Testosteron

[missouriteen]

What dose testosteron do to the body?

[Whisper]

In both men and women, testosterone plays a key role in health and well-being as well as in sexual functioning. Examples include enhanced libido (http://en.wikipedia.org/wiki/Libido), increased energy, increased production of red blood cells and protection against osteoporosis (http://en.wikipedia.org/wiki/Osteoporosis). On average, an adult human (http://en.wikipedia.org/wiki/Human) male body produces about forty to sixty times more testosterone than an adult female body, but females are more sensitive to the hormone.[1] (http://en.wikipedia.org/wiki/Testosteron#cite_note-0) However the overall ranges for male and female are very wide, such that the ranges actually overlap at the low end and high end respectively.

http://en.wikipedia.org/wiki/Testosteron

Early postnatal effects

Early postnatal effects are the first visible effects of rising androgen levels in childhood, and occur in both boys and girls in puberty.


Adult-type body odour (http://en.wikipedia.org/wiki/Body_odour)
Increased oiliness of skin and hair, acne (http://en.wikipedia.org/wiki/Acne_vulgaris)
Pubarche (http://en.wikipedia.org/wiki/Pubarche) (appearance of pubic hair (http://en.wikipedia.org/wiki/Pubic_hair))
Axillary hair (http://en.wikipedia.org/wiki/Axillary_hair)
Growth spurt (http://en.wikipedia.org/wiki/Growth_spurt), accelerated bone maturation (http://en.wikipedia.org/wiki/Epiphysis)
Develop hair (http://en.wikipedia.org/wiki/Hair) on upper lip and sideburns (http://en.wikipedia.org/wiki/Sideburn).


[edit (http://en.wikipedia.org/w/index.php?title=Testosterone&action=edit&section=10)] Advanced postnatal effects

Advanced postnatal effects begin to occur when androgen has been higher than normal adult female levels for months or years. In males these are usual late pubertal effects, and occur in women after prolonged periods of heightened levels of free testosterone in the blood.


Phallic (http://en.wikipedia.org/wiki/Phallic) enlargement or clitoromegaly (http://en.wikipedia.org/wiki/Clitoromegaly)
Increased libido (http://en.wikipedia.org/wiki/Libido) and frequency of erection (http://en.wikipedia.org/wiki/Erection) or clitoral engorgement
Pubic hair extends to thighs and up toward umbilicus (http://en.wikipedia.org/wiki/Navel)
Facial hair (http://en.wikipedia.org/wiki/Facial_hair) (sideburns (http://en.wikipedia.org/wiki/Sideburns), beard (http://en.wikipedia.org/wiki/Beard), moustache (http://en.wikipedia.org/wiki/Moustache))
Chest hair (http://en.wikipedia.org/wiki/Chest_hair), periareolar (http://en.wikipedia.org/w/index.php?title=Periareolar&action=edit&redlink=1) hair, perianal (http://en.wikipedia.org/w/index.php?title=Perianal&action=edit&redlink=1) hair
Subcutaneous fat in face decreases
Increased muscle strength and mass [7] (http://en.wikipedia.org/wiki/Testosteron#cite_note-6)
Deepening of voice
Growth of the Adam's apple (http://en.wikipedia.org/wiki/Adam%27s_apple)
Growth of spermatogenic (http://en.wikipedia.org/wiki/Spermatogenic) tissue in testes, male fertility (http://en.wikipedia.org/wiki/Fertility)
Growth of jaw, brow, chin, nose, and remodeling of facial bone contours
Shoulders become broader and rib cage expands
Completion of bone maturation and termination of growth. This occurs indirectly via estradiol (http://en.wikipedia.org/wiki/Estradiol) metabolites (http://en.wikipedia.org/wiki/Metabolites) and hence more gradually in men than women.


[edit (http://en.wikipedia.org/w/index.php?title=Testosterone&action=edit&section=11)] Adult testosterone effects

Adult testosterone effects are more clearly demonstrable in males than in females, but are likely important to both sexes. Some of these effects may decline as testosterone levels decline in the later decades of adult life.


