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The pelvis is, in general, different between the human female and male skeleton. [12] [13] Although variations exist and there may be a degree of overlap between typically male or female traits, [12] [13] the pelvis is the most dimorphic bone of the human skeleton and is therefore likely to be accurate when using it to ascertain a person's sex ...
The development of sexual differences begins with the XY sex-determination system that is present in humans, and complex mechanisms are responsible for the development of the phenotypic differences between male and female humans from an undifferentiated zygote. [3]
The ideas of differences between the male and female brains have circulated since the time of Ancient Greek philosophers around 850 BC. In 1854, German anatomist Emil Huschke discovered a size difference in the frontal lobe, where male frontal lobes are 1% larger than those of females. [6]
Phenotypic differences between sexes are evident even in cultured cells from tissues. [132] For example, female muscle-derived stem cells have a better muscle regeneration efficiency than male ones. [133] There are reports of several metabolic differences between male and female cells [134] and they also respond to stress differently. [135]
Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. [1] [2] Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype.
Despite the differences between them, the adult male and female are determined in early development in the 6th week. The gonads and external genitals are derived from the intermediate mesoderm. [7] The three main fetal precursors of the reproductive organs are the Wolffian duct, the Müllerian ducts, and the gonads.
The same perfect vs. lesser relationship is present between male and female reproductive fluids as in Galen's model as male and female genitalia. [31] Laqueur expands this discussion through Avicenna's argument that female seed and menstrual blood are less refined forms of blood, while male seed is a more refined form of blood. [32]
In female cells, random processes of X-inactivation "turn off" the extra X chromosome. As a result, females, but not males, are mosaics. Female cells may express higher levels of some genes. [29] [30] [31] Sex differences at the chromosome and molecular level exist in all human cells, and persist life-long, independent of sex hormones in the ...