Bones are constantly undergoing resorption for various reasons. Which of the following cells accomplishes this process?
Which hormone increases osteoclast activity to release more calcium ions into the bloodstream?
The universal loss of mass seen in the skeleton, which begins about the age of 40_______.
reflects incomplete osteon formation and mineralization.
Wolff's law is concerned with _____.
the thickness and shape of a bone being dependent on stresses placed upon it.
Which of the following glands or organs produces hormones that tent to decrease blood calcium levels?
Cartilage grows in two ways, appositional and interstitial. Apositional growth is _____.
the secretion of new matrix against the external face of existing cartilage
Which of the following statements best describes interstitial growth?
Chondrocytes in the lacunae divide and secrete matrix, allowing the cartilage to grow from within.
Lengthwise, long bone growth during infancey and youth is exclusively through ____.
interstitial growth of the epiephyseal plates.
Growth of bones is controlled by a symphony of hormones. Which hormone is important for bone growth during infancy and childhood?
In some cases the epiphyseal plate of the long bones of children closes too early. What might be the cause?
elevated levels of sex hormones
It is thought that remodeling or bone growth is in response to the forces placed on it. Which of the following hypotheses may explain how mechanical forces communicate with cells responding for bone remodeling?
Electrical signals direct the remodeling process
Normal bone formation and growth are dependent on the adequate intake of _____.
calcium, phosphate, and vitamin D
The structrue of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress?
In bone formation, a deficiency of growth hormone will cause _____.
decreased proliferation of the epiphyseal plate cartilage.
Select the correct statement concernng the location of blood-forming tissue.
The sternum(breastbone) is a good source of blood forming tissue.
Cartilage is found in strategic places in the human skeleton. What is responsible for the resilience of cartilage?
high water content
Bones are covered and lined by protective tissue called periosteum. The inner (osteogenic) layer consists primarily of ______.
osteoblasts and osteoclasts
The periosteum is secured to the underlying bone by dense connective tissue called _______.
Perforating (Sharpey's) fibers
The canall that runs through the core of each osteon( the Haversian canal) is the site of _____?
blood vessels and nerve fibers