1. Is the fault in the components that perform any physical action?
Answer: No
2. Is the faulty component part of the mechanism’s body?
Answer: Yes
3. Is the faulty component in the structure of the mechanism?
Answer: Yes
4. Does the fault appear in components that provide rigidity to the mechanism?
Answer: Yes
5. Can the faulty component be removed from the mechanism?
Answer: Yes
16) Deer, Cervidae
Deer can be found in the entire world in different environments, except in Australia (ÒDeer Fact SheetÓ). Deer are able to regenerate their antlers every year after they shed their previous antlers.
At first researchers believed that a blastema formed and dedifferentiation of cells took place and now they have found that it is not so. The shedding of the antlers has been linked to the hormonal changes that the male undergoes throughout the year. When he has low testosterone levels the antlers will fall off from the pedicle on the deerÕs head. The antler is made up of bone, cartilage, skin, blood vessels, and nerves, which makes it different from horns. The pedicle must regenerate the antler with pedicle periosteum (PP), which are comparable to stem cells in humans (Li). PP cells will proliferate and differentiate into the cartilage and bone of the antler (Li). As more cells differentiate the antler continues to grow until a certain point, which is currently being studied. It is also currently not clear as to how the skin, blood vessels, and nerves are formed but the PP cells seem to stimulate the differentiation of cells for those specific functions.
“Deer Fact Sheet.” DEER FACT SHEET (n.d.): n. pag. Get Active for Animals. World Animal Foundation, 2014. Web. 23 Nov. 2014.
http://www.worldanimalfoundation.net/f/Deer.pdf
Li, Chunyi. “Deer Antler Regeneration: A Stem Cell-based Epimorphic Process.” Birth Defects Research 96.1 (2012): 51-62.Wiley Online Library. Web. 23 Nov. 2014.
http://onlinelibrary.wiley.com/doi/10.1002/bdrc.21000/abstract
Recent Comments