Keywords of this word: Sex


BISEXUAL

Medical Dictionary

Having the qualities of both sexes. The term is used to describe people who are sexually attracted to both men and women.... Medical Dictionary

HETEROSEXUAL

Medical Dictionary

Sexual attraction to individuals of the opposite sex. (See also HOMOSEXUALITY.)... Medical Dictionary

HOMOSEXUALITY

Medical Dictionary

Sexual activity with a member of the same sex. There has been considerable debate among psychiatrists as to whether homosexuality should be regarded as a normal sexual variant or as a psycho-pathological development or deviation. Although homosexuality is found in virtually every society and culture, there is no society in which it is the predominant or preferred mode of sexual activity. Various attempts have been made to link homosexuality to hormonal factors, particularly lowered TESTOSTERONE levels, or to ?nd a genetic explanation, but there is no evidence for either. Psychoanalytic theories link homosexuality to early child-rearing in?uences, in particular the close-binding and intimate mother.

The number of homosexual men and women in the UK is unknown. Re-analysis of the Kinsey report suggests that only 3 per cent of adult men have exclusively homosexual leanings and a further 3 per cent have extensive homosexual and heterosexual experience. Homosexuality among women (lesbianism) seems to be less common. Some homosexual men have high rates of sexual activity and multiple partners and, as with heterosexual men and women, this increases the risk of acquiring sexually transmitted diseases, unless appropriate precautionary measures are taken – for example, the use of condoms for penetrative sex, whether vaginal or anal. It was in homosexual males that the virus responsible for AIDS (see AIDS/HIV) was ?rst identi?ed, but the infection now occurs in both sexes.... Medical Dictionary

INTERSEXUALITY

Medical Dictionary

Intersexuality is a state of indeterminate sexuality of an individual, and may present in many di?erent forms. A characteristic is that only one type of gonad – testis or ovary – is present; in a HERMAPHRODITE both types are present. Intersexuality may be due to a fault in the genetic mechanism of sex determination as early as conception, or to later errors in sexual di?erentiation of the embryo and fetus, or after birth. Some cases may result from abnormal metabolism of the sex hormones, or may be drug-induced (for example, women given androgens [see ANDROGEN] or PROGESTERONE for repeated miscarriages may give birth to girls with some genital VIRILISATION). Abnormalities of the sex chromosomes may be associated with delayed (or failure of) sexual development, so that the individual shows some of the characteristics (often underdeveloped) of both sexes. Some of the more common presentations of the condition include HYPOGONADISM, CRYPTORCHIDISM, and primary AMENORRHOEA.

Intersexuality inevitably leads to considerable psychological disturbance as the child grows up. It is therefore important to reach an early decision as to the child’s sex – or at least, the sex that he or she is to be brought up as. Surgical or hormonal means should then be employed, when appropriate, to develop the attributes of that sex and diminish those of the other, together with psychological counselling.... Medical Dictionary

NATURAL HERBS THAT INCREASE SEX DRIVE

Natural Herbs That Increase Sex Drive

Natural Herbs That Increase Sex Drive

[catlist id=14 numberposts=100 pagination=yes instance=2 orderby=title order=asc]

... Natural Herbs That Increase Sex Drive

PSYCHOSEXUAL

Medical Dictionary

Relating to the relationships between the behavioural, emotional, mental and physiological characteristics of sex or sexual development.... Medical Dictionary

SECONDARY SEXUAL CHARACTERISTICS

Medical Dictionary

The physical characteristics that develop during PUBERTY as the body matures sexually. Girls’ breasts and genitals increase in size, and, like boys, they grow pubic hair. Boys also grow facial hair, their voice breaks and their genitals grow to adult size.... Medical Dictionary

SEX CHANGE

Medical Dictionary

A major surgical operation, usually coupled with the appropriate hormone treatment (see HORMONES), to change a person’s anatomical sex. The operation is done on transsexual individuals or in those whose sexual organs are neither totally female nor male. Male-to-female sex change is the more common. Such operations should not be performed without rigorous physical and mental assessment of the individual, and should be accompanied by extensive counselling. Some subjects make a satisfactory adjustment to the change of anatomical sex, while others may su?er serious psychological problems. Hormone therapy may need to be continued for life.... Medical Dictionary

SEX CHROMOSOMES

Medical Dictionary

In humans there are 23 pairs of CHROMOSOMES. Male and female di?er in respect of one pair. In the nucleus of female cells, the two members of the pair are identical and are called X chromosomes. In the male nucleus there is one X chromosome paired with a dissimilar, di?erently sized chromosome called the Y chromosome. In the sex cells, after MEIOSIS, all cells in the female contain a single X chromosome. In the male, half will contain an X chromosome and half a Y chromosome. If a sperm with an X chromosome fertilises an ovum (which, as stated, must have an X chromosome) the o?spring will be female; if a sperm with a Y chromosome fertilises the ovum the o?spring will be male. It is the sex chromosomes which determine the sex of an individual.

