Misplaced Pages

#449550

56-544: A boy is a young male human . The term is commonly used for a child or an adolescent . When a male human reaches adulthood, he is usually described as a man . According to the Merriam-Webster Dictionary , a boy is "a male child from birth to adulthood". The word "boy" comes from Middle English boi, boye ("boy, servant"), related to other Germanic words for boy , namely East Frisian boi ("boy, young man") and West Frisian boai ("boy"). Although

112-423: A catheter can be inserted through the urethra to drain urine from the bladder, called an indwelling urinary catheter ; or, to bypass the urethra, a catheter may be directly inserted through the abdominal wall into the bladder, called a suprapubic catheter . This may be to relieve or bypass an obstruction, to monitor how much urine someone produces , or because a person has difficulty urinating, for example due to

168-425: A neurological cause such as multiple sclerosis . Complications that are associated with catheter insertion can include catheter-associated infections , injury to the urethra or nearby structures, or pain. In all mammals , with the exception of monotremes , and in both sexes, the urethra serves primarily to drain and excrete urine, which in mammals, collects in the urinary bladder and is released from there into

224-495: A sexual system called androdioecy . They can also coexist with females and hermaphrodites, a sexual system called trioecy . The sex of a particular organism may be determined by a number of factors. These may be genetic or environmental, or may naturally change during the course of an organism's life. Although most species have only two sexes (either male or female), hermaphroditic animals, such as worms , have both male and female reproductive organs. Not all species share

280-466: A benchmark for boys to assess their peers. The adherence to these group norms often holds more weight than the mere affiliation to the group. In fact, boys who do not conform to these norms are often evaluated lower than those who, despite being strangers, conform to the group’s norms. This phenomenon underscores the powerful influence of group norms in shaping attitudes and actions, and the social implications of conformity. Boys who defy gender norms may face

336-423: A black man as "boy". During an event promoting the 2017 boxing bout between Floyd Mayweather Jr. and Conor McGregor , the latter told the former to "dance for me, boy." The remarks led several boxers – including Mayweather and Andre Ward – as well as multiple commentators to accuse McGregor of racism. Human sex is determined at fertilization when the genetic sex of the zygote is determined by whether

392-452: A common sex-determination system . In most animals , including humans , sex is determined genetically ; however, species such as Cymothoa exigua change sex depending on the number of females present in the vicinity. Most mammals , including humans , are genetically determined as such by the XY sex-determination system where males have XY (as opposed to XX in females) sex chromosomes . It

448-454: A few species. Anisogamy appears to have evolved multiple times from isogamy; for example, female Volvocales (a type of green algae) evolved from the plus mating type. Although sexual evolution emerged at least 1.2 billion years ago, the lack of anisogamous fossil records make it hard to pinpoint when males evolved. One theory suggests male evolved from the dominant mating type (called mating type minus). A common symbol used to represent

504-484: A higher risk of abuse, and may experience more depression than gender-conforming peers, as well as social stigma from parents and peers. The gender policing towards them can increase the risk of alcohol use, anxiety, and depression in adulthood. In some cultures, the birth of a male child (boy) is considered prosperous. Boys perform the majority of child labor around the world compared to girls; 88 million child laborers are boys and 64 million are girls. Boys are also

560-421: A result of insertion of foreign bodies into the urethra such as an electrical wire. Hypospadias and epispadias are forms of abnormal development of the urethra in the male, where the meatus is not located at the distal end of the penis (it occurs lower than normal with hypospadias, and higher with epispadias). In a severe chordee , the urethra can develop between the penis and the scrotum. A tube called

616-404: A sample of urine for an inspection for malignant cells under a microscope, called cytology , as well as examination with a flexible camera through the urethra, called urethroscopy . If a malignancy is found, a biopsy will be taken, and a CT scan will be performed of other body parts (a CT scan of the chest, abdomen and pelvis ) to look for additional metastatic lesions. After the cancer

