And do you know what is the essence of the changes that occur in the mammary glands during pregnancy? The mammary glands are enlarged, but the changes are not only about their size.
The fact is that under the influence of prolactin, placental lactogen, progesterone and estrogens, adipose tissue of the breast is replaced by secretory, capable of producing milk.
Prolactin and other mentioned hormones are responsible for the production of milk, but not for its delivery to the consumer, that is – all these hormones do not provide the excretion of milk from the breast. “Delivery” deals with the hormone oxytocin, which is produced in the hypothalamus. Oxytocin causes a reduction in muscle-type cells located in the breast, and thus “squeezes” milk from the breast. Oxytocin also has a stimulating effect on the muscles of the uterus, increasing its contractile activity and tone. As a result, oxytocin plays an important role during childbirth.
It is believed that oxytocin is involved in the formation of such a bright and valuable sensation as orgasm. During orgasm, women increase the concentration of oxytocin in the blood.
Much attention is paid to the study of the effect of oxytocin on the human psyche. There is still work to be done in this area, but it has been proven that oxytocin acts differently on men and women, in accordance with the gender model of social behavior. Women (“homemakers”) oxytocin makes them more generous and trusting, and men (“defenders”) enhances a critical attitude towards others. But there is something in common in the psychotropic effects of oxytocin – in both sexes, it suppresses anxiety and improves mutual understanding.
By the way, prolactin is also involved in ensuring orgasm in women and for some time after reaching orgasm reduces sexual arousal. Some scientists even propose to assess the degree of sexual satisfaction by the post-orgasmic level of prolactin in the blood, but sexual satisfaction is so multifaceted and complex feeling that it is unlikely that its severity can be judged by the concentration of a single substance.
But back to the pregnancy. Because pregnancy is stressful, it increases the production of all stress hormones, not just prolactin alone. The level of adrenaline, norepinephrine and cortisol in the blood of pregnant women increases. The body by all means tries to protect itself from stress, to make the course of pregnancy as favorable as possible. Any process has two sides – good and bad. Protecting the body, stress hormones simultaneously cause such undesirable phenomena as the appearance of edema, increased blood pressure, increased skin pigmentation, thinning hair on the head and increasing their growth on the body. As they say-you have to pay for everything. But, on the other hand, hormones mutually neutralize the “side effects” of each other. Example-estradiol has a vasodilating effect, compensating for the vasoconstrictive effect of adrenaline.
The phrase “love is a game of hormones” may seem silly to someone, cynical to someone, and ridiculous to someone, but in fact it correctly and accurately reflects the real state of Affairs in the body. Is that the word ” game “can be replaced by” change in blood levels ” to be quite certainly-specifically.
The formation and development of the genitals takes place under the influence of hormones, right?
The formation of sexual desire occurs under the influence of hormones, right? Yes, of course, due to the higher nervous activity, the complexity of behavioral reactions in humans is so high that the emergence of attraction between people can not be reduced to a primitive scheme observed in animals. Dog for interest technoy bitch needs only the scent of certain substances contained in its discharge. Smell includes a mechanism inherent in the level of natural instinct. In man, on the basis of this very natural instinct so much built up that the Foundation is almost invisible. But hormones also control thoughts and emotions. Excess testosterone makes aggressive, excess estradiol or oxytocin, on the contrary, calms. We will discuss this in more detail in a separate Chapter on “Adjuster hormones”, that is, hormones involved in the transfer of information from one nerve cell to another and” tune ” us in a certain way.
Did you know that testosterone stimulates libido  not only in men but also in women?
Ovulation and sperm formation are controlled by hormones.
The culmination of love from a physiological point of view (from a physiological and more!) is sexual intercourse. What ensures this process? Hormones! Testosterone provides an erection, and estradiol increases the secretion of vaginal mucus, facilitating sexual intercourse. Pimp hormones control the whole process from start to finish. And then switch to the result-fertilized egg.
And now-about sad.
Everything passes. In due time, the reproductive function begins to fade and as a result fades completely. Now we’re talking about women’s reproductive functions, the male will be discussed later.
