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A man is an adult male human. Before adulthood, a male child or adolescent is referred to as a boy. Like most other male mammals, a man's genome usually inherits an X chromosome, X chromosome from the mother and a Y chromosome, Y chromosome from the father. Sex differentiation of the male fetus is governed by the SRY gene on the Y chromosome. During puberty, hormones which stimulate androgen production result in the development of secondary sexual characteristics that result in even more differences between the sexes. These include greater muscle mass, greater height, the growth of facial hair and a lower body fat composition. Male anatomy is distinguished from female anatomy by the male reproductive system, which includes the testicles, sperm ducts, prostate gland and epididymides, and human penis, penis. Secondary sex characteristics include a narrower pelvis and hips, and smaller breasts and Nipple, nipples. Throughout human history, traditional gender roles hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Sexual Characteristic
A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during puberty—and include enlarged breasts and widened hips of females, facial hair and Adam's apples on males, and pubic hair on both. In non-human animals, they can start to appear at sexual maturity—and include, for example, the manes of male lions, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes. Secondary sex characteristics are particularly evident in the sexual dimorphism, sexually dimorphic phenotypic traits that distinguish the sexes of a species. In evolution, secondary sex characteristics are the product of sexual selection for traits that show fitness (biology), fitness, giving an organism an advantage over its rivals in courtship and in aggression, aggressive interactions. Many characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human History
Human history or world history is the record of humankind from prehistory to the present. Early modern human, Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers. They Early expansions of hominins out of Africa, migrated out of Africa during the Last Ice Age and had spread across Earth's continental land except Antarctica by the end of the Ice Age 12,000 years ago. Soon afterward, the Neolithic Revolution in West Asia brought the first systematic Agriculture, husbandry of plants and animals, and saw many humans transition from a nomadic life to a Sedentism, sedentary existence as farmers in Civilization, permanent settlements. The growing complexity of human societies necessitated systems of accounting and writing. These developments paved the way for the Cradle of civilization, emergence of early civilizations in Mesopotamia, Ancient Egypt, Egypt, the Indus Valley, and History of China, China, marking the beginning of the ancient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nipple
The nipple is a raised region of tissue on the surface of the breast from which, in lactating females, breast milk, milk from the mammary gland leaves the body through the lactiferous ducts to Breastfeeding, nurse an infant. The milk can flow through the nipple passively, or it can be ejected by smooth muscles, smooth muscular contraction, muscle contractions that occur along with the ductal system. The nipple is surrounded by the areola, which is often a darker colour than the surrounding skin. Male mammals also have nipples but without the same level of function or prominence. A nipple is often called a ''teat'' when referring to non-humans. "Nipple" or "teat" can also be used to describe the flexible mouthpiece of a baby bottle. In humans, the nipples of both males and females can be sexually stimulated as part of sexual arousal. In many cultures, female nipples are sexualized, or regarded as sex objects and evaluated in terms of their physical characteristics and sex appeal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast
The breasts are two prominences located on the upper ventral region of the torso among humans and other primates. Both sexes develop breasts from the same embryology, embryological tissues. The relative size and development of the breasts is a major secondary sex distinction between females and males. There is also considerable Bra size, variation in size between individuals. Permanent Breast development, breast growth during puberty is caused by estrogens in conjunction with the growth hormone. Female humans are the only mammals that permanently develop breasts at puberty; all other mammals develop their mammary tissue during the latter period of pregnancy. In females, the breast serves as the mammary gland, which produces and secretes milk to feed infants. Subcutaneous fat covers and envelops a network of lactiferous duct, ducts that converge on the nipple, and these tissue (biology), tissues give the breast its distinct size and globular shape. At the ends of the ducts are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hips
