Renewal of bone Flashcards
What three things is the continual renewal of bone dependent on?
Continual renewal of bone is dependent on physical activity, hormones and diet.
Why is physical activity important for the continual renewal of bone?
When bones are stressed by physical activity they become thicker and stronger (the osteoblasts are stimulated).
When bones are stressed by physical activity they become thicker and stronger (the osteoblasts are stimulated). Where does this happen especially?
This happens especially at the sites where muscles attach to the bone.
How are osteoblasts stimulated?
Physical activity stresses bone and stimulates the osteoblasts making the bone thicker and stronger
What does a lack of stress on bone do to it?
Lack of stress on bones causes them to become thin.
What three hormones affect bone development?
The main hormones affecting bone development are growth hormone, sex hormones and parathormone.
What do Growth hormone and many sex hormones do to the size of bones?
When is this clearly seen?
Growth hormone and many sex hormones increase the size of bones.
This can be seen clearly at puberty when bone mass in the body may increase rapidly.
What does parathormone do to bone?
Parathormone removes calcium from bone.
Why does parathormone remove calcium from bone?
This happens so that the level of calcium in the blood can be raised (a constant level of calcium in the blood is essential for muscles and nerves to work properly).
Why is a constant level of calcium in the blood essential?
a constant level of calcium in the blood is essential for muscles and nerves to work properly
Why is it essential to have sufficient supplies of calcium in your diet?
It is essential to have sufficient supplies of calcium in the diet to replace the calcium lost from bones.
What is osteoporosis?
It is a lack of protein (collagen) material from bone.
It causes bone to be brittle and easily broken.
What is osteomalacia?
a loss of minerals (calcium) from bone due to the lack of vitamin D
