The different species that populate nature reproduce in different ways. One of them is sexual reproduction .
This type of reproduction requires the existence of differentiated structures that allow such reproduction to take place. In a large number of species (including ours) there are two differentiated biological sexes. And in many of these both sexes present differences at a biological morphological level beyond the gonad. This is sexual dimorphism: each of the sexes of the same species has certain characteristics on a biological level.
The human being is one of the species in which this dimorphism is observed. Below are some of the main biological differences between men and women .
Main biological differences between men and women
Originally, all human organisms begin to develop with female characteristics and then either begin to masculinize biologically due to the effect of certain hormones such as testosterone or continue such feminized development. In some cases such masculinisation does not occur at all , or occurs in part despite having a female sexual karyotype.
Regardless of the case, once the chromosomal and biological sex has been assigned , the physical characteristics that will develop in the foetus will be slightly different (initially with little perceptible differences) and will cause biological differences to appear in the long run, which will be increasingly visible (especially from adolescence onwards due to hormonal changes). The following are some of the main biological differences between men and women
One of the biological differences between both sexes, which in fact causes the distinction between female and male, is found in the sex chromosomes. While the female has two X chromosomes (being XX), in the male there is one X and one Y chromosome (XY) which will generate among other things a differentiated synthesis of proteins and hormones.
This difference also means that men are generally more likely to suffer from genetic disorders linked to the sex chromosomes, as women have two copies of the same chromosome which may mean that the same problem is not expressed.
2. Hormonal differences
Another of the most well-known biological differences between men and women is the presence of different hormonal rhythms and the presence of different proportions of hormones according to sex. For example, men have much higher levels of testosterone than women for most of their lives, while women synthesize more estrogen .
This influences and causes the presence of specific physical and physiological functioning characteristics in both sexes, visible especially at and after puberty. Behaviour is also affected, although it is largely mediated by education.
The different hormonal rhythms also mean that puberty usually starts earlier in women than in men.
3. Neurological and cerebral differences
The brain is one of the organs in which differences between the two sexes can be observed. In general, the male brain can be up to 11 percent larger and have a higher proportion of white matter, while the female brain is usually denser and has a higher proportion of grey matter .
There are more developed areas of the brain according to sex: in women the corpus callosum and splenius are usually larger, while areas such as the preoptic area of the hypothalamus, the amygdala and the parietal cortex are larger in men. The supraquiasmatic nucleus also has differences in shape in the two sexes.
Some of the brain and nerve circuits we use differ or are connected differently according to sex, for example in terms of sexual stimulation or pain processing . Also the level of stimulation needed to cause a physiological reaction in response to an emotional stimulus may differ, with less stimulation needed in women (although at the level of feeling there may be no difference).
The organs in which the greatest sexual dimorphism from the moment of birth are the genitals , with each sex presenting a type of gonads and reproductive system.
The action of the hormones causes a greater amount of body hair to appear in men than in women, both on the face and the rest of the body.
6. Weight, height, and bone and muscle mass
One of the most well-known differences between men and women is the different muscle and bone development. In general, in our species the male tends to have a greater development in both aspects and to have greater weight, height and strength.
7. Fat distribution
The metabolism also shows some differences at the biological level. The action of hormones such as estrogens causes that, after eating, women tend to store a greater amount of body fat and hinders the consumption of these. This is why it is more complicated for a woman to lose weight or develop muscle mass than for a man.
8. Skin and sweat glands
Women’s skin tends to be thinner and dryer, while men’s skin is usually thicker. Males have more sweat glands, so they sweat more than females.
9. Management of blood flow and body temperature
Generally, blood flow and the ability to maintain body temperature also differ between men and women. While the blood flow of the male along his body is relatively proportional between the different areas, in the female there tends to be a greater flow of blood to the torso and abdomen. This is why they may have greater resistance to hypothermia, although they usually have more difficulty in maintaining heat in the distant areas of the body.
10. Mouth and larynx
On average, women tend to have smaller teeth than men. Likewise, the action of androgens and testosterone during puberty generally causes men’s voices to be low-pitched and women’s voices to be somewhat higher-pitched. Although it exists in both sexes, it is also typical of males that the Adam’s apple is visible (although not in all cases).
11. Heart and lungs
On average, these organs tend to be larger in males. This also plays a role in their greater muscular strength and endurance.
12. Sensory perception
There are also biological differences that can be caused. Generally, men tend to have greater visual acuity, while women have greater auditory and olfactory acuity.
As far as vision is concerned, women tend to have better colour perception (there are women who have up to four types of cones) and have greater angular vision and perception in the dark regardless of whether they have less acuity, while men, in addition to the latter, tend to capture depth and distance better. And despite having less auditory acuity, the male has more facility in locating the sound source.