Ch. 5 - The Skeletal System: Osseous Tissue and Skeletal Structure Flashcards
Osseous Tissue
Bone, a supporting connective tissue
Periosteum
Membrane that seprates osseous tissue from surrounding tissues
Endosteum
Membrane that lines the surface of the bony tissue that forms the medullary cavity of long bones
Matrix of Bone
Calcium phosphate 2/3 weight of bone (strong but brittle)
Collagen fibers 1/3 weight of bone (weaker but flexible)
Functions of the Skeletal System
- Support
- Storage of Minerals
- Blood Cell Production
- Protection
- Leverage
Osteocytes
Type of bone cell
Mature bone cells that maintain and monitor the protein and mineral content of the surrounding matrix.
Lacunae
Small chambers that osteocytes occupy. Sandwiches between layers of calcified matrix.
Lamellae
Matrix layers that sandwiches lacunae in bone
Canaliculi
Channels that radiate through the bone matrix from lacuna to lacuna and toward free surfaces and adjacent blood vessels
Osteoblasts
A type bone cell
Cells that are cuboidal in shape and found on the inner or outer surfaces of a bone. Produces new bone
Osteoid
Organic component of bone matrix secreted by osteoblasts. It later becomes mineralized through an unknown mechanism
Osteogenesis
A process of production of new bone
Osteoprogenitor Cells
A type of bone cell
Differentiate from mesenchyme and are found on the innermost layer of the periosteum and in the endosteum lining the medullary cavities. Can divide to produce daughter cells that differentiate into osteoblasts.
Osteoclasts
Type of bone cell
Secrete acids through the exocytosis of lysosomes. The acids dissolve the bony matrix and release amino acids and the stored calcium and phosphate.
Osteolysis
Erosion process where acids dissolve the bony matrix. This process increaes the calcium and phosphate concentrations in body fluids
Compact Bone
Relatively dense and solid.
Components: osteon, osteocytes, central canal, concentric lamellae, lacunae
Spongy Bone
Forms an open network of struts and plates. Helps reduce weight of skeleton and makes it easier for muscles to move bones
Components: trabeculae (or spicules)
Osteon
Basic functional unit of mature compact bone
Central Canal
Contains the blood vessels that supply the esteon.
Perforating Canals
Blood vessels in these canals deliver blood to osteons deeper in the bone and service the interior medullary cavity
Periosteum
General structure of a long bone
A dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints. A bone is covered externally by a two-layered periosteum (outer fibrous, inner cellular)
Endosteum
General structure of a long bone
Vascular membrane that lines the inner surface of long bones.
Epiphyses
General structure of a long bone
The end part of a long bone, initially growing separately from the shaft.
Diaphyses
General structure of a long bone
The shaft or central part of a long bone.
Metaphyses
General structure of a long bone
The growing part of a long bone between the diaphysis and the epiphysis
Epiphyseal Plate/Line
General structure of a long bone
A hyaline cartilage plate in the metaphysis at each end of a long bone. The plate is found in children and adolescents; in adults, who have stopped growing, the plate is replaced by an epiphyseal line.
Medullary (Marrow) Cavity
General structure of a long bone
The medullary cavity is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow is stored
Articular Cartilage
General structure of a long bone
Prevents damaging bone-to-bone contact within the joint.
Ossification
Process of replacing other tissues with bone
Calcification
The deposition of calcium salts within a tissue
Intramembranous Ossification
Begins when mesenchymal cells differentiate into osteoblasts within embryonic or fibrous connective tissue
Endochondral Ossification
Begins w/ the formation of a hyaline cartilage model. Uses interstitial (length increase) and appositional growth (diameter increase).
Interstitial Growth
The cartilage model will grow in length by continuous cell division of chondrocytes, which is accompanied by further secretion of extracellular matrix (increases in length).
Appositional Growth
Occurs when the cartilage model also grows in thickness due to the addition of more extracellular matrix on the peripheral cartilage surface, which is accompanied by new chondroblasts that develop from the perichondrium (increases in diameter).
Wolff’s Law
Bones remodel according to the stress they are subjected to
Long Bones
A classification of bone
Long and slender w/ a diaphysis, two metaphyses, two epiphyses, and a medullary (marrow) cavity
Found in upper and lower limbs (e.g., humerus radius, ulna, tibia)
Flat Bones
A classification of bone
Thin, roughly parallel surfaces of compact bone (e.g., the roof of the skull).
Pneumatized Bones
A classification of bone
Bones that are hollow or contain numerous air pockets
Irregular Bones
A classification of bone
Complex shapes w/ short, flat, notched, or ridged surfaces
Short Bones
A classification of bone
External surfaces are covered by compact bone, but the interior contains spongy bone (e.g., the carpal bones [wrist])
Sesamoid Bones
A classification of bone
Usually small, round, and flat (e.g., patella).
Bone Markings
Surface features of bones that yield an abundance of anatomical information.
Process
A bone marking (general elevation and projection)
Any projection or bump
Ramus
A bone marking (general elevation and projection)
An extension of a bone making an angle to the rest of the structure
Trochanter
A bone marking (process formed where tendons or ligaments attach)
A large, rough projection
Tuberosity
A bone marking (processes formed where tendons or ligaments attach)
A rough projection
Tubercle
A bone marking (processes formed where tendons or ligaments attach)
A small rounded projection
Crest
A bone marking (processes formed where tendons or ligaments attach)
A prominent ridge
Line
A bone marking (processes formed where tendons or ligaments attach)
A low ridge
Epicondyle
A bone marking (processes formed where tendons or ligaments attach)
A protuberance above or on the condyle of a long bone
Head
A bone marking (processes formed for articulartion w/ adjacent bones)
The expanded articular end of an epiphysis, often separated from the shaft by a narrower neck
Condyle
A bone marking (processes formed for articulartion w/ adjacent bones)
A mooth, rounded articular process
Facet
A bone marking (processes formed for articulartion w/ adjacent bones)
A small, flat articular surface
Fossa
A bone marking (depresions)
A shallow depression
Sulcus
A bone marking (depresions)
A narrow groove
Foramen (Canal)
A bone marking (openings)
A rounded passageway for blood vessels and/or nerves
Meatus
A bone marking (openings)
A passageway through the substance of a bone
Fissure
A bone marking (openings)
An elongated cleft
Sinus
A bone marking (openings)
A chamber within a bone, nornally filled with air
Components of Skeletal System
Bones, cartilages, ligaments, and other connective tissues that stabilize or interconnect them.
