epiphysis
the end of a long bone; proximal or distal depending on where it is attached to the body
diaphysis
the shaft of a long bone
osteocytes
mature bone cells that are found in the web of the bone matrix
endosteum
lines the medullary cavity
hyaline cartilage
Forms much of the fetal skeleton and covers the articular surfaces of long bones
articular cartilage
padding between bones; at the ends of the bones
periosteum
membrane that covers entire bone
spongy bone
type of bone found in the epiphysis; also called cancellous bone
Hematopoeisis
formation of blood cells and occurs in the bone marrow
Compact bone
dense, hard layers of bone tissue that lie underneath the periosteum membrane; contains calcium and phosphorus minerals
Yellow marrow
soft, fatty material found in the medullary cavity of long bones
Osteoblasts
Bone building cells; lay the bone matrix
Erythropoietin (EPO)
hormone secreted by the kidney to stimulate the production of red blood cells by bone marrow
osteoclasts
break down bone to release calcium into the bloodstream
epiphyseal line/plate
between diaphysis and epiphysis of an adult bone. A disc of hyaline cartilage that grows during childhood to lengthen bone.
Red marrow
found in the epiphysis of long bones; where red blood cells are produced.
What are the inorganic and organic components of bone? Which one provides strength and which provides flexibility?
Organic: Collagen fibers- provide flexibility Inorganic: Calcium salts- provide strength
Rickets (osteomalacia of children)
during bone development (usually seen in kids), a lack of calcium and/or vitamin D can lead to a deficiency in calcium in the bone. Osteomalacia is the general term for soft bones.
Purpose of bone marrow
Hematopoiesis - blood cell production (RBC, WBC, Platelets) occurs in the red bone marrow. Also serves as Fat storage (yellow bone marrow)
Hormone that stimulates red blood cell formation
erythropoietin
Hormone that stimulates growth plate to divide and bones to lengthen?
Growth Hormone
What is another name for the growth plate?
epiphyseal plate
What type of tissue is the growth plate made of?
hyaline cartilage
What is the growth plate called after the tissue ossifies (hardens) and lengthens when adult height is reached?
Epiphyseal line
Where do osteoblasts originate?
osteoprogenitor (stem) cells in the periosteum
How do osteoblasts become osteocytes?
osteoblasts get trapped in the bone matrix they secrete (or lay down)
Why do osteoclasts break down bone?
to reabsorb bone and release calcium minerals back in the bloodstream
Name the hormone that stimulates osteoclasts.
Parathyroid hormone (PTH) stimulates osteoclasts to break down bone when the body senses blood calcium levels are too low.
What type of feedback mechanism is the regulation of blood calcium levels?
Negative Feedback
What happens to the bone matrix, over time, if blood calcium levels are always low? Name the condition.
The body will stimulate osteoclasts to break down the compact bone to release calcium leading to osteoporosis (porous bone).
The joint capsule is continuous with which membrane?
periosteum