Describe in proper sequence the events of endochondral ossification in a long bone.

Video transcript

Welcome back, everyone. Let's take a look at our next question. Which of the following is a process of bone formation that takes place in long bones during embryonic development and growth. Choice, a intramembranous intramembranous ossification. Choice B, endochondral ossification, C periosteal ossification or D heterotopic ossification. So we noticed that all of our answer choices have ossification as part of the name. So no help there. Uh So we're thinking about long bones during embryonic development. And that process is choice b endochondral ossification. And that's the process by which you have a cartilaginous model for the developing bone. And the cartilage is gradually replaced by bone tissue. You have a little help from your name here. And that when you look at this part of the first part of the name chondral, think of like chondrocytes or cells that produce cartilage. So that can maybe help point us in the cartilage direction and help us remember that this is the process for long bones. When we look at our other answer, choices, choice, a intramembranous. So this is the process of the formation of flat bones in embryonic development. And in intramembranous sas, there's no carilla model they form directly from connective tissue. So no intermediate there with a model uh that includes the flat bones of the skull, facial bones and clavicles are examples of bones that are formed in that way, but not the answer we're looking for. So we'll cross that out in choice. C periosteal ossification. This would be formation of the bone tissue on the outer surface of the bones. So new bone tissue on bone, outer surface and this is an important part of bone remodeling and bone repair and can be in response to mechanical stress but not what we're looking for. So, cross that out and finally, we've got choice d hetero tropic ossification and this is actually when you have formation of bone in abnormal locations. So this can be places like muscles or tendons and it can be do to causes like injury or surgery and can lead to joint stiffness. So this is an abnormal process, not part of normal development and not what we're looking for. So again, the process of bone formation that takes place in long bones during embryonic development and growth is choice b, endochondral ossification. See you in the next video.