Although at puberty he has signs of virilization, he has developed pronounced gynecomastia. Views Read Edit View history. Besides these changes in height, body composition, and motor skills, the sexual reproductive system triggers many changes during the transition from childhood to adulthood.
It is therefore proposed that gynecomastia probably results from failure of adequate testosterone action on the breast primordia during embryonic differentiation. The ovaries produce an ovumor egg usually with the onset of puberty.
Usual anatomy of internal genitalia. All rights reserved. The egg travels through the oviduct by peristalsis and moving cilia lining the tube toward the uterus.
Download as PDF Printable version. The uterus narrows at the distal end to the cervixthe opening from the uterus to the vagina. Secondary sexual characteristics Sex. Categories : Sexual anatomy. Target cells are specific to the hormone; a hormone specific to a target cell can only affect that target tissue because of the presence of receptors for the hormone on the target cells.
Help Community portal Recent changes Upload file. The level of hormones in the blood must reach a certain threshold amount for the response to occur.
The increased secretion of testosterone from the testes during puberty causes the male secondary sexual characteristics to be manifested. Humans born with sex characteristics that are in any way from both columns are called intersex. Adolescent guys will notice their "Adam's apples," grows larger during this period.
In mammals, sex is determined through hormonal events in utero that under normal circumstances are controlled by the combination of X and Y chromosomes. In castrated male rats this treatment produces little glandular proliferation. Secondary sex characteristics include, for example, the manes of male lions ,  the bright facial and rump coloration of male mandrills , and horns in many goats and antelopes.