Laboratory 12: Bone structure and classification Flashcards
What does the bone represent?
An organ of the skeletal system.
What is bone composed of?
Osseous tissue, cartilage, dense connective tissue, blood and nervous tissue.
What are the functions of bone?
Support and protect softer tissues, provide points of attachment for muscles, house blood-producing cells, help buffer the blood from extreme fluctuation in pH and to store organic salts.
What does the extracellular matrix surrounding bone contain?
One third organic matter, two thirds inorganic.
What does the organic matter consist of?
Consists of mostly collagen fibers that provide flexibility and strength to withstand tension.
What is the inorganic matter?
Mostly hydroxapatite, complex salt crystals consisting of calcium phosphate.
What are osteogenic stem cells?
They differentiate into osteoblasts that help form bone.
What do osteoblasts isolated in matrix do?
Osteoblasts form osteocytes when isolated in matrix that are vital to bone homeostasis.
What do osteoclasts do?
Dissolve bone to release calcium salts.
How are bones classified in regards to shape?
As long, flat, short, and irregular.
How would you describe long bones?
Long bones are longer then they are wide and have expanded ends.
How would you describe short bones?
Short bones are somewhat cube shaped with similar lengths and widths.
How would you describe sesamoid bones?
A special type of short bones. They are small and embedded within a tendon near joints where compression often occurs.
What type of bone is the patella?
Located in the knee, it is a sesamoid bone.
How would you describe flat bones?
Flat bones have wide surfaces but they can be curved such as those of the cranium
How would you describe irregular bones?
Have numerous shapes and often have articulations with more then one other bone.
What is the supportive tissue during embryonic and fetal development?
Cartilage.
Where is cartilage retained in the adult skeleton?
Articulating surfaces of moveable joints, coastal cartilage connecting the ribs to the sternum and intravertebral discs between the vertebrae.
What does the compact bone contain?
Contains cylinder shaped units called osteons.
What does an osteon contain?
Contains a central canal that includes blood vessels and nerves in living bones and is encircled by concentric lamellae.
Where are the cells or osteocytes?
Located in concentric circles within almond shaped cavities known as lacunae.
What do the cellular processes of osteocytes go through?
Microscopic canaliculi
What do microscopic canaliculi do in regards to compact bone?
Allow for the transport of nutrient and waste substances between the cells and the central canal.
What does the spongy bone contain?
The osteocytes of spongy bone are located within a lattice of boney plates known as trabeculae.
What do the canaliculi do in regards to spongy bone?
Canaliculi allow for diffusion of substances between the cells and the marrow that is positioned between the trabeculae.
What are some examples of long bones?
Femur. humerus, phalanges.
What are some examples of short bones?
Carpals, tarsals, sesamoid bones.
What are some examples of flat bones?
Ribs, scapula, sternum most cranial bones.
What are some examples of irregular bones?
Vertebra, sphenoid
What is an osteon?
Cynlinder shaped unit within compact bone.
What is the central canal?
Located within the osteon, contains blood vessels and nerves.
What is the concentric lamella?
Concentric ring of matrix around central canal of osteon.
What is the interstatial lamella?
Matrix between osteons composed of the remains of old osteons.
What is the circumferential lamella?
Matrix that runs parallel to the surface of the bone.
What is the lacuna?
Small chamber for an osteocyte.
What is the bone extra cellular matrix?
Collagen and calcium phosphate.
What is the canalicus?
Minute tube containing cellular process.
What is the perforating canal?
Runs perpendicular to central canal contains blood vessels and nerves.
What is the epiphysis?
Enlarged ends of a long bone.
What is the epiphyseal plate?
Growth zone of hyaline cartilage.
What is the epiphyseal line?
Site of original epiphyseal plate that has completely ossified.
Where is the articular cartilage
On end of epiphyses.
Where is diaphysis?
Shaft between epiphyses.
Where is the periosteum?
Strong membrane around bone of dense irregular connective tissue. Not at the surface of joints
Where is spongy bone?
Within epiphyses
What is the medullary cavity?
Hollow chamber in diaphysis contains bone marrow.
What is the endosteum?
Thin membrane of reticular connective tissue that lines the medullary cavity.
What is yellow bone marrow?
Occupies medullary cavity and stores adipose tissue.
What is red bone marrow?
Occupies spongy bone in some epiphyses and flat bones and produces blood cells.