SECTION 10

#1732838248450

672-418: A way of displaying traits that signify their fitness . Sexual selection is believed to be the driving force behind the development of these characteristics. Differences in physical size and the ability to fulfill the requirements of sexual selection have contributed significantly to the outcome of secondary sex characteristics in each species. In many species, males differ from females in more ways than just

728-456: Is blood in the urine ; a physical medical examination may be otherwise normal, except in late disease. Cancer of the urethra is most often due to cancer of the cells lining the urethra, called transitional cell carcinoma , although it can more rarely occur as a squamous cell carcinoma if the type of cells lining the urethra have changed, such as due to a chronic schistosomiasis infection. Investigations performed usually include collecting

784-399: Is staged , treatment may involve chemotherapy . Passage of kidney stones through the urethra can be painful. Damage to the urethra, such as by kidney stones, chronic infection, cancer, or from catheterisation, can lead to narrowing, called a urethral stricture . The location and structure of the narrowing can be investigated with a medical imaging scan in which dye is injected through

840-399: Is a cylindrical organ filled with spongy tissue. It is the organ used by boys to expel urine . The foreskin of some boys' penises is removed in a process known as circumcision . The scrotum is a loose sac of skin behind the penis which contains the testicles. Testicles are oval-shaped gonads. A boy generally possesses two testicles. Internal male reproductive organs include the vas deferens ,

896-456: Is also possible in a variety of species, including humans, to be XX male or have other karyotypes . During reproduction , a male can give either an X sperm or a Y sperm, while a female can only give an X egg. A Y sperm and an X egg produce a male, while an X sperm and an X egg produce a female . The part of the Y-chromosome which is responsible for maleness is the sex-determining region of

952-407: Is called ejaculation. During puberty, a boy's erect penis becomes capable of ejaculating semen and impregnating a female . A boy's first ejaculation is an important milestone in his development. On average, a boy's first ejaculation occurs at age 13. Ejaculation sometimes occurs during sleep; this phenomenon is known as a nocturnal emission . When a boy reaches puberty, testosterone triggers

1008-405: Is inadequate data for the typical length of the male urethra; however, a study of 109 men showed an average length of 22.3 cm (SD = 2.4 cm), ranging from 15 cm to 29 cm. The urethra in male placental mammals is typically longer than in females. In the human female, the urethra is about 4 cm long, having 6 mm diameter, and exits the body between the clitoris and

1064-421: Is one of the main reasons why boys are preferred over girls by the rural communities in poor countries. In India , by contrast, the majority of adopted children are girls even though boys are preferred in general compared to girls. Male Male ( symbol : ♂ ) is the sex of an organism that produces the gamete (sex cell) known as sperm , which fuses with the larger female gamete, or ovum , in

1120-516: Is one way by which we judge many of our present boys to be quite different from some of those who were here long ago: those that are married have their wives here with them, and build their own houses, and all are busy making their gardens. I have told all the boys that if they wished to stay here and learn, those that had wives must bring them. Multiple politicians – including New Jersey Governor Chris Christie and former Kentucky Congressman Geoff Davis – have been criticized publicly for referring to

1176-470: Is the conduit for semen during orgasm . Urine is removed before ejaculation by pre-ejaculate fluid – called Cowper's fluid – from the bulbourethral gland. Infection of the urethra is urethritis , which often causes purulent urethral discharge. It is most often due to a sexually transmitted infection such as gonorrhoea or chlamydia , and less commonly due to other bacteria such as ureaplasma or mycoplasma ; trichomonas vaginalis ; or

SECTION 20

#1732838248450

1232-484: Is true for many species of birds where the male displays more vibrant colors than the female, making them more noticeable to potential mates. These characteristics have evolved over time as a result of sexual selection, as males who exhibited these traits were more successful in attracting mates and passing on their genes. Urethra The external urethral sphincter is a striated muscle that allows voluntary control over urination. The internal sphincter , formed by

