EK Bio Ch. 8 question from EK 1001

[dougkaye]

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Havin another EK 1001 Bio "WTF" moment 🙂
#868: which of the following wells are found in woven (immature) bone?
a. fibroblasts
b. osteoclasts
c. keratinotyes
d. chondrocytes

I immediately dismissed c,d but chose a over b. I take issue with EK's logic. First of all, osteoclasts would be more associated with MATURE bone. As EK says in their explantion, osteocytes are mature osteoblasts that have been trapped in bone. They are incorrect in saying that fibroblasts synthesize muscle tissue. Fibroblast is general term for any fiber-secreting cell INCLUDING osteoblasts which are more associated with immature bone (deposition) versus osteocytes (post-deposition, mature bone). Fibroblasts don't really synthesize muscle tissue - just the parts of muscle tissue that are made of connective tissue such as the fascicles, etc. So they're really out on a limb on this question in my opinion.

What do y'all think? In general, I am finding EK Bio 1001 a good review tool but pretty frustrating in terms of how carefully it's been edited by someone who would have the qualification to teach a college-level bio course.

What is on wiki is what i learned in bio class: "
Osteoblasts (from the Greek words for "bone" and "germ" or embryonic) are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are sophisticated fibroblasts that express all genes that fibroblasts express, with the addition of the genes for bone sialoprotein and osteocalcin.[1]?"

 

[jphwki82]

Havin another EK 1001 Bio "WTF" moment 🙂
#868: which of the following wells are found in woven (immature) bone?
a. fibroblasts
b. osteoclasts
c. keratinotyes
d. chondrocytes

I immediately dismissed c,d but chose a over b. I take issue with EK's logic. First of all, osteoclasts would be more associated with MATURE bone. As EK says in their explantion, osteocytes are mature osteoblasts that have been trapped in bone. They are incorrect in saying that fibroblasts synthesize muscle tissue. Fibroblast is general term for any fiber-secreting cell INCLUDING osteoblasts which are more associated with immature bone (deposition) versus osteocytes (post-deposition, mature bone). Fibroblasts don't really synthesize muscle tissue - just the parts of muscle tissue that are made of connective tissue such as the fascicles, etc. So they're really out on a limb on this question in my opinion.

What do y'all think? In general, I am finding EK Bio 1001 a good review tool but pretty frustrating in terms of how carefully it's been edited by someone who would have the qualification to teach a college-level bio course.

What is on wiki is what i learned in bio class: "
Osteoblasts (from the Greek words for "bone" and "germ" or embryonic) are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are sophisticated fibroblasts that express all genes that fibroblasts express, with the addition of the genes for bone sialoprotein and osteocalcin.[1]?"

They are correct about osteoclasts being involved with immature bone. Woven bone is the first compact bone synthesized during fetal development and bone repair. It will be remodeled and replaced by secondary (lamellar) bone, with the exception of a few select areas. During bone remodeling, both osteoblasts and osteoclasts will be involved. Osteoclasts will reabsorb the bone matrix and release it into the CT capillaries. Osteoblasts will be stimulated to differentiate to start synthesizing new bone, generally speaking. Any remodeling will involve osteoclasts, and primary bone requires remodeling to form mature bone.

 

[Le Boudin]

FYI in the newer edition of the book the answer choice was changed to
b. osteoCYTES

I chose a. fibroblasts, and I still disagree with BR's explanation. OsteoCYTES are "mature osteoblasts trapped in bone" according to their own answer explanation--thus association with MATURE BONE, not IMMATURE BONE.

WTF?