Term
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Definition
| the process of laying down new bone material by cells called osteoblasts |
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Term
| 2. The Functions of Bones |
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Definition
- support
- protect soft tissues
- act as levers that skeletal muscles use to move body
- store minerals, esp calcium |
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Term
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Definition
- one of two types of osseous tissue that form bones.
- Compared to compact bone (cortical bone), which is the other type of osseous tissue, it has a higher surface area but is less dense, softer, weaker, and less stiff.
- typically occurs at the ends of long bones, proximal to joints and within the interior of vertebrae.
- Cancellous bone is highly vascular and frequently contains red bone marrow where hematopoiesis, the production of blood cells, occurs. |
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Term
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Definition
- one of the two types of osseous tissue that form bones.
- Compact (syn w/ Cortical) bone facilitates bone's main functions: to support the whole body, protect organs, provide levers for movement, and store and release chemical elements, mainly calcium.
- forms the cortex, or outer shell, of most bones. Again, as its name implies, compact bone is much denser than cancellous bone, which is the other type of osseous tissue. Furthermore, it is harder, stronger and stiffer than cancellous bone |
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Definition
| an osteoblast that has become embedded within the bone matrix, occupying a bone lacuna and sending, through the canaliculi, slender cytoplasmic processes that make contact with processes of other osteocytes. |
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Definition
| A cell that secretes the matrix for bone formation. |
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Definition
| a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone (organic dry weight is 90% collagen). This process is known as bone resorption. |
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Definition
| a small space containing an osteocyte in bone or chondrocyte in cartilage. |
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Definition
| tiny channels through the bone, allow osteocytes to contact each other and exchange nutrients and waste |
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Term
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Definition
| – osteon - the cylindrical, column-like structures in compact bones. composed of tiny, tighly compacted cylinders of bone. Each system runs lengthwise to the bone and consists of a multilayered or laminated cylinder composed of concetric layers of ossified bone matrix arranged around a central haversian canal |
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Term
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Definition
| dense fibrous membrane covering the surfaces of bones, consisting of an outer fibrous layer and an inner cellular layer (cambium) |
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Definition
| anastomosing bony spicules in cancellous bone which form a meshwork of intercommunicating spaces that are filled with bone marrow |
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Term
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Definition
- also known as perforating holes,
- microscopic structures found in compact bone.
- They run within the osteons perpendicular to the Haversian canals, interconnecting the latter with each other and the periosteum.
- usually run at obtuse angles to the Haversian canals and contain anastomosing vessels between Haversian capillaries.
- The Volkmann canals also carry small arteries throughout the bone |
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Term
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Definition
| Any of the tiny, interconnecting, longitudinal channels in compact bone tissue around which each haversian system is arranged. contains blood vessels, lymph vessels and nerves that supply the osteocytes. |
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Term
| Endochondral bone formation |
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Definition
when bones start as cartilage and then the cartilage is replaced by bone
The skeleton is formed by hyline cartilage model.
2. The outer layer covering the bone begins to form around the outside.
3. Osteoblast form bone beneath the periosteum. This is called a bone collar and this will become compact bone.
4. At the center of the diaphysis the cartilage cells die creating a cavity.
5. Blood vessels grow into this cavity from the periosteum and deliver osteoblast to the area.
6. Ossification begins around the medullar cavity, this is spongy bone.
7. The same process now occurs in the epiphyses. Steps 4-6.
8. All cartilage is ossified except the areas between the diaphysis and epiphysis. This area is the epiphyseal plate also known as the growth plate. The cartilage cells here continues to divide and ossification occurs at the outer borders allow for longitudinal growth.
9. Cartilage also remains at the ends of the bone, this is the articular cartilage at the joint |
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Term
| intramembranous ossification |
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Definition
- an ossification center appears in the fibrous connective tissue membrane. Selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center,
- bone matrix (osteoid) is secreted w/in the fibrous membrane. Osteoblasts begin to secrete osteoid, which is mineralized w/in a few days. Trapped osteoblasts become osteocytes.
- Woven bone and periosteum form. Accumulating osteoid is laid down between embryonic blood vessels, which form a random network. The results is a network (instead of a lamellae) of trabeculae. Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum.
- bone collar of compact bone forms and red marrow appears. Trabeculae just deep to the periosteum thicken, forming a woven bone collar that is later replaced w mature lamellar bone. Spongy bone (diploe), consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow |
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Term
| Endochondral bone formation |
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Definition
– when bones start as cartilage and then the cartilage is replaced by bone
- formation of bone collar around hyline cartilage model
- cavitation of the hyline cartilage w/in the cartilage model
- invasion of internal cavities by the periosteal bud and spongy bone formation
- formation of the medullary cavity as ossification continue; appearance of secondary ossification centers in the epiphyses in prep for stage 5
- ossification of the epiphyses; when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages |
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Term
| • The external and internal bones of the cranium |
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Definition
External bones of the cranium:
- frontal bones (2)
- interparietal bones (2)
- occipital bone (1)
- parietal bones (2)
- temporal bones (2)
Internal bones of the cranium:
- ethmoid bone (1)
- sphenoid bone (1) |
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Term
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Definition
External bones of the face
- incisive bones (2)
- lacrimal bones (2)
- mandible (1 or 2 )
- maxillary bones (2)
- nasal bones (2)
- zygomatic bones (2)
Internal bones of the face
- palatine bones (2)
- pterygoid bones (2)
- turbinates (4)
- vomer bone (1 |
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Term
| What major benefit does pre-oxygenation have? |
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Definition
- the ultimate source of energy used to produce ATP and CP and keep the whole system operating comes from the catabolism (breakdown) of nutrient molecules)
- 2 main compounds are glucose and oxygen
- muscle fibers can store glucose and oxygen for a rainy day,
- glucose is stored in the fibers in the form of glycogen
- oxygen stored attached to lg protein molecules called myoglobin
- myoglobin can store and release lg quantities of oxygen
- when strenuous muscle contractions begin to deplete the oxygen supply to a muscle fiber, myoglobin can release its stash of oxygen molecules to resupply the fiber.
- as long as the oxygen supply is adequate to keep up with the energy needs of the fiber, the process is known as aerobic (oxygen-consuming) metabolism, and the max amt of energy is extracted from each glucose molecule.
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Term
| Role of ATP and Ca+ in the process of muscle contractions |
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Definition
- during contraction of a muscle, calcium ions bind to troponin. This moves tropomyosin out of the way and uncovers binding sites for myosin on the actin myofilaments
- ADP and phosphate are attached to the myosin head from the previous cycle of movement
- the myosin heads attach to the exposed binding sites on the actin myofilaments to form cross-bridges and the phosphate is released
- energy stored in the head of the myosin myofilament is used to move the head. This causes the actin myofilament to slide past the myosin myofilament. The ADP is released from the myosin head as it moves
- the bond between actin and the myosin head is broken when an ATP molecule binds to the myosin head
- ATP is broken down to ADP and phosphate, releasing energy, which is stored in the myosin head and will be used later for movement. The head of the myosin molecule returns to its upright position and is ready to bind to actin again
- if calcium ions are still present, the entire sequence is repeated |
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