Maintenance of muscle mass and strength [8] (http://en.wikipedia.org/wiki/Testosteron#cite_note-7)
Maintenance of bone density and strength
Libido and clitoral engorgement/penile erection frequency.
Mental and physical energy
The most recent and reliable studies have shown that testosterone does not cause Prostate cancer (http://en.wikipedia.org/wiki/Prostate_cancer), but that it can increase the rate of speed of any existing prostate cancer.[citation needed (http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)] Recent studies have also shown its importance in maintaining cardio vascular health.[citation needed (http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)]
Increase eumelanin (http://en.wikipedia.org/wiki/Eumelanin) and reduce pheomelanin (http://en.wikipedia.org/wiki/Pheomelanin)[citation needed (http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)]

Testosterone regulates the population of thromboxane A2 (http://en.wikipedia.org/wiki/Thromboxane_A2) receptors on megakaryocytes (http://en.wikipedia.org/wiki/Megakaryocytes) and platelets (http://en.wikipedia.org/wiki/Platelets) and hence platelet aggregation in humans ( Ajayi and Halushka 2005, Ajayi et al 1995 ).


BRAIN


As testosterone affects the entire body (often by enlarging; men have bigger hearts, lungs, liver, etc.), the brain is also affected by this "sexual" advancement; the enzyme (http://en.wikipedia.org/wiki/Enzyme) aromatase (http://en.wikipedia.org/wiki/Aromatase) converts testosterone into estradiol (http://en.wikipedia.org/wiki/Estradiol) that is responsible for masculinization (http://en.wikipedia.org/wiki/Masculinization) of the brain in a male fetus.


There are some differences in a male and female brain (the result of different testosterone levels); a clear difference is the size, the male human brain is on average larger, however in females (who generally do not have as high testosterone levels) the corpus callosum (http://en.wikipedia.org/wiki/Corpus_callosum) is proportionally larger. This means that the effect of testosterone is a greater overall brain volume, but a decreased connection between the hemispheres (http://en.wikipedia.org/wiki/Cerebral_hemisphere).[9] (http://en.wikipedia.org/wiki/Testosteron#cite_note-Mark_Solms_.26_Oliver_Turnbull-8)
A study conducted in 1996 found no effects on mood or behavior from the administration of supraphysiologic doses of Testosterone for 10 weeks to healthy men.[10] (http://en.wikipedia.org/wiki/Testosteron#cite_note-9)

(http://en.wikipedia.org/wiki/Testosteron#cite_note-9)
The literature suggests that attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans, though the literature is rather sparse. Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimer’s type,[11] (http://en.wikipedia.org/wiki/Testosteron#cite_note-10) a key argument in Life Extension Medicine for the use of testosterone in anti-aging therapies. Much of the literature, however, suggests a curvilinear or even quadratic relationship between spatial performance and circulating testosterone,[12] (http://en.wikipedia.org/wiki/Testosteron#cite_note-11) where both hypo- and hypersecretion of circulating androgens have negative effects on cognition and cognitively-modulated aggressivity, as detailed above.


Contrary to what has been postulated in outdated studies and by certain sections of the media, aggressive behaviour is not typically seen in hypogonadal men who have their testosterone replaced adequately to the eugonadal/normal range. In fact aggressive behaviour has associated with hypogonadism and low testosterone levels and it would seem as though supraphysiological and low levels of testosterone and hypogonadism (http://en.wikipedia.org/wiki/Hypogonadism) cause mood disorders (http://en.wikipedia.org/wiki/Mood_disorder) and aggressive (http://en.wikipedia.org/wiki/Aggressive) behaviour, with eugondal/normal testosterone levels being important for mental well-being. Testosterone depletion is a normal consequence of aging in men. One consequence of this is an increased risk for the development of Alzheimer’s Disease (http://en.wikipedia.org/wiki/Alzheimer%E2%80%99s_Disease) (Pike et al, 2006, Rosario 2004).