The extinction of any physiological process is caused by a decrease in the production of hormones that provide it.
Menopause, that is, the physiological period of extinction of reproductive function, in women is divided into two main phases: premenopause (or “before menopause”) and postmenopause (or “after menopause”). “Menopause” is the last independent (that is, not caused by taking any drugs) menstruation.
Premenopause begins with a slow, gradual decrease in ovarian function, with a decrease in their production of estrogen. This gradual is expressed in violation of the regular menstrual-ovarian cycle, in the fact that there are delays in menstruation for different periods – from a week to several months. If the ovaries would “turn off” abruptly, immediately, there would be no premenopause. But the abrupt cessation of any physiological function harms the body. In order for everything to go in the most favorable way, the body needs to prepare. So he is preparing for premenopausal.
This period is very unpleasant. The decrease in estrogen content is accompanied in most women by disorders of vasomotor and thermoregulatory functions, which is expressed in the so-called “tides” of blood to the skin of the face, neck and chest, accompanied by a feeling of heat. Irritability increases (remember the soothing effect of estrogens), sleep is disturbed, it feels as if the whole body is affected by some instability… Probably, only after experiencing all this, you can fully realize how important hormones are for the body.
And now, dear readers, try to build your own chain of endocrine changes that lead to menopause. Since the late.
So, the first link…
Estrogens in the ovaries are produced by follicles, so a decrease in their production will result from a decrease in the number of follicles. This process, on the one hand, is the result of numerous ovulation, on the other hand, inhibition of follicular maturation, and the third – common tendency to age-related decrease in the number of follicles (remember how much their baby girls!).
With the first link sorted out, go to the second…
What stimulates the production of hormones? Of course same hormones pituitary gland! So the second link in our chain will be to reduce the production of pituitary hormones responsible for the secretion of estrogen and progesterone in the ovaries – follicle stimulating and luteinizing. Just do not forget about this aspect, as the sensitivity of receptors to hormones! In parallel with the decrease in the production of hormones in the pituitary gland, the sensitivity of ovarian receptors to these hormones will decrease.
The third link, of course, will be a decrease in the production of gonadoliberin in the pituitary gland and epiphysis. Actually, all age-related changes begin with the hypothalamus.
Postmenopause begins with menopause and continues… there is disagreement about the limit to which it continues. Some believe that until the end of life, and others that up to the age of 65-69 years, that is, until the moment when the ovaries ends replacement of functionally active cells inactive cells of connective tissue. But such nuances are not important to us. It is important for us to know what interesting things happen during postmenopause.
The most interesting (from the endocrine point of view) is the “Palace coup”, as a result of which the least active estrogen – estrone takes the crown from estradiol, who ruled autocratically until now, from the moment of birth.
That is, in postmenopausal estrogen begins to prevail among estrogens. The concentration of estrone in the blood exceeds the concentration of estradiol in 3-4 times! Progesterone in postmenopause is not produced at all, the production of estrogen in the ovaries is permanently reduced until it stops completely. All hope only on adipose tissue, which, as already mentioned above, carries out only the final stage of estrogen synthesis-aromatization of androgens.
The main supplier of “semi-finished products” in postmenopause are the adrenal glands, which during this period “give out for processing” more Androstenedione than testosterone. But when aromatization of Androstenedione estrone formed it.
Not only does the body have a pronounced estrogen deficiency, but also among what is available, the majority is the most inactive estrogen. This fact reinforces the deficit of estrogens in postmenopausal women. The result can wait no longer – developing osteoporosis, changes the topography of the deposition of fat reserves, changes in the voice, changes in psycho-emotional sphere, etc. All this, of course, significantly reduces the quality of life of women in menopause.
What to do?
The only way out is to make up for the lack of hormones by taking hormonal drugs. This is a justified and useful intake of hormones, as it aims to compensate for their physiological deficiency. There are so many myths and prejudices surrounding hormone replacement therapy that it will be necessary to devote an entire Chapter to debunking them (and at the same time explaining the essence of the replacement process), which will follow this one.
