Secondary Sex Characteristics in Men
- Increased testes in volume. ( see "What is the normal size of male testicles?").
- Growth of the penis. ( see "What is the normal size of the penis?")
- Skin pigmentation of the scrotum.
- Pollution. Spermatogenesis.
- Sexual behavior. Ability to experience sexual arousal.
- High growth. The length of the body depends on many factors( heredity, living conditions, diseases in childhood and adolescence, etc.).In men, the growth as a whole is higher, as with other things being equal, the growth zones are closed later( because of the later terms of puberty).For men in Russia, according to the latest data, the average height is 178 cm( 12 cm more than for women).
- Large body weight. Weight is determined by both proportions, and developed musculature and high mineral density of bone tissue. In a young adult male normostenic growth of 170 cm on average, the normal weight is about 70 kg( against 64 kg in women of the same height).
- High mineral density of the skeleton .In men, the bone mass accounts for about 15% of the total weight( against 10-12% in women).The peak density( at the age of 30 years) in men is more pronounced, and the decrease in bone density and strength is much slower than in women.
- High percentage of muscle tissue .On average, in men at young and middle age, the mass of the musculature is more than 40-45% of the weight( against 30-35% in women).Muscles are well developed initially and respond better to physical activity.
- Low percentage of fatty tissue .In men under 60, the fat mass is normally less than 22-25% of the total weight. On average, men have a mass of fat 2 times less than women with the same weight. To the stronger sex it is easier to lose weight. Weight loss is possible without a significant restriction of calorie content of food.
- Abdominal obesity ( for details).This type of overweight is characterized by the deposition of fat inside the abdominal cavity. Abdominal obesity is often accompanied by a metabolic disorder( dyslipidemia, diabetes, gout).
- Shorter body and relatively long limbs .This is particularly noticeable when measuring growth in the sitting position. In men, this growth is 5 cm less( with the same length of body).In general, the differences appear due to the proportions of the skeleton and the features of the deposition of fat in the sciatic region.
- The men have relatively wide shoulders and a narrow basin with respect to the .The body can be schematically represented as an inverted pyramid.
- Broad chest. The average chest height in young men is 10% larger. In men, the thorax is longer, that is, occupies the greater part of the trunk than the abdomen.
- Narrow pelvis. The pelvis is narrower( an average of 5 cm), deeper, the ileum is not deployed outward, the pelvic cavity is less bulky, and the size of the inlet and outlet is much narrower. The pelvis itself is thicker and more inactive. Such a pelvis provides reliable support to internal organs. A narrow pelvis allows men to achieve greater speed in running.
- The male skull is characterized by a relatively large size, pronounced superciliary arches, occipital mounds, massive lower jaw.
- In men, regarding , a greater pneumatization of the bones of the skull is .Bones with air spaces( sinuses) are massive, and the sinuses themselves are more voluminous. Pneumatization of the skull bones provides additional protection and thermal insulation.
- Larger teeth with characteristic odontoscopic features. Researchers also found the fact of a sexual difference in the size of the alveolar arch and bone skies.
- The form of the larynx with developed protrusion ( prominentia laryngea).The growth of cartilage forms the so-called Adam's apple, that is, the "Adam's apple".
- Lower Voice Voice .Articulation depends on the thickness of the ligaments and the size of the glottis. Mutation of the voice in young men occurs early enough and accompanies the growth of the larynx.
- Growth of terminal hair on the face and body according to the male type .Androgen-dependent hair growth zones include the facial skin( chin, skin over the upper lip, the sideburn area), neck, chest, back, stomach, shoulders( read "Methods of accelerating the growth of the beard").
- Growth of hair in the armpits and pubic by the male type ( a rhombus facing one vertex to the navel).
- Androgenic alopecia .The characteristic alopecia parietal and frontal areas associated with the effect of male sex hormones on hair follicles.
- In men, , lumbar lordosis is not pronounced( less bending of the spine).
- Men's posture - the representatives of the stronger sex stand straight or slightly recline. This feature is formed due to differences in the musculoskeletal system.
- Abdominal( diaphragmatic) type of respiration .In boys and girls of the first year of life, the diaphragmatic type of respiration predominates, then the diaphragmatic-thoracic type is more often observed. From the age of 8-10 years, sex differences appear. The boys have diaphragmatic breathing, the girls have a thoracic breathing.
- Relatively large mass of adrenal glands ( in comparison with females) with a relatively smaller mass of all other endocrine glands. Adrenal glands are organs that help to withstand stress, extreme stress and are responsible for behavioral reactions( aggression, struggle, defense).
- The skin of men is more thick( dermis 15-20%, and the stratum corneum of epidermis - 40-50%), darker color, greater activity of sebaceous and sweat glands.
Secondary sexual characteristics are formed during puberty. Their appearance is associated with an increase in the level of certain blood hormones( in men - testosterone and its metabolites).Secondary sexual characteristics characterize the maturity of the organism and its gender identity.
Occurrence of secondary sex signs
In children before adolescence, sex differences are determined by genetics and gonads. The male chromosome set is normal - 46 XY.This genetics corresponds to a bookmark still in the prenatal period and a further development of the gonads of the testicles and, accordingly, of the external genital organs by the male type.
In childhood( average 8-9 years), there are no other significant physical differences between boys and girls. Then begins the period of puberty, that is, the puberty of boys. In the opening, the secretion of gonadotropin releasing hormone hypothalamus sharply increases. This biologically active substance acts on the pituitary gland. As a result, in this part of the endocrine system, the production of gonadotropins is increasing, which in turn stimulates the gonads.
List of signs of
Morphological differences between men and women are particularly clearly manifested in adults of young and middle age. Some of the secondary signs of sex are obvious, while others may be less noticeable. The list of differences includes the characteristics of the hairline, skin, skeleton structure, etc.
List of male secondary sexual characteristics:
Absence of secondary sexual characteristics in men
Secondary sexual characteristics appear during puberty. The terms of this period in the life of each person are individual.
Such adolescents are examined by a pediatrician, endocrinologist, urologist and andrologist. In addition, medical care may be required for those young men who, 4.5 years after the onset of puberty, have not reached the fifth( final) stage of sexual development, that is, full maturity.
Doctor-endocrinologist Tsvetkova IG
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