Question

Ellie is a 60-year old postmenopausal sedentary female of Asian descent with a BMI of 18. She is currently taking care of her 82-year old mother who fell and broke her hip. Ellie goes out with friends twice a week for Happy Hour, and usually has no more than 2 drinks. Since living with her mother, she’s cut down on her smoking, but still smokes about 5 cigarettes per day and a little more when she’s out with friends. Ellie’s diet consists of lean protein, fruits and some starchy vegetables, but no dairy as she’s lactose intolerant and has been since she was a child. Explain calcium’s role in bone metabolism and discuss how the two types of bone handle calcium. Include in your answer the hormones responsible for calcium homeostasis and how that affects bone density.

Answer 1

Calcium is a nutrient most commonly associated with the formation and metabolism of bone.Over 99 percent of total body calcium is found as calcium hydroxyapatite in bones and teeth,where it provides hard tissue with its strength.Bones acts as a calcium storage.An important role is plasma calcium homeostasis,the regulation of calcium ions in the blood plasma within narrow limits.

Cortical and trabecular are the two types of bone that handles calcium.

Hormones responsible for calcium homeostasis

Three major hormones PTH ,Vitamin D and calcitonon. These interact to maintain a constant concentration of calcium despite variations intake and excretion.other hormones such as corticosteroids,estrogen,thyroxine,somatotropin, and glucagon may also contribute the maintenance of calcium homeostasis.

The endocrine system is the control center for regulating blood calcium homeostasis. The parathyroid and thyroid glands contain receptors that respond to levels of calcium in the blood. In this feedback system, blood calcium level is the variable, because it changes in response to the environment.It affects bone density by osteoporosis.

Several other hormones play a role in regulating your bone density, including parathyroid hormone and growth hormone. They help orchestrate how well your bones use calcium -- and when to build up and break down bone.