QuestionSBA
QuestionChoice
Osteoclasts are inhibited by calcitonin, a thyroid hormone.

This is released when there is hypercalcaemia so osteoclasts are inhibited to prevent more calcium being released into the bloodstream.

Drugs such as Denosumab which prevents the RANK ligand from binding can stop the activation of the osteoclasts to prevent bone reabsorption.
10005958
c
Inhibits the osteoclasts
QuestionChoice
Osteocytes are found in mature bone matrix and originate from osteoblasts.

They sense various mechanical stress on bone and regulate bone formation and reabsorption in response to this.
10005960
e
Activates the osteocytes
QuestionChoice
Osteoblasts can be activated by osteoclasts in the normal bone modelling cycle.

They can also be upregulated by thyroxine a thyroid hormone and growth hormone.
10005957
b
Activates the osteoblasts
QuestionChoice
Rank ligand is produced by osteoblasts and play a crucial role in the bone remodelling cycle by binding and activating osteoclasts.

Osteoclasts are the cells that degrade bone and initiate normal bone remodelling. Osteoblasts then become activated and form new bone.

In osteoporosis where bone has become weaker, it can be beneficial to inhibit osteoclasts and bone degradation to maintain the bones strength.

Parathyroid also stimulates osteoclasts in response to low calcium in the blood.
10005956
a
Activates the osteoclasts
QuestionChoice
RANK ligand is released by osteoblasts when they proliferate and become active. This activates osteoclasts. Osteoclasts then send signals to osteoblasts to reactivate them

This feedback is crucial in the bone turnover and remodelling.
10005959
d
Inhibits the osteoblasts
Concept
Chapter
2693
4460
Bone remodelling
Topic
154
Musculoskeletal physiology and disease
13738
A 75 year old man has recently been diagnosed with osteoporosis following hormone therapy for his prostate cancer.

He has a review in the bone clinic where they recommend starting Denosumab. This works by blocking the RANK ligand.

What is the role of the RANKL?
a