1288-529: The ejaculatory ducts , the urethra , the seminal vesicles , and the prostate gland. Puberty is the process by which children's bodies mature into adult bodies that are capable of reproduction. On average, boys begin puberty at ages 11–12 and complete puberty at ages 16–17. In boys, puberty begins with the enlargement of the testicles and scrotum. The penis also increases in size, and a boy develops pubic hair. A boy's testicles also begin making sperm. The release of semen, which contains sperm and other fluids,

1344-502: The penis in males. In the human male, the urethra is on average 18 to 20 centimeters (7 to 8 inches) long and opens at the end of the external urethral meatus. The urethra is divided into four parts in men, named after the location: These openings are collectively called the verumontanum (colliculus seminalis). The prostatic urethra is a common site of obstruction to outflow of urine in BPH patients Stratified squamous – distally There

1400-401: The sperm cell contains an X or Y chromosome. If the sperm cell contains an X chromosome , the fetus will be XX and, typically, a girl will develop. A sperm cell carrying a Y chromosome results in an XY combination, and typically a boy will develop. Variations from this general rule result in intersex fetuses. In male embryos at six to seven weeks' gestation, "the expression of a gene on

1456-420: The vaginal opening , extending from the internal to the external urethral orifice . The meatus is located below the clitoris. It is placed behind the symphysis pubis , embedded in the anterior wall of the vagina, and its direction is obliquely downward and forward; it is slightly curved with the concavity directed forward. The proximal two-thirds of the urethra is lined by transitional epithelial cells , while

1512-404: The Y chromosome induces changes that result in the development of the testes". At approximately nine weeks' gestation, the production of testosterone by a male embryo results in the development of the male reproductive system. The male reproductive system includes both external and internal organs. The external organs include the penis , the scrotum , and the testicles (or testes). The penis

1568-650: The Y-chromosome, the SRY . The SRY activates Sox9 , which forms feedforward loops with FGF9 and PGD 2 in the gonads , allowing the levels of these genes to stay high enough in order to cause male development; for example, Fgf9 is responsible for development of the spermatic cords and the multiplication of Sertoli cells , both of which are crucial to male sexual development. The ZW sex-determination system , where males have ZZ (as opposed to ZW in females) sex chromosomes, may be found in birds and some insects (mostly butterflies and moths ) and other organisms. Members of

1624-423: The beginnings of the anal canal , with a wall forming between these two inpouchings called the urorectal septum . The urogenital sinus divides into three parts, with the middle part forming the urethra; the upper part is largest and becomes the urinary bladder , and the lower part then changes depending on the biological sex of the embryo. The cells lining the urethra (the epithelium) come from endoderm , whereas

1680-497: The bladder. During urination, the smooth muscle lining the urethra relaxes in concert with bladder contraction(s) to forcefully expel the urine in a pressurized stream. Following this, the urethra re-establishes muscle tone by contracting the smooth muscle layer, and the bladder returns to a relaxed, quiescent state. Urethral smooth muscle cells are mechanically coupled to each other to coordinate mechanical force and electrical signaling in an organized, unitary fashion. The male urethra

1736-440: The connective tissue and smooth muscle parts are derived from mesoderm . After the third month, urethra also contributes to the development of associated structures depending on the biological sex of the embryo. In the male, the epithelium multiples to form the prostate . In the female, the upper part of the urethra forms the urethra and paraurethral glands . The urethra is the vessel through which urine passes after leaving

Boy - Misplaced Pages Continue

1792-399: The contents of the urethra. Further along the urethra there are pseudostratified columnar and stratified columnar epithelia. The lining becomes multiple layers of flat cells near the end of the urethra, which is the same as the external skin around it. There are small mucus -secreting urethral glands, as well as bulbo-urethral glands of Cowper, that secrete mucous acting to lubricate

1848-621: The context of gender , such as for gender role or gender identity of a man or boy . For example, according to Merriam-Webster, "male" can refer to "having a gender identity that is the opposite of female". According to the Cambridge Dictionary, "male" can mean "belonging or relating to men". Male can also refer to a shape of connectors . Species that are divided into females and males are classified as gonochoric in animals, as dioecious in seed plants and as dioicous in cryptogams . Males can coexist with hermaphrodites,

