregular, and flat bones? |
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Definition
| thin layer of spongy bone, called diploe, sandwiched between two plates of compact bone |
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Term
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Definition
| areas where red blood formation occurs |
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Term
| Where is red marrow found in adults? |
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Definition
| within trabecular cavities of select long bones and diploe of flat bones |
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Term
| Where is red marrow found in infants? |
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Definition
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Term
| What happens to red marrow after childhood? |
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Definition
| area turns to fat and is referred to as yellow marrow |
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Term
| What is the main component of compact bone? |
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Definition
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Term
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Definition
| cylindrical structure that makes up the fundamental part of compact bone |
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Term
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Definition
| thin, concentric layers that form the osteon |
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Term
| What is the haversian canal? |
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Definition
| central canal of osteon filled with blood vessels that allows the bone to be fed and nourished |
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Term
| What is the volkmann canal? |
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Definition
| transverse canal that connects blood vessels in order to bring blood from external to internal bone |
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Term
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Definition
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Term
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Definition
| small cavities that contain the osteocytes |
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Term
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Definition
| small canals that connect lacunae and haversian canals |
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Term
| What does canaliculi allow? |
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Definition
| exchange of material between cells and between cells and blood supply |
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Term
| What is interstitional lamellae? |
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Definition
| layers of bone that lie between osteons in order to fill in the space and maintain the integrity of the bone |
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Term
| What is the circumferential lamellae? |
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Definition
| lie outside the osteon clusters and deep to the periosteum and encircle the entire bone |
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Term
| What are perforated (Sharpey's) fibers? |
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Definition
| extend from the fibrous layer of the periosteum into the bony matrix in order to secure and attach the periosteum to the underlying bone |
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Term
| Where are perforated (Sharpey's) fibers especially found? |
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Definition
| where muscles or ligaments/tendons attach |
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Term
| What is the difference between the structure of spongy and compact bone? |
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Definition
| less rigidly organized; don't contain osteons |
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Term
| What is the structure of spongy bone like? |
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Definition
| trabeculae form sort of a lattice work that gives the appearance of a sponge |
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Term
| What happens when a bone is under more stress? |
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Definition
| trabeculae align along lines of stress, so areas of continued stress develop thicker and more dense spongy bone |
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Term
| What are the types of cells found in bone? |
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Definition
| osteogenic, osteoblast, osteocyte, and osteoclast |
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Term
| What are osteogenic cells? |
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Definition
| stem cells which are mitotic, found in the periosteum or endosteum, that may differentiate into osteoblasts |
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Term
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Definition
| bone forming cells that secrete the bone matrix around where they are located |
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Term
| What is included in the bone matrix? |
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Definition
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Term
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Definition
| mature bone cells that were originally osteoblasts; once the osteoblast has secreted enough matrix, it becomes an osteocyte |
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Term
| What is the role of osteocytes? |
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Definition
| responsible for maintaining the bone matrix; act as stress or stress sensors and respond to mechanical stimuli, such as bone loading or deformation |
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Term
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Definition
| bone "destroying"cells; phagocytes within the bone that destroy the matric |
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Term
| What is the purpose of osteoclasts? |
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Definition
| remodeling or growth, and allow calcium or phosphate to be released into the blood stream |
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Term
| What is different about the osteocytes from the other bone cells? |
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Definition
| it was derived from a different sort of stem cell |
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Term
| What is the ground substance of the bone matrix made of? |
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Definition
| called "osteoid"; proteoglycans, glycoproteins, and hydroxyapatites |
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Term
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Definition
| large proteins and carbohydrate groups found in the osteoid |
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Term
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Definition
| small proteins and carbohydrate groups found in the osteoid |
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Term
| What are the fibers commonly found in the osteoid? |
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Definition
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Term
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Definition
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Term
| How does bone tissue vary from cartilage? |
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Definition
| bone is very dense due to low water content |
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Term
| How does having compact bone peripherally and spongy bone centrally effect function? |
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Definition
| it gives bones strength but leaves them lightweight |
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Term
| How does having calcium phosphates as part of the osteoid effect function? |
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Definition
| bones are important stores calcium and phosphate for cellular functions when they are released |
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Term
| How do osteoclasts, osteoblasts, and osteogenic cells effect function? |
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Definition
| they are important for bone development; osteoclasts break down bone for release of minerals and osteoblasts build up the bone |
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Term
| How does having a marrow cavity effect function? |
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Definition
| it gives a space for bone development (more active in childhood) |
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Term
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Definition
| the development of bone that occurs in the fetus |
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Term
| What are the two types of osteogenesis? |
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Definition
intramembranous (within a membrane)
endochondral (inside cartilage) |
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Term
| Describe the process of intramembranous ossification. |
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Definition
| mesenchyme is the embryonic membrane in which flat bones are typically formed |
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Term
| Describe endochondral ossification. |
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Definition
| ossification that begins with a cartilage template and typically forms long bones |
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Term
| Describe the process of endochondral ossification. |
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Definition
1) cartilage forms precursor tissue and osteoblasts form bone collar
2) central cartilage calcifies and cavities develop
3) periosteal bud invades and brings osteoclasts with
4) diaphysis elongates, medullary cavity forms, and secondary ossification begins at epiphyseal plate
5) epiphyses ossify leaving cartilate within epiphyseal plate |
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Term
| Do long bones continue to grow? |
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Definition
| yes, after the bone has been laid down within the original hyalin cartilage, long bones will continue to grow until you reach puberty |
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Term
| How does long bone grow in length? |
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Definition
-cartilage grows at distal ends and epiphyseal plate
-cartilage is replaced by bone from osteroblasts
-osteoclasts follow behind and carve out the medullary cavity |
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Term
| What is appositional growth? |
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Definition
| the growth of a bone width wise |
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Term
| How does appositional growth work? |
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Definition
| periostial osteoblasts lay down bone and secrete matrix outwards |
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Term
| What are the two ways bone function is regulated? |
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Definition
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Term
| How does growth hormone regulate growth of bones? |
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Definition
| growth hormone secreted by the anterior pituitary gland causes the liver to release a substance called sonatomedins in order to promote cartilage growth at the epiphyseal plate |
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Term
| How does thyroid hormone regulate growth of bones? |
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Definition
| it also works like the growth hormone secreted from the anterior pituitary gland |
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Term
| How do androgenic and estrogenic steroids regulate growth of bones? |
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Definition
| they promote epiphyseal plate closure at puberty |
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Term
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Definition
| lifelong process where mature bone tissue is removed from the skeleton and new bone tissue is formed |
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Term
| How does remodeling happen? |
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Definition
| resorption, during which osteoclasts digest old bone, and formation, when osteoblasts lay down new bone until the resorbed bone is completely replaced |
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Term
| How does the parathyroid hormone regulate bone remodeling? |
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Definition
| it increases osteoclast activity when the blood calcium levels are low |
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Term
| How does calcitonin regulate bone remodeling? |
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Definition
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Term
| What does Wolff's Law state? |
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Definition
| bones grow and remodel in response to mechanical demand |
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Term
| What are the statements of Wolf's Law? |
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Definition
1) assymetrical limb thickness will occur depending on which limb is dominant
2) there will be increased thickness at curved areas in order to prevent buckling
3) spongy bone forms trusses along lines of compression
4) there are enhanced bony projections at sites of muscle attachment |
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