In the meantime, we leave the women’s Affairs and move on to the men’s.
In men with sex hormones, the situation is much easier. In the sense that in their reproductive age there is no monthly cyclic changes in the concentration of hormones in the blood.
The main androgen, as has been said more than once, is testosterone, which can be processed into estradiol, losing all its “masculinity” or can increase this “masculinity” many times, if it turns into dihydrotestosterone. The main” factories ” for the production of dihydrotestosterone, that is, the areas of the most intense conversion of testosterone into dihydrotestosterone, are the prostate gland and…
You can bet that those who do not know, never and never will be able to correctly guess the second zone, because it is the foreskin of the penis. That’s it.
Dihydrotestosterone is much more active than testosterone and has a wider field of action. Testosterone stimulates the growth, development and functioning of the seminal vesicles, VAS deferens and the epididymis.
Let’s make a small “anatomical” digression from our main topic and remember (or learn) that the organs of the male reproductive system are anatomically divided into internal (testicles, appendages of the testicles, VAS deferens, prostate gland and seminal vesicles) and external (penis and scrotum).
Dihydrotestosterone stimulates the growth, development and functioning of the prostate, testicles, urethra, penis.
The level of androgens in the blood of adult men is subject to severe daily fluctuations. It is maximized in the early morning hours and is minimal around one o’clock in the morning. These fluctuations disappear in old age, when androgen production is significantly reduced.
The level of androgens in the blood determines the sexual activity of men, which, in turn, affects the level of androgens in the blood. The more intense sex life, the more androgens produced in the body. Prolonged sexual abstinence leads to a marked decrease in the concentration of androgens in the blood. Androgen production also increases when thinking about sex, watching erotic films or reading similar literature. The biological purpose of the male is to fertilize as many females as possible. The activity of male sex hormones in the male body is subject to the motto: “we will Do everything possible for the next sexual intercourse” and”we will support in Every possible way the one who works well”.
An interesting detail – male sexual behavior, that is, all the actions of men that Express their gender, is determined by “weak” testosterone, not “powerful” dihydrotestosterone. You know why? To influence the sexual centers of the hypothalamus (Oh, this ubiquitous hypothalamus!) testosterone must be converted to estradiol by the familiar flavor. Here’s an interesting “parsley” is obtained – the male sex hormone for formation and stimulation of male sexual behavior need to turn into the female sex hormone. I want to exclaim: “What fun these hormones! All they have ipodlivnem!”. But the nature of these “Vapaavuori” need some reason, otherwise they would not be.
Dihydrotestosterone aromatized in estradiol can not and therefore in the regulation of sexual behavior does not take part.
And here’s another interesting detail-the introduction of estradiol into the body does not cause stimulation of male sexual behavior. Unlike the administration of testosterone. That is, the sexual centers of the hypothalamus do not need to stimulate estradiol, “prepared” by someone else. They are stimulated only by the estradiol that they prepare themselves.
But dihydrotestosterone is not idle-it provides an erection, sperm production and ejaculation (ejaculation). Thus for full male sexual behavior are needed and testosterone, and dihydrotestosterone. Incidentally, an antagonist of androgen is progesterone, which “oppresses masculinity”, that is, inhibits behavioral responses of male type. And, as mentioned above, progesterone inhibits the process of processing testosterone into dihydrotestosterone. Figuratively speaking, the progesterone gets in masculinity from three sides – reduces libido, inhibits erections inhibits the production of sperm. It begs the question-if from a biological point of view the meaning of the existence of men is to commit as many sexual acts as possible, then why do the testicles and adrenal glands produce progesterone? The answer is simple: any activity should not only be stimulated, but also oppressed. Every car has an engine and a brake. From the biological point of view, a man should think not only about sexual acts, but also about rest, about eating, otherwise you can die from exhaustion.
