Topic 4 - Osteology Flashcards
(28 cards)
What do most bones consist of?
Thin compact bone, cancellous bone, and think layer of compact bone.
What are the features of Cancellous bone?
Softer, less dense compared to compact bone.
less vascularization.
Has gaps filled with red marrow (stem cell production).
Contains thin, sharp sub units called trabeculae.
What are the features of compact bone?
Hard and dense.
Comprised of minerals, salts, collagen (from bony matrix).
Comprised of cylindrical sub units called osteons.
- Osteons have Haversian canals.*
- volkmanns canals carry small arteries throughout bone*.
What are some components of the bony matrix.
Osteons
Trabeculae
Haversian Canals
Lamellae
What cells are within the Osteons?
Osteoblasts, Osteocytes and Osteoclasts
What is an Osteoblast?
What is the role of an Osteoblast?
Mononucleate cell from which bone develops
Form new lamellar bone. (Formation)
Promote synthesis of bone, remove calcium from bone.
Activity decreases blood calcium levels.
Where are Osteocytes located?
What is the role of an Osteocyte?
What is an Osteocyte?
They are enclosed within the lacunae, they are osteoblasts trapped within the bone matrix.
Responsible for keeping bones healthy (maintenance).
Maintain connections with surrounding via canaliculi
Star-shaped type of bone cell found in cells of mature bone.
What is the role of Osteoclasts?
Breakdown bone and release calcium into plasma. (Breakdown)
Activity Increases blood calcium level.
Describe structure of Haversian canals
Parallel to surface, found along the long long axis of bone, generally contain one or two capillaries and nerve fibers.
What are Haversian Canals?
Hollow channel in center of osteon, runs parallel to length of bone.
What are Volkmanns canals?
Microscopic structures found in compact bone, they carry small arteries throughout the bone.
What is the perichondrium?
Layer of dense irregular C.T that encases cartilage of developing bone.
What does anastomoses mean?
Joined or run together.
What is the structure of a bone?
Periosteum (Layer of C.T).
Compact bone (Outer shell).
Cancellous bone (layer beneath compact bone).
Medullary cavity (Interior).
Marrow (Inner core).
What is lamellar bone?
Bone, with a regular, parallel alignment of collagen into sheets that is mechanically strong.
What is woven bone?
Bone with an irregular organization of collagen fibers, bone is mechanically weak.
What are the three simple parts of a long bone?
The Epiphysis, Diaphysis and Epiphyseal plate.
What is the Epiphysis?
What does it contain?
End part of long bone.
Contains red marrow, blood cells (vascularized).
What is the Diaphysis?
What does it contain?
The middle part of a long bone.
Contains yellow marrow (contains fat, cartilage, bone) which is less vascularized.
What is the Epiphyseal plate?
What is its function?
It is a hyaline cartilage plate in the metaphysic at each end o a long bone.
Mend fractures, enlarge epiphysis, provide bone strength, lengthen long bone.
What are some examples of long bone?
Femur, Tibia and Fibula.
Humerus, Radius and Ulna.
Clavicles.
Metacarpals, Metarsarls and phalanges.
What are the two types of bone growth?
Membranous osteogenesis
Endochondral osteogenesis
What are the features of Membranous osteogenesis?
Direct.
Appositional growth in thickness.
Involves mesenchymal fibrous tissue (Osteoblasts).
What are the features of Endochondral osteogenesis?
Indirect.
Longitudinal growth.
Hyaline cartilage calcifies.
