Card Set Information
Chapt 4 @ CCC Doc Majors
What is the order and an explanation of each Bone Cell. (4) & location?
!. Osterprogenitor Cells--basal cells that mature into osteoblasts. Located on the periosteum.
2. Osterblasts--secretes the "osteiod", which is the new cell matrix. The develop into osteocytes as they become trapped into the matrix. Located in the periosteum and the endosteum.
3. Osteocytes--mature bone cells. Maintain the matrix composition.
4. Osteoclasts--cells that dissolved bone matrix(osteolysis) Located in the periosteum and the endosteum, and related to macrophage.
What bone cells are active during growth and remodeling? (1) A lot more of these during growth.
What bone cell maintains the matrix composition?
What bone cell is active during remodeling or to release Ca++ to the blood?
Which bone cell is related to macrophage?
Which bone cell is "mature"?
Which bone cell is a basal cell that matures into osteoblasts?
What are functions of the skeletal system?
1. Support of soft tissue--membranes/fascia anchor organs to bone. Tendons attach muscle to bone.
2. Protection--Bony enclosures surround many organs..brain within skull, heart & lungs within thoracic cage.
3. Movement--joint anatomy allows muscles to pull on bone...motion.
4. Calcuim Reservoir--bone matrix is a storage site for minerals.
5. Blood Cell Production--stem cells in bone marrow are the source of all blood cells
The two cells in osseous tissue?
Osteocytes & osteoblasts
Fibers in osseous tissue?
Collagen, provides flexible strength.
What is the ground substance of osseous tissue made of..?
Hydroxyapatite (proteoglycan mix with minerals) Lots of calcium phosphate + magnesium + flouride.
Mineralized ground substance--provides strength and hardness.
How are the matrix and cells arranged in compact bone? Which are...?
Arranged in osteons. Which are concentric layers of matrix & osteocytes formed around blood vessels.
How are the matrix and cells arranged in spongy bone? Which forms...? What are the open spaces in this area filled with..?
trabecullae...which forms where randomly placed collagen fibers get covered in matrix and cells. Open spaces filled with red bone marrow.
What are the advantages of compact bone?
hard/solid, reist more force in direction of normal movement, verticle strength axis.
What is compact bone located?
Outer coating of all bones, shaft, portion of long bones.
What are some advantages of spongy bone?
Light weight & absorbs shock in ALL directions.
What type of bone absorbs shock in all directions?
What type(s) of bone is found in long bones?
Both types....Compact and Spongy Bone
Where is spongy bone located?
At end portions of long bones, and inside of flat bones (cranial bones, scapula, sternum.
What is the covering of the surface of compact bone called and what is it made of--outer layer and inner layer.
Peristeum...made of Connective Tissue. Outer layer contains collagen fibers that mesh with surrounding c.t.
Inner layer contains osteroprogenitor cells and osteoblasts.
What are the four functions of the periosteum?
1. Isolate bone from surrounding tissue
2. Attaches bone to other joint structures
3. Anchors b.v. & nerves to bone.
4. Involved in repair & growth of bone.
What is the endosteum? When is it active?
Single layer of osteoprogenitor cells that lines narrow cavities and central canals, also covers trabeculae.
Active during growth and repair.
Are bones vascular or avascular..?
How does a bone receives its nutrients?
Through the nutrient artery & vein. Which is an entry/exit way in the middle of the bone for nutrients.
What is ossification?
The conversion of other c.t. into bone.
What is the new matrix without materials yet added? And who is it secreted by..?
osteoid. Secreted by osteoblasts.
What is osteolysis? Who performs this and how..?
The breakdown of bone matrix. The osteoclasts secrete acids & enzymes to dissolve matrix.
Is bone being remodeled? What cells are involved..?
YES,,,bone is frequently being remodeled in order to repair itself, specialize its shape, or growth in size. Both osteoblasts and osteoclasts are involved.