Sometimes during cell division chromosomes may be lost or duplicated, or abnormalities in the structure of individual chromosomes may occur. The surprising fact is the infrequency of such errors. About one in 200 live-born babies has an abnormality of development caused by a chromosome, and two-thirds of these involve the sex chromosomes. There is little doubt that the frequency of these abnormalities in the early embryo is much higher, but because of the serious nature of the defect, early spontaneous ABORTION occurs.

Chromosome studies on such early abortions show that half have chromosome abnormalities, with errors of autosomes being three times as common as sex chromosome anomalies. Two of the most common abnormalities in such fetuses are triploidy with 69 chromosomes and trisomy of chromosome 16. These two anomalies almost always cause spontaneous abortion. Abnormalities of chromosome structure may arise because of:

Deletion Where a segment of a chromosome is lost.

Inversion Where a segment of a chromosome becomes detached and re-attached the other way around. GENES will then appear in the wrong order and thus will not correspond with their opposite numbers on homologous chromosomes.

Duplication Where a segment of a chromosome is included twice over. One chromosome will have too little nuclear material and one too much. The individual inheriting too little may be non-viable and the one with too much may be abnormal.

Translocation Where chromosomes of different pairs exchange segments.

Errors in division of centromere Sometimes the centromere divides transversely instead of longitudinally. If the centromere is not central, one of the daughter chromosomes will arise from the two short arms of the parent chromosome and the other from the two long arms. These abnormal daughter chromosomes are called isochromosomes.

These changes have important bearings on heredity, as the e?ect of a gene depends not only upon its nature but also upon its position on the chromosome with reference to other genes. Genes do not act in isolation but against the background of other genes. Each gene normally has its own position on the chromosome, and this corresponds precisely with the positon of its allele on the homologous chromosome of the pair. Each member of a pair of chromosomes will normally carry precisely the same number of genes in exactly the same order. Characteristic clinical syndromes, due to abnormalities of chromosome structure, are less constant than those due to loss or gain of a complete chromosome. This is because the degree of deletion, inversion and duplication is inconstant. However, translocation between chromosomes 15 and 21 of the parent is associated with a familial form of mongolism (see DOWN’S (DOWN) SYNDROME) in the o?spring, and deletion of part of an X chromosome may result in TURNER’S SYNDROME.

Non-disjunction Whilst alterations in the structure of chromosomes arise as a result of deletion or translocation, alterations in the number of chromosomes usually arise as a result of non-disjunction occurring during maturation of the parental gametes (germ cells). The two chromosomes of each pair (homologous chromosomes) may fail to come together at the beginning of meiosis and continue to lie free. If one chromosome then passes to each pole of the spindle, normal gametes may result; but if both chromosomes pass to one pole and neither to the other, two kinds of abnormal gametes will be produced. One kind of gamete will contain both chromosomes of the pair, and the other gamete will contain neither. Whilst this results in serious disease when the autosomes are involved, the loss or gain of sex chromosomes seems to be well tolerated. The loss of an autosome is incompatible with life and the malformation produced by a gain of an autosome is proportional to the size of the extra chromosome carried.

Only a few instances of a gain of an autosome are known. An additional chromosome 21 (one of the smallest autosomes) results in mongolism, and trisomy of chromosome 13 and 18 is associated with severe mental, skeletal and congenital cardiac defects. Diseases resulting from a gain of a sex chromosome are not as severe. A normal ovum contains 22 autosomes and an X sex chromosome. A normal sperm contains 22 autosomes and either an X or a Y sex chromosome. Thus, as a result of nondisjunction of the X chromosome at the ?rst meiotic division during the formation of female gametes, the ovum may contain two X chromosomes or none at all, whilst in the male the sperm may contain both X and Y chromosomes (XY) or none at all. (See also CHROMOSOMES; GENES.)... Medical Dictionary

SEX EDUCATION

Medical Dictionary

Information given to children and young adults about sexual relationships. Evidence suggests that young people want more information about the emotional aspects of sexual relationships, and about homosexuality and AIDS/HIV. There is growing concern about sexual risk-taking behaviour among adolescents, many of whom feel that sex education was provided too late for them. Although most parents or guardians provide some guidance by the age of 16, friends, magazines, television and ?lms are a more signi?cant source of information. Schools have been targeted as a place to address and possibly limit risky behaviour because they are geared towards increasing knowledge and improving skills, and have a captive audience of young adults. There are concerns that the conditions in schools may not be ideal: class time is limited; teachers are often not trained in handling sensitive subjects; and considerable controversy surrounds teaching about subjects such as homosexuality.

