Cortical and cancellous bone in humans and African apes
- 页数：164 p. :
- 第一责任说明：Charles Andrew Kunos.
- 分类号：a590
MARC全文
62h0020739 20140522143737.0 cr un||||||||| 101009s2003 xx ||||f|||d||||||||eng | CNY371.35 (UnM)AAI3107700 UnM UnM NGL a590 Kunos, Charles Andrew. Cortical and cancellous bone in humans and African apes [electronic resource] : implications for the evolution of bipedality (Pan troglodytes, Gorilla gorilla) / Charles Andrew Kunos. 164 p. : digital, PDF file. Source: Dissertation Abstracts International, Volume: 64-10, Section: A, page: 3745. ; Adviser: Bruce Latimer. Thesis (Ph.D.) -- Case Western Reserve University (Health Sciences), 2003. Among terrestrial mammals, only humans engage in bipedality. Also, humans have significantly altered the distribution of metaphyseal bone in the distal tibia. These observations suggest that our bipedal gait and our unusual skeletal anatomy are mechanically related. This thesis was designed to test the hypothesis that cortical and cancellous bone distributions are different among humans, Pan troglodytes, and Gorilla gorilla for the purpose of attenuating locomotor loads.;When compared, humans have relatively larger volumes of metaphyseal bone in the distal tibia (p < 0.001) than either Pan or Gorilla. Rather than the thick metaphyseal cortical bone found in Pan or Gorilla, human distal tibiae have a thin metaphyseal cortex (p < 0.001) making the ends of their long bones less stiff. Humans also have an enlarged volume of cancellous bone within the metaphysis as compared to Pan and Gorilla (p < 0.001). Such an adaptation of bone form is advantageous in that cancellous bone elastically assumes, stores, and dissipates imposed mechanical loads. Moreover, human cancellous bone trabeculae have a thinner caliber (p < 0.001) than Pan or Gorilla making human trabeculae more likely to bend elastically and to dissipate mechanical loads.;Though there are differences in skeletal anatomy among humans, Pan, and Gorilla, there are not significant difference in the material properties of bone. Human, Pan, and Gorilla distal tibiae do not show differences in the degree of cortical (p = 0.21) or cancellous (p = 0.051) bone mineralization. Likewise, the apparent density of cortical (p = 0.63) and cancellous (p = 0.17) bone is not different among humans, Pan, and Gorilla.;Given the similarity in these material properties, it was found that cancellous bone elastic modulus (p = 0.93) is not different among humans, Pan, and Gorilla. However, a single Gorilla distal tibia does demonstrate a cortical bone elastic modulus (9.8 GPa) less than (p < 0.001) values reported for young adult humans (∼17 GPa). In the context of (a) the small sample size for Gorilla reported in this study, (b) the similarity in cancellous bone elastic modulus for humans, Pan, and Gorilla , and (c) the similarity in human and bovine cortical bone elastic modulus (∼17 GPa), it is likely that Gorilla elastic modulus is similar to moduli reported for humans. To further support this conclusion, human, Pan, and Gorilla whole bone distal tibiae show similar material phase angles on the order of 10 −2 (p = 0.83). Together, these findings suggest that cortical and cancellous bone material properties are similar in humans, Pan , and Gorilla.;Although the material properties are similar, their structural properties are not. The time to peak strain along the metaphysis in humans (0.013 seconds) was significantly longer (p < 0.001) than the time to peak strain in either Pan or Gorilla (0.0004 seconds). This analysis indicates that complex viscoelastic effects of bone found in humans lengthen the time over which loads are applied. These effects lessen the magnitude of mechanical loads in humans.;Therefore, the findings of this thesis support the hypothesis that differences in the quantity and distribution of cortical and cancellous bone within the human metaphysis provides a mechanism to attenuate loads encountered during normal bipedal locomotion. Hominidae. aLatimer, Bruce. aCN bNGL http://pqdt.bjzhongke.com.cn/Detail.aspx?pid=P8Kel7E%2b62I%3d NGL Bs642 rCNY371.35 ; h1 xhbs1003