Final Exam 2 Flashcards
What are the two main purposes of bone tissue?
- Mechanical support and protection
- Store and maintain mineral homeostasis
What is cortical bone?
Also known as compact bone, hard, and on the outer tissue
What is cancellous bone?
Also known as trabecular bone, sponge-like tissue
What is subchondral tissue?
Smooth tissue at the ends of bones, which is covered by cartilage
What is cartilage?
Connective tissue present in adults and what most bones develop from in children
How do sharks float?
They have cartilaginous skeletons and do not have bones. They also have a lighter body and low-density oils
What is the periosteum?
tough, thin outer membrane covering the bones
What is beneath the periosteum?
tunnels and canals through which blood and lymphatic vessel run to bring nutrients to bone
What might attach to the periosteum?
muscle, ligaments, and tendons
How are bones classified?
by their shape
What are the classifications of bone shapes?
long, short, flat, and irregular
How many bones are in the human skeleton?
206
How many axial bones are there?
80
How many appendicular bones are there
126
Give some examples of axial bones.
head, facial, hyoid, auditory, trunk, ribs, and sternum
Give some examples of appendicular bones.
arms, shoulders, wrists, hands, legs, hips, ankles, and feet
What is the function of osteoblasts and where are they located?
They form/build new bone tissue and are located within the bone
What is the function of osteoclasts and where are they located?
They absorbs and remove/chew unwanted tissue, they are found in bone marrow
What is the function of osteocytes and where are they located?
They help maintain bones as living tissue and they are found within the bone
What are hematopoietic cells?
Immature cell in bone marrow that can develop into red blood cells (RBCs),white blood cells (WBCs), and platelets
What types of cells are found in bone marrow?
RBCs, WBCs, and platelets
Where are fat cells found?
in bone marrow
What happens to fat cells when someone starves?
They shrink
What is another name for cortical bone?
Compact bone
What is another name for trabecular bone?
spongy bone
What does cortical bone form?
The hard outer layer especially thick in shaft of long bones (e.g. femur)
What percent of bone mass is cortical?
80%
What is trabecular bone?
Spaces in-between trabeculae (lattice-shaped units with bony spicules, filled with bone marrow for hematopoiesis - production of red blood cells)
Where is trabecular bone found?
At the end of long bones, near joints, interior of vertebrae
What are the two types of bony tissue?
cortical (compact) and trabecular (spongy)
Which bony tissue is involved in hematopoiesis?
trabecular
What is the Endosteum?
Membrane that lines the center of the bone (medullary cavity) which contains bone marrow
What is the epiphyseal plate?
The growth plate (physis); a thin layer of cartilage, site of longitudinal and circumferential bone growth
What is the osteon?
The main unit of compact (cortical) bone made of concentric bone layers (lamellae) that surround a long tube. the Haversian canal
What is the lamelle?
Concentric bone layers
True/False: Bone growth and resorption is a continual cycle.
True
True/False: Total bone mass is always changing.
False; total bone mass remains constant
True/False: Bone Deposition and Resorption are normally in Equilibrium (except in growing bones)
True
Describe how osteoblasts lay new bone down?
in successive layers of concentric circles
How long does bone deposition usually last?
months until the tunnel is filled
What is an Osteon?
A new section of bone that was formed by deposition
What stimulates bone turnover and how?
Growth hormone; it increases osteoblast number and function
True/False: Bone turnover is a continual cycle.
True
True/False: Bones shrink when subjected to heavy loads.
False; bones thicken when subjected to heavy loads
True/False: Shape of bone can be rearranged for proper support of mechanical forces by depositing and resorbing bone according to stress patterns
True
How is toughness of bones maintained?
When old bone becomes brittle it undergoes deposition and resorption
Describe bone deposition and adsorption in children vs elderly people.
Bones in children (rapid bone deposition/absorption) are not brittle vs. elderly people with brittle bones (slow deposition/absorption)
True/False: Bone is deposited unproportionate to the compressional load that the bone must carry
False; Bone is deposited in proportion to the compressional load that the bone must carry
True/False: Bones of athletes become much heavier than bones of nonathletes
True
How is osteoblast deposition and calcification stimulated?
By continual physical stress
If you fracture a bone, what is activated?
osteoblasts