Sex education in schools is regarded as an e?ective way of reducing teenaged pregnancy, especially when linked with contraceptive services. Several studies have shown that it does not cause an increase in sexual activity and may even delay the onset of sexual relationships and lessen the number of partners. Programmes taught by youth agencies may be even more e?ective than those taught in the classroom – possibly because teaching takes place in small groups of volunteer participants, and the programmes are tailored to their target populations. Despite improvements in sex education, the United Kingdom has the highest incidence of teenaged pregnancies in the European Community.

Sex education, including information about AIDS/HIV and other sexually transmitted infections (STIs), is compulsory in all state-maintained secondary schools in England and Wales. The National Curriculum includes only biological aspects of AIDS/HIV, STIs and human sexual behaviour.

All maintained schools must have a written statement of their policy, which is available to parents. The local education authority, governing body and headteacher should ensure that sex education encourages pupils to have due regard to moral considerations and the value of family life. Sex-education policies and practices are monitored by the O?ce for Standards in Education (OFSTED) and the O?ce of HM Chief Inspector of Schools (OHMCI) as part of school inspections.... Medical Dictionary

SEX HORMONES

Medical Dictionary

These HORMONES control the development of primary and secondary sexual characteristics. They also regulate sex-related functions – for example, menstruation and the production of sperm and eggs. The three main types of sex hormone are androgens, or male sex hormones (see ANDROGEN); OESTROGENS, or female sex hormones; and progesterones, which are involved in pregnancy (see PROGESTERONE).... Medical Dictionary

SEX RATIO

Community Health

The ratio of one sex to another. Usually defined as the ratio of males to females.... Community Health

SEX THERAPY

Medical Dictionary

The counselling and treatment of individuals with psychosexual dysfunction (see SEXUAL DYSFUNCTION). Around half of couples experience some type of sexual problem during their relationships, and for most of them the di?culties are psychological. Sexual therapy is usually given to both partners, but sometimes individual counselling is necessary. Couples may sometimes ?nd that group therapy is helpful. Therapy has proved e?ective especially for women with VAGINISMUS (spasm of vaginal muscles), men with PREMATURE EJACULATION or IMPOTENCE, and men and women who fail to achieve ORGASM.... Medical Dictionary

SEX-LINKED INHERITANCE

Medical Dictionary

The way in which a characteristic or an illness determined by the SEX CHROMOSOMES in an individual’s cells is passed on to the succeeding generation. Men have one X and one Y sex chromosome and women have two X chromosomes. Disorders that result from an abnormal number of sex chromosomes include KLINEFELTER’S SYNDROME, which a?ects only men, and TURNER’S SYNDROME, which a?ects mainly women. Recessive GENES on the X chromosome cause most other sex-linked characteristics; in women these may well be masked because one of their two X chromosomes carries a normal (dominant) gene. In men, who have just one X chromosome, no such masking occurs – so more men than women are a?ected by X-linked characteristics or diseases. (See also HEREDITY.)... Medical Dictionary

SEXUAL ABUSE

Medical Dictionary

See CHILD ABUSE.... Medical Dictionary

SEXUAL DEVIATION

Medical Dictionary

Any type of pleasurable sexual practice which society regards as abnormal. Deviation may be related to the activity, such as EXHIBITIONISM or sadomasochistic sex (see SADISM; MASOCHISM); or to the sexual object, for example, shoes or clothes (fetishism). Di?erent cultures have di?erent values, and treatment is probably not required unless the deviation is antisocial or harmful to the participant(s). Aversion therapy, or the conditioning of a person’s behaviour, may help if treatment is considered necessary.... Medical Dictionary

SEXUAL DYSFUNCTION

Medical Dictionary

Inadequate sexual response may be due to a lack of sexual desire (LIBIDO) or to an inadequate performance; or it may be that there is a lack of satisfaction or ORGASM. Lack of sexual desire may be due to any generalised illness or endocrine disorder, or to the taking of drugs that antagonise endocrine function (see ENDOCRINE GLANDS). Disorders of performance in men can occur during arousal, penetration and EJACULATION. In the female, DYSPAREUNIA and VAGINISMUS are the main disorders of performance. DIABETES MELLITUS can cause a neuropathy which results in loss of erection. IMPOTENCE can follow nerve damage from operations on the PROSTATE GLAND and lower bowel, and can be the result of neurological diseases a?ecting the autonomic system (see NERVOUS SYSTEM). Disorders of satisfaction include, in men, impotence, emission without forceful ejaculation and pleasureless ejaculation. In women such disorders range from the absence of the congestive genital response to absence of orgasm. Erectile dysfunction in men can sometimes be treated with SILDENAFIL CITRATE (Viagra®), a drug that recent research suggests may also be helpful to women with reduced libido and/or inability to achieve orgasm.

