DEXA Anatomy & Physiology of Bone Structure

Question 1

Which bone cells are responsible for bone formation?

Accepted Answer

Osteoblasts

Answer

Osteoblasts are specialized cells responsible for synthesizing and depositing new bone matrix, a process known as bone formation or ossification. They play a crucial role in bone growth, repair, and remodeling by laying down collagen and other proteins that become mineralized. This activity is essential for maintaining bone strength and integrity.

Question 2

What is the main mineral found in bone?

Accepted Answer

Calcium phosphate

Answer

The primary mineral component of bone is calcium phosphate, specifically in the form of hydroxyapatite crystals. These crystals provide bone with its rigidity and strength, making it capable of supporting the body and protecting organs. Calcium phosphate is vital for bone health and is the target mineral measured in DEXA scans.

Question 3

Where is spongy bone found?

Accepted Answer

At the ends of long bones

Answer

Spongy bone, also known as cancellous or trabecular bone, is characterized by its porous, lattice-like structure. It is primarily found at the ends of long bones (epiphyses) and within the interior of flat and irregular bones. This structure provides strength without excessive weight and houses red bone marrow.

Question 4

Which hormone regulates calcium levels in bone?

Accepted Answer

Parathyroid hormone

Answer

Parathyroid hormone (PTH) is a crucial regulator of calcium levels in the blood and bone. When blood calcium levels are low, PTH is released, stimulating osteoclasts to resorb bone and release calcium into the bloodstream. It also promotes calcium reabsorption in the kidneys and vitamin D activation, which aids calcium absorption from the gut.

Question 5

What is the function of osteoclasts?

Accepted Answer

Bone resorption

Answer

Osteoclasts are large, multinucleated cells responsible for bone resorption, the process of breaking down bone tissue. They secrete acids and enzymes that dissolve the mineral matrix and organic components of bone. This process is essential for bone remodeling, repair, and the release of calcium into the bloodstream.

(DEXA) DEXA Bone Density Scan Certification Practice Test

(DEXA) DEXA Bone Density Scan Certification Practice Test

DEXA Anatomy & Physiology of Bone Structure