In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint on the outer (lateral) side of the pelvis. The hip region is located lateral and anterior to the gluteal region, inferior to the iliac crest, and lateral to the obturator foramen, with muscle tendons and soft tissues overlying the greater trochanter of the femur. In adults, the three pelvic bones ( ilium, ischium and pubis) have fused into one hip bone, which forms the superomedial/deep wall of the hip region. The hip joint, scientifically referred to as the acetabulofemoral joint (''art. coxae''), is the ball-and-socket joint between the pelvic acetabulum and the femoral head. Its primary function is to support the weight of the torso in both static (e.g. standing) and dynamic (e.g. walking or running) postures. The hip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvis
The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis or pelvic skeleton). The pelvic region of the trunk includes the bony pelvis, the pelvic cavity (the space enclosed by the bony pelvis), the pelvic floor, below the pelvic cavity, and the perineum, below the pelvic floor. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and mainly consists of the reproductive organs and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Penis
In Human body, human anatomy, the penis (; : penises or penes; from the Latin ''pēnis'', initially 'tail') is an external sex organ (intromittent organ) through which males urination, urinate and ejaculation, ejaculate, as Penis, on other animals. Together with the testes and surrounding structures, the penis functions as part of the male reproductive system. The main parts of the penis are the Root of penis, root, Body of penis, body, the epithelium of the penis, including the shaft skin, and the foreskin covering the glans penis, glans. The body of the penis is made up of three columns of tissue (biology), tissue: two Corpus cavernosum penis, corpora cavernosa on the dorsal side and corpus spongiosum penis, corpus spongiosum between them on the ventral side. The Urethra#Male, urethra passes through the prostate gland, where it is joined by the ejaculatory ducts, and then through the penis. The urethra goes across the corpus spongiosum and ends at the tip of the glans as the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epididymides
The epididymis (; : epididymides or ) is an elongated tubular genital organ attached to the posterior side of each one of the two male reproductive glands, the testicles. It is a single, narrow, tightly coiled tube in adult humans, in length; uncoiled the tube would be approximately 6 m (20 feet) long. It connects the testicle to the vas deferens in the male reproductive system. The epididymis serves as an interconnection between the multiple efferent ducts at the rear of a testicle (proximally), and the vas deferens (distally). Its primary function is the storage, maturation and transport of sperm cells. Structure The human epididymis is situated posterior and somewhat lateral to the testis. The epididymis is invested completely by the tunica vaginalis (which is continuous with the tunica vaginalis covering the testis). The epididymis can be divided into three main regions: * The head (). The head of the epididymis receives spermatozoa via the efferent ducts of the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostate Gland
The prostate is an male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the bladder, with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular tissue, as well as connective tissue. The prostate produces and contains fluid that forms part of semen, the substance emitted during ejaculation as part of the male human sexual response cycle, sexual response. This prostatic fluid is slightly Alkalinity, alkaline, milky or white in appearance. The alkalinity of semen helps neutralize the acidity of the vagina, vaginal tract, prolonging the lifespan of sperm. The prostatic fluid is expelled in the first part of ej ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm Duct
The vas deferens (: vasa deferentia), ductus deferens (: ductūs deferentes), or sperm duct is part of the male reproductive system of many vertebrates. In mammals, spermatozoa are produced in the seminiferous tubules and flow into the epididymal duct. The end of the epididymis is connected to the vas deferens. The vas deferens ends with an opening into the ejaculatory duct at a point where the duct of the seminal vesicle also joins the ejaculatory duct. The vas deferens is a partially coiled tube which exits the abdominal cavity through the inguinal canal. Etymology ''Vas deferens'' is Latin, meaning "carrying-away vessel" while ''ductus deferens'', also Latin, means "carrying-away duct". Structure The human vas deferens measures 30–35 cm in length, and 2–3 mm in diameter. It is continuous proximally with the tail of the epididymis, and exhibits a tortuous, convoluted initial/proximal section (which measures 2–3 cm in length). Distally, it forms a dilated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testicle
A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is Homology (biology), homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of Androgen, androgens, primarily testosterone. The release of testosterone is regulated by luteinizing hormone (LH) from the anterior pituitary gland. Sperm production is controlled by follicle-stimulating hormone (FSH) from the anterior pituitary gland and by testosterone produced within the gonads. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and compari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