Sexual dysfunction may be due to physical or psychiatric disease, or it may be the result of the administration of drugs. The main group of drugs likely to cause sexual problems are the ANTICONVULSANTS, the ANTIHYPERTENSIVE DRUGS, and drugs such as metoclopramide that induce HYPERPROLACTINAEMIA. The benzodiazepine TRANQUILLISERS can reduce libido and cause failure of erection. Tricyclic ANTIDEPRESSANT DRUGS may cause failure of erection and clomipramine may delay or abolish ejaculation by blockade of alpha-adrenergic receptors. The MONOAMINE OXIDASE INHIBITORS (MAOIS) often inhibit ejaculation. The PHENOTHIAZINES reduce sexual desire and arousal and may cause di?culty in maintaining an erection. The antihypertensive drug, methyldopa, causes impotence in over 20 per cent of patients on large doses. The beta-adrenoceptorblockers and the DIURETICS can also cause impotence. The main psychiatric causes of sexual dysfunction include stress, depression and guilt.... Medical Dictionary

SEXUALLY TRANSMITTED DISEASES (STDS)

Medical Dictionary

Sexually transmitted diseases – traditionally called venereal diseases – are infections transmitted by sexual intercourse (heterosexual and homosexual). In the United Kingdom they are treated in genito-urinary medicine (GUM) clinics. The incidences of these diseases are more common among people who have several sexual partners, as STDs are very infectious; some of the major STDs, particularly AIDS/HIV, are also transmitted by blood and so can result from needle-sharing by drug addicts, or by TRANSFUSION. The ‘traditional’ STDs – SYPHILIS, GONORRHOEA and CHANCROID – now comprise only 10 per cent of all such diseases treated in STD clinics: these clinics also treat patients with CHLAMYDIA, TRICHOMONIASIS, HERPES GENITALIS, MOLLUSCUM CONTAGIOSUM and genital WARTS. SCABIES and pubic lice (see PEDICULOSIS – Pediculus pubis) can also be transmitted by sexual intercourse, and HEPATITIS B is also recognised as an STD.

The incidence of STDs rose sharply during World War II but the advent of PENICILLIN and subsequent antibiotics meant that syphilis and gonorrhoea could be treated e?ectively. The arrival of oral contraception and more tolerant public attitudes to sexual activities resulted in an increase in the incidence of sexually transmitted infections. The diagnosis of NONSPECIFIC URETHRITIS (NSU), once given to many patients whose symptoms were not due to the traditional recognised infections, was in the 1970s realised to be wrong, as the condition was proved to be the result of infection by chlamydia.

Most STDs are treatable, but herpes is an infection that could become chronic, while hepatitis B and, of course, AIDS/HIV are potentially fatal – although treatment of HIV is now proving more e?ective. As well as the treatment and subsequent monitoring of patients with STDs, one of the important functions of clinics has been the tracing, treatment and follow-up of sexual contacts of infected individuals, a procedure that is conducted con?dentially.

Apart from AIDS/HIV, the incidence of STDs fell during the 1980s; however in some countries the agents causing syphilis and gonorrhoea began to develop resistance to antibiotics, which showed the continued importance of practising safe sex – in particular by restricting the number of sexual partners and ensuring the regular use of condoms. In the United Kingdom the rates per million of the male population infected by syphilis rose from 8.8 in 1991 to 9.7 in 1999; in females the ?gures were 4.0 to 4.5, respectively. For gonorrhoea, the ?gures for men were 399.4 in 1991 and 385 in 1999, with women also showing a reduction, from

216.5 to 171.3. In 1991, 552.6 per million of men had chlamydia, a ?gure which rose to

829.5 in 1999; for women in the same period the incidence also rose, from 622.5 to 1,077.1 per million. For genital herpes simplex virus, the infection rate for men fell from 236.6 per million to 227.7, whereas the ?gures for women showed a rise, 258.5 to 357. The incidence of AIDS/HIV is given under the relevant entry. (These ?gures are based on information in United Kingdom Health Statistics, 2001 edition, UKHSI, published by the O?ce of National Statistics.)... Medical Dictionary

TRANS-SEXUALISM

Medical Dictionary

The psycho-sexual condition characterised by feelings of belonging to the gender opposite to that of the genitalia and the secondary sex characteristics. Subjects may be helped by counselling, drug therapy and in some circumstances an operation to change their physical sexual characteristics. Trans-sexuals or their families wanting help and guidance should contact the Gender Identity Consultancy.... Medical Dictionary