28 terms

PCOM Anatomy 1: Set II for Quiz 2 - Bones & Joints

What is the weight bearing structure in compact bone?
What is the structure of the lamella?
Concentric rings mainly composed of collagen
What connects the blood and nerve supply in the periosteum to the Haversian canal?
Volkmann's canals
Where are the osteocytes contained?
What connects the lacunae?
What is the main microscopic structural element of spongy bone?
Trabeculae - "little beams"
What is the structural function of trabeculae?
They align themselves against lines of stress to resist stress
What are the four organic components of bone?
osteoblasts, osteoclasts, osteocytes, and osteoid
What is the unmineralized bone matrix called?
What are the inorganic components of bone?
mineral salts, mainly calcium phosphates
What is the main function of the inorganic components of bone?
hardness and resistance to compression
What are the two types of bone marrow?
red marrow (hematopoeitic) and yellow marrow
Where is red marrow found?
Between the trabeculae of spongy bone
Where is yellow marrow found?
In the medullary canal of long bone
What is the inner layer of the periosteum?
the osteogenic layer
What are nutrient foramina?
The path by which the periosteum is supplied with nerve fibers, blood and lymph vessels
What is the outer layer of the periosteum?
a fibrous layer of dense connective tissue
What are the four classifications of bone shape?
flat, long, short, irregular
Describe flat bones
thin, flattened and a bit curved
Describe long bones
longer than they are wide
Describe short bones
cube shaped; bones that form between tendons
Describe irregular bones
bones with complicated shapes
What is the blood supply of long bones?
diaphyseal nutrient artery; metaphyseal and epiphysial arteries; periosteal arteries
What is the blood supply of irregular, short, and flat bones?
periosteal arteries and nutrient arteries feeding the medullary bone
What is bone homeostasis?
The process by which Ca is stored and removed for use from bones
What is the hormonal mechanism for the storage of Ca?
When Ca increases in the blood, the thyroid produces calcitonin to stimulate calcium salt deposits
What is the hormonal mechanism for the resorption of Ca?
When Ca falls in the blood, the parathyroid produces PTH which signals the osteoclasts to breakdown the bone matrix, releasing CA into the blood
Where is red marrow found?
in the diploe of flat bones and the head of the femur and humerus in adults