Spermatogenesis (the scientific name for the formation of sperm in the testicles) is triggered when puberty luteinizing hormone pituitary gland. This hormone acts on the cells of the testicles, which produce testosterone, and testosterone, after conversion to dihydrotestosterone, “starts” spermatogenesis and stimulates it.
An interesting detail – hormone replacement therapy with testosterone deficiency does not stimulate spermatogenesis, although, in theory, it would seem, had to do it, because the body receives the right amount of hormone. But with the introduction of testosterone from the outside, it is impossible to achieve such a concentration in the testicles that could start and maintain spermatogenesis. Excessively increase the dose of administered testosterone to the testes it has accumulated enough, it is impossible. This will cause the body as a whole more harm than testosterone deficiency.
Spermatogenesis should be distinguished from sperm formation. Sperm consists of sperm and so-called seminal fluid, which is a mixture of prostate secretions and seminal vesicles. Formed in the testicles, sperm Mature in the appendages of the testicles, and then begin their way out during ejaculation. Start alone, but in the way they are joined by the aforementioned secrets, and the result is sperm.
Puberty in boys begins at 12-14 years. Its first sign is an increase in the testicles, which first begin to produce hormones, and then – sperm. In parallel with the testicles, the penis begins to increase in size, erections arise, and then – pollutions. Begins hair growth on the male type, change the voice, actively growing bones and muscles. All these changes are caused by an increase in the production of androgens, which is stimulated by increased production of gonadotropins in the pituitary gland (and so on, we will not repeat). Having reached physiological values characteristic of a healthy adult organism, the production of male sex hormones remains at this level until about forty-five years of age, and then begins to decline (on average by 1-1. 2 % annually). In the testes reduces the production of androgens, at the same time decreases the sensitivity of the testicles to testosterone, which affects sperm quality (reduced sperm count in 1 ml), in the testes degenerative changes occur (functionally active cells are replaced by inactive), worsening erection… And so on, all change “the points” we are not going to enumerate because it is not needed and so everything is clear. It is better to focus on the features of age-related extinction of male sexual function.
Note that we are talking about “age-related decline of male sexual function”, not”male climax”. The fact is that the term “male climax” is controversial and is not used by all doctors, despite the fact that it is recognized by such an authoritative medical authority as the world health organization.
In General, the age-related extinction of male sexual function is very different from the same process in women, because it occurs very slowly and almost imperceptibly, without such phenomena as, for example, “tides” or increased emotional instability. The lack of a clear physiological (and age) no borders allows you to select “male menopause” as a specific period in a man’s life. The extinction of the male sexual function can last until old age, its rate is highly dependent on the individual characteristics of the body. A woman in her seventies can no longer conceive, but some men in their seventies can impregnate a woman. Another feature is the increased production of estrogen in the adrenal glands.
But we should not think that the extinction of sexual function in men does not create problems. The main male problem is prostate adenoma – a benign tumor that very often occurs in men over 45 years. Adenoma is a growth of prostate tissue and the emergence of benign tumors in it, the so-called”nodes”. The cause of this disease is a imbalance (imbalance) between androgens and estrogens in the body. Androgens become less and estrogens-more, and these changes trigger pathological growth of prostate cells.
Growing, the adenoma compresses the wall passing through it the urethra (the urethra) and pushes on the bladder, which violates urination until acute urinary retention.
Please answer this question – why are obese men more likely to get prostate adenoma?
If you find it difficult to answer, then remember what hormones are produced by adipose tissue.
Estrogen! In the bodies of obese men, more estrogen is produced, that is, they are more pronounced imbalance between androgens and estrogens, causing the development of adenoma.
An increase in the level of estrogen in the blood leads to the fact that in old age, men develop obesity in the female type, in which fat is deposited in the buttocks, thighs and Breasts.
Summary (this time very short)
The organisms of men and women have many differences, including endocrine. But in the field of sexual hormonal regulation, there are two main differences. First, men in reproductive age do not have monthly cyclic changes in the concentration of hormones in the blood. Secondly, the age-related extinction of sexual function in men is much slower than in women, depends heavily on the individual characteristics of the body and has no clear physiological and age boundaries.