18
votes
Accepted
What is this bone from?
Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view ...
- 28.5k
15
votes
Accepted
Human spine: Is the coccyx really fused?
The wikipedia article links to two papers. The first article has data for 120 pain-free and 51 affected patients with data on the number of coccygeal segments in each. We can back-calculate a ...
- 12.2k
12
votes
Accepted
Can you bleed from your bones?
Yes, bones too bleed if they get damaged (break or bruise). This is because bones are highly vascularised organs and breaking of bones will indeed rupture the blood vessels causing bleeding. Main ...
- 4,776
11
votes
Found this under a rock at the beach, removed it carefully and couldn't find any other bones, must be a marine mammal of some sort
A reasonable match for many features, bearing in mind the incompleteness of the skull is that of the South African Fur Seal (AKA. brown fur seal, Australian fur seal).:
Carolyn Stewardson, Tania ...
- 1,556
8
votes
Accepted
Stretching and compressing bones
Citing your source would help to answer.
In order to test an elastic modulus, you need to apply some non-zero strain. If the strain is infinitesimal, then compression and stretch modulus will be ...
8
votes
Why does cracking a joint make noise?
A paper was just published that explains this phenomenon in PLOS One, found here. It looks like the sound is caused by the formation of a gas cavity in synovial fluid of the joints. They do mention ...
- 1,816
8
votes
Accepted
Identify these hinged barbed bones
I think it is part of a Australian trigger fish skull. check the pictures below, unfortunately someone sawed off most of the spine on the skull photo, but you can see the base of it, it is probably ...
- 13.8k
8
votes
Identifying a lone bone found newar Rowena Crest, Oregon (USA)
My guess is that it's a relatively young cow humerus. The strongly grooved trochleas are more characteristic of a humerus than a femur, which usually just has two condyles. The deep pit is where the ...
- 12.2k
7
votes
Accepted
What is head of a bone?
Here is a head and a neck:
Anatomy is fairly straightforward. regarding individual long bones, "heads" are curved ends of bones distal to a narrowing called a neck of a bone. Take the radius:
See ...
- 24.5k
6
votes
Human spine: Is the coccyx really fused?
lets answer in order.
Is the coccyx a single bone or multiple bones?
answer yes, A bone is not a concrete definition and can be used to describe the number of elements or the number of ...
- 13.8k
5
votes
Can skeletal morphology change in adults?
Bone never stops changing.
Your bones are constantly being broken down and reformed on a microscopic level. Your bones are done growing at a certain point but they continue to be reshaped. Remember ...
- 13.8k
5
votes
Accepted
Do Osteichthyes fishes have any cartilage?
Yes, Osteichthyes do have cartilage. For example, Ancient origin of lubricated joints in bony vertebrates shows images of cartilaginous tissue in the joints of several bony fish. More generally, ...
- 14.1k
5
votes
Do patella bones form in people born with the inability to walk?
In mice, patella would form, but not separate from femur.
On the development of the patella:
Previous studies have suggested a central role for mechanical load in
the initiation of sesamoid ...
- 1,443
4
votes
Accepted
Human bone density and Brown Bear bone density?
The word density in the medical term bone density is used to quantify only the mineral content of the bone (bone mineral). It's not intended to describe the total mass density of the bone like we are ...
- 984
4
votes
Is there any way bicondylar/bigonial, bizygomatic or bitemporal breadth can change in adults?
Acromegaly (pituitary gigantism) is a disease that causes enlargement of the bones of the face. There is interest in computerizing facial measurements to catch subtle enlargements and prompt testing ...
- 2,954
3
votes
Identify a lone bone (jaw including teeth) found on a beach at Trouville-sur-Mer (France) in 2018
It would be great to have a scale bar in the photo, so that the size would be easier to determine. However, by the shape of the teeth, I will propose that it is the back half of the jaw of a pig. Here ...
- 12.2k
3
votes
How does cartilage become bone?
The process is called endochondral ossification.
It is important to point out that not all bone is derived from cartilage. For example, when a bone is fractured and is healing, the new bone does not ...
- 2,472
3
votes
Accepted
What purpose do the opening(s) serve in diapsid and synapsid skulls?
It is believed that originally the holes evolved to give the jaw muscles a place to expand into as they contract. They evolved as the the otherwise larger jaw muscles are trapped between the bones ...
- 13.8k
3
votes
Why do we have the tibia and fibula (a 2nd bone) in the lower leg?
It does function in the rotation and stabilization of the foot, but that is not why we have it, even species in which it serves no function still have it. A bone does not necessarily have to have a ...
- 13.8k
3
votes
Accepted
How large is the variability in human bone thickness, and is "big boned" a real thing or not?
Since the argument with my girlfriend was finished days after this was posted(sadly we were waiting for this but it took so long, we posted this question to have an answer right away) I'll just post ...
- 167
3
votes
Accepted
Bolyerine Snakes maxillary bone, split?
If you look at Fig. 2 in the paper, the bottom jaw has the split maxillary bone. Do you see how it says "MX" with two lines, instead of "MX" with 1 line on the top skull from Fig. 2? Each of those ...
- 46
3
votes
Mean and standard deviation of human bone density?
Interesting question that I'd not considered before.
Bone density is commonly measured by assessing the bone mineral density (BMD) using dual-energy x-ray absorptiometry (DMA), literally the g/cm2 of ...
- 6,189
3
votes
At what temperature do human bones disintegrate?
Boiling point of hydroxyapatite is around 1500°C so you will need this temperature to make bone literally evaporate.
Prolonged exposure to lower temperature (like reference in other answer 220°C) ...
- 141
3
votes
Accepted
Organ and Bone Marrow Transplantation?
As Mowgli pointed out, a bone marrow transplant involves destroying the patient's own immune system with radiation and, essentially, replacing it with a new one from the bone marrow donor. If you did ...
- 345
3
votes
How does coffee cause calcium loss in our body?
Caffeine and coffee do not seem to have any significant adverse effect on calcium metabolism. The supposed mechanisms are inhibition of calcium absorption in the intestine and stimulation of calcium ...
- 8,039
3
votes
What is this fossilized claw found in a Belgian forest?
Looks like the proximal end of a rib of a large mammal (cow, horse, deer). Without information about how large it is, it is not possible to get closer to an identification. It's not a claw and very ...
- 12.2k
2
votes
At what temperature do human bones disintegrate?
While this answer shows that collagen denatures at 220°C under dry heat, it is possible to break down the collagen in bones at much lower temperatures by means of hot hydrolysis.
This hydrolysis can ...
- 9,424
2
votes
At what temperature do human bones disintegrate?
The mechanical properties of bone (like Elastic modulus) are generally dependent on a protein called collagen and its cross links. According to this paper, collagen denatures at temperatures around ...
- 557
2
votes
Can magnetoreception occur in humans?
When we talk about 'can something happen', then I don't think the answer would need a reference.
Of course, humans can attain the ability of magnetoreception, but the main question is What good will ...
2
votes
Accepted
How does bone marrow acts like a valve?
First of all, though bone marrow is not considered a part of lymphatic system because it is not connected to lymph vessels, yet it is the site of production of both B- and T-lymphocytes and is thus ...
Only top scored, non community-wiki answers of a minimum length are eligible