1904-486: The development of secondary sex characteristics. A boy's muscles increase in size and mass, his voice deepens, his bones lengthen, and the shape of his face and body changes. The increased secretion of testosterone from the testicles during puberty causes the male secondary sexual characteristics to be manifested. Male secondary sex characteristics include: Boys across various age groups are often part of social circles that establish their own unique norms. These norms serve as

1960-514: The distal third is lined by stratified squamous epithelial cells . Between the superior and inferior fascia of the urogenital diaphragm , the female urethra is surrounded by the urethral sphincter . The urethra in female placental mammals is typically shorter than in the male. The cells lining the urethra (the epithelium ) start off as transitional cells as it exits the bladder, which are variable layers of flat to cuboidal cells that change shape depending on whether they are compressed by

2016-425: The dominant individual in a group becomes female while the other ones are male. In many arthropods , sex is determined by infection with parasitic , endosymbiotic bacteria of the genus Wolbachia . The bacterium can only be transmitted via infected ova, and the presence of the obligate endoparasite may be required for female sexual viability. Male animals have evolved to use secondary sex characteristics as

2072-709: The exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian * bō-ja ("little brother"), a diminutive of the Germanic root * bō- ("brother, male relation"), from Proto-Indo-European * bhā- , * bhāt- ("father, brother"). The root is also found in Norwegian dialectal boa ("brother"), and, through a reduplicated variant * bō-bō- , in Old Norse bófi , Dutch boef "(criminal) knave, rogue", German Bube ("knave, rogue, boy"). Furthermore,

2128-400: The female and male gamete-producing organisms and structures but also the structures of the sporophytes that give rise to male and female plants. The evolution of anisogamy led to the evolution of male and female function. Before the evolution of anisogamy, mating types in a species were isogamous : the same size and both could move, catalogued only as "+" or "-" types. In anisogamy,

2184-475: The historical evidence favours "the conclusion of the French classical scholar Claude de Saumaise (Salmasius, 1588–1683)" that it is derived from θρ , the contraction of a Greek name for the planet Mars, which is Thouros . Borrowed from Old French masle , from Latin masculus ("masculine, male, worthy of a man"), diminutive of mās ("male person or animal, male"). In humans, the word male can be used in

2240-422: The infection is treated, so that they do not spread the infection to others. Because of this spread, which may occur during an incubation period before a person gets symptoms, there is often contact tracing so that sexual partners of an affected person can be found and treatment offered. Cancer can also develop in the lining of the urethra. When cancer is present, the most common symptom in an affected person

2296-529: The insect order Hymenoptera , such as ants and bees , are often determined by haplodiploidy , where most males are haploid and females and some sterile males are diploid . However, fertile diploid males may still appear in some species, such as Cataglyphis cursor . In some species of reptiles, such as alligators , sex is determined by the temperature at which the egg is incubated. Other species, such as some snails , practice sex change: adults start out male, then become female. In tropical clown fish ,

Boy - Misplaced Pages Continue

2352-406: The involuntary smooth muscles lining the bladder neck and urethra, receives its nerve supply by the sympathetic division of the autonomic nervous system . The internal sphincter is present both in males and females. The urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus . Its length differs between the sexes, because it passes through

2408-514: The male sex is the Mars symbol ♂, a circle with an arrow pointing northeast . The Unicode code-point is: The symbol is identical to the planetary symbol of Mars . It was first used to denote sex by Carl Linnaeus in 1751. The symbol is sometimes seen as a stylized representation of the shield and spear of the Roman god Mars . According to William T. Stearn , however, this derivation is "fanciful" and all

2464-494: The mating type is called a gamete. The male gamete is smaller than the female gamete, and usually mobile. Anisogamy remains poorly understood, as there is no fossil record of its emergence. Numerous theories exist as to why anisogamy emerged. Many share a common thread, in that larger female gametes are more likely to survive, and that smaller male gametes are more likely to find other gametes because they can travel faster. Current models often fail to account for why isogamy remains in

