Physiology of the Osteoclast

The video tutorial explores the roles of osteoblasts, osteocytes, and osteoclasts in bone tissue. It explains the differentiation of osteoblasts from osteoprogenitor cells and their function in bone deposition. The focus then shifts to osteoclasts, which originate from macrophages and are responsible for bone resorption. The video details the structure and function of osteoclasts, including their ruffled border and the enzymes involved in degrading bone tissue. Finally, it discusses the hormonal regulation of osteoclast activity and its impact on blood calcium levels.

What is the primary function of osteoblasts in bone tissue?

• To secrete the matrix that forms bone tissue

• To regulate blood calcium levels

• To transport nutrients to bone cells

• To degrade bone matrix

Which cell type is responsible for bone resorption?

• Osteoclasts

• Osteoblasts

• Osteocytes

• Chondrocytes

From which type of cells do osteoclasts originate?

• Chondrocytes

• Osteoprogenitor cells

• Macrophages

• Fibroblasts

What is the ruffled border of an osteoclast responsible for?

• Secreting bone matrix

• Degrading bone tissue

• Transporting calcium

• Absorbing nutrients

Which enzyme is NOT involved in the degradation of the organic part of bone?

• Tartrate resistant acid phosphatase

• Collagenases

• Cathepsin K

• Matrix metalloproteinases

What role does acid play in the function of osteoclasts?

• It helps in the formation of bone matrix

• It denatures proteins on the bone surface

• It inhibits osteoclast activity

• It transports calcium into the blood

Which hormone increases the activity of osteoclasts?

• Glucagon

• Calcitonin

• Parathyroid hormone (PTH)

• Insulin

What happens to blood calcium levels when osteoclast activity is increased?

• They decrease

• They remain unchanged

• They increase

• They fluctuate randomly

Which hormone is antagonistic to parathyroid hormone in regulating osteoclast activity?

• Thyroid hormone

• Calcitonin

• Growth hormone

• Adrenaline

What is the primary function of osteoclasts in bone tissue?

• To increase bone density

• To decrease bone mineral density

• To transport nutrients

• To secrete bone matrix