2520-421: The molecular level) to anisogamous species with gametes of male and female types to oogamous species in which the female gamete is very much larger than the male and has no ability to move. There is a good argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for sexual reproduction . Accordingly, sex is defined across species by

2576-457: The primary victims of hazardous child labor. They are mainly employed in the agriculture , construction and mining sectors. Boy workers also account for about 87 percent of those who died on the job between 2003 and 2016 in the US. Boys are given a basic reading, writing and mathematics skill and then forced to pursue their father's profession in order to alleviate financial burden of the family. This

2632-437: The process of fertilisation . A male organism cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually . Most male mammals , including male humans, have a Y chromosome , which codes for the production of larger amounts of testosterone to develop male reproductive organs . In humans, the word male can also be used to refer to gender , in

2688-572: The production of sperm. For example, in some insects and fish, the male is smaller than the female. In seed plants, the sporophyte sex organ of a single organism includes both the male and female parts. In mammals, including humans, males are typically larger than females. This is often attributed to the need for male mammals to be physically stronger and more competitive in order to win mating opportunities. In humans specifically, males have more body hair and muscle mass than females. Birds often exhibit colorful plumage that attracts females. This

2744-446: The social sense of gender role or gender identity . The use of "male" in regard to sex and gender has been subject to discussion . The existence of separate sexes has evolved independently at different times and in different lineages , an example of convergent evolution . The repeated pattern is sexual reproduction in isogamous species with two or more mating types with gametes of identical form and behavior (but different at

2800-450: The time it was called "ureter". Thereafter, terms "ureter" and "urethra" were variably used to refer to each other thereafter for more than a millennia. It was only in the 1550s that anatomists such as Bartolomeo Eustacchio and Jacques Dubois began to use the terms to specifically and consistently refer to what is in modern English called the ureter and the urethra. Following this, in the 19th and 20th centuries, multiple terms relating to

2856-422: The type of gametes produced (i.e.: spermatozoa vs. ova) and differences between males and females in one lineage are not always predictive of differences in another. Male/female dimorphism between organisms or reproductive organs of different sexes is not limited to animals; male gametes are produced by chytrids , diatoms and land plants , among others. In land plants, female and male designate not only

SECTION 50

#1732838248450

2912-402: The urethra. The urethra consists of three coats: muscular, erectile, and mucous, the muscular layer being a continuation of that of the bladder. Somatic (conscious) innervation of the external urethral sphincter is supplied by the pudendal nerve . In the developing embryo , at the hind end lies a cloaca . This, over the fourth to the seventh week, divides into a urogenital sinus and

2968-497: The urethra. In addition, the closing mechanisms of the urethra, together with immunoglobulins , largely prevent germs from penetrating the inside of the body. In marsupials , the female's urethra empties into the urogenital sinus . The word "urethra" comes from the Ancient Greek οὐρήθρα – ourḗthrā . The stem "uro" relating to urination, with the structure described as early as the time of Hippocrates . Confusingly however, at

3024-401: The urinary meatus into the urethra, called a retrograde urethrogram . Additional forms of imaging, such as ultrasound , computed tomography and magnetic resonance imaging may also be used to provide further details. Injuries to the urethra (e.g., from a pelvic fracture ) Foreign bodies in the urethra are uncommon, but there have been medical case reports of self-inflicted injuries,

3080-474: The viruses herpes simplex virus and adenovirus . Investigations such as a gram stain of the discharge might reveal the cause; nucleic acid testing based on the first urine sample passed in a day , or a swab of the urethra sent for bacterial culture and sensitivity may also be used. Treatment usually involves antibiotics that treat both gonorrhoea and chlamydia, as these often occur together. A person being treated for urethritis should not have sex until

3136-474: The word may be related to Bōia , an Anglo-Saxon personal name. Historically, in the United States and South Africa, "boy" was used not only for domestic servants but also more generally as a disparaging term for black men; the term implied a subservient status. Thomas Branch, an early African-American Seventh-day Adventist missionary to Nyassaland ( Malawi ) referred to the native students as "boys": There

#449550