Gynaecology or gynecology is the medical practice dealing with the health of the female reproductive system (uterus, vagina, and ovaries). Literally, outside medicine, it means "the science of women". Almost all modern gynaecologists are also obstetricians (see obstetrics and gynaecology). It is the counterpart to andrology, which deals with medical issues specific to the male reproductive system. The Kahun Gynaecological Papyrus is the oldest known medical text of any kind. Dated to about 1800 B.C., it deals with women's complaints—gynaecological diseases, fertility, pregnancy, contraception, etc. The text is divided into thirty-four sections, each section dealing with a specific problem and containing diagnosis and treatment, no prognosis is suggested. Treatments are non surgical, comprising applying medicines to the affected body part or swallowing them. The womb is at times seen as the source of complaints manifesting themselves in other body parts.

According to the Suda, the ancient Greek physician Soranus of Ephesus practised in Alexandria and subsequently Rome. He was the chief representative of the school of physicians known as the "Methodists." His treatise Gynaikeia is extant (together with a 6th-century Latin paraphrase by Muscio, a physician of the same school).

In the United States, J. Marion Sims is considered the father of American gynaecology.

Gynaecology is concerned with the female genital tract and its disorders. In many areas, the specialties of gynaecology and obstetrics overlap. Gynaecology has been considered to end at 28 weeks gestation, but practically there is no clear cut-off.

Since 1st October 1992, this cut-off may be considered to occur at 24 weeks gestation, since the law and definition of abortion changed to bring it closer to the gestation at which a foetus becomes viable.

Gynaecology is typically considered a consultant specialty. In some countries, women must first see a general practitioner (GP; also known as a family practitioner (FP)) prior to seeing a gynaecologist. If their condition requires training, knowledge, surgical technique, or equipment unavailable to the GP, the patient is then referred to a gynaecologist. In the United States, however, law and many health insurance plans allow/force gynaecologists to provide primary care in addition to aspects of their own specialty. With this option available, some women opt to see a gynaecological surgeon without another physician's referral.

As in all of medicine, the main tools of diagnosis are clinical history and examination. Gynaecological examination is quite intimate, more so than a routine physical exam. It also requires unique instrumentation such as the speculum. The speculum consists of two hinged blades of concave metal or plastic which are used to retract the tissues of the vagina and permit examination of the cervix, the lower part of the uterus located within the upper portion of the vagina. Gynaecologists typically do a bimanual examination (one hand on the abdomen and one or two fingers in the vagina) to palpate the cervix, uterus, ovaries and bony pelvis. It is not uncommon to do a rectovaginal examination for complete evaluation of the pelvis, particularly if any suspicious masses are appreciated. Male gynaecologists may have a female chaperone for their examination. An abdominal and/or vaginal ultrasound can be used to confirm any abnormalities appreciated with the bimanual examination or when indicated by the patient's history.

Neural precursors in sponges

Sponges have no cells connected to each other by synaptic junctions, that is, no neurons, and therefore no nervous system. They do, however, have homologs of many genes that play key roles in synaptic function. Recent studies have shown that sponge cells express a group of proteins that cluster together to form a structure resembling a postsynaptic density (the signal-receiving part of a synapse). However, the function of this structure is currently unclear. Although sponge cells do not show synaptic transmission, they do communicate with each other via calcium waves and other impulses, which mediate some simple actions such as whole-body contraction.
Radiata

Jellyfish, comb jellies, and related animals have diffuse nerve nets rather than a central nervous system. In most jellyfish the nerve net is spread more or less evenly across the body; in comb jellies it is concentrated near the mouth. The nerve nets consist of sensory neurons that pick up chemical, tactile, and visual signals, motor neurons that can activate contractions of the body wall, and intermediate neurons that detect patterns of activity in the sensory neurons and send signals to groups of motor neurons as a result. In some cases groups of intermediate neurons are clustered into discrete ganglia.

The development of the nervous system in radiata is relatively unstructured. Unlike bilaterians, radiata only have two primordial cell layers, endoderm and ectoderm. Neurons are generated from a special set of ectodermal precursor cells, which also serve as precursors for every other ectodermal cell type.

At a more integrative level, the primary function of the nervous system is to control the body. It does this by extracting information from the environment using sensory receptors, sending signals that encode this information into the central nervous system, processing the information to determine an appropriate response, and sending output signals to muscles or glands to activate the response. The evolution of a complex nervous system has made it possible for various animal species to have advanced perception abilities such as vision, complex social interactions, rapid coordination of organ systems, and integrated processing of concurrent signals. In humans, the sophistication of the nervous system makes it possible to have language, abstract representation of concepts, transmission of culture, and many other features of human society that would not exist without the human brain.

Neurons and synapses

Most neurons send signals via their axons, although some types are capable of dendrite-to-dendrite communication. (In fact, the types of neurons called amacrine cells have no axons, and communicate only via their dendrites.) Neural signals propagate along an axon in the form of electrochemical waves called action potentials, which produce cell-to-cell signals at points where axon terminals make synaptic contact with other cells.

Synapses may be electrical or chemical. Electrical synapses make direct electrical connections between neurons,but chemical synapses are much more common, and much more diverse in function. At a chemical synapse, the cell that sends signals is called presynaptic, and the cell that receives signals is called postsynaptic. Both the presynaptic and postsynaptic areas are full of molecular machinery that carries out the signalling process. The presynaptic area contains large numbers of tiny spherical vessels called synaptic vesicles, packed with neurotransmitter chemicals. When the presynaptic terminal is electrically stimulated, an array of molecules embedded in the membrane are activated, and cause the contents of the vesicles to be released into the narrow space between the presynaptic and postsynaptic membranes, called the synaptic cleft. The neurotransmitter then binds to receptors embedded in the postsynaptic membrane, causing them to enter an activated state. Depending on the type of receptor, the resulting effect on the postsynaptic cell may be excitatory, inhibitory, or modulatory in more complex ways. For example, release of the neurotransmitter acetylcholine at a synaptic contact between a motor neuron and a muscle cell induces rapid contraction of the muscle cell. The entire synaptic transmission process takes only a fraction of a millisecond, although the effects on the postsynaptic cell may last much longer (even indefinitely, in cases where the synaptic signal leads to the formation of a memory trace).

 

The main conditions dealt with by a gynaecologist are:

1. Cancer and pre-cancerous diseases of the reproductive organs including ovaries, fallopian tubes, uterus, cervix, vagina, and vulva
2. Incontinence of urine.
3. Amenorrhoea (absent menstrual periods)
4. Dysmenorrhoea (painful menstrual periods)
5. Infertility
6. Menorrhagia (heavy menstrual periods). This is a common indication for hysterectomy.
7. Prolapse of pelvic organs
8. Infections (including fungal, bacterial, viral, and protozoal)

There is some crossover in these areas. For example, a woman with urinary incontinence may be referred to a urologist.

As with all surgical specialties, gynaecologists may employ medical or surgical therapies (or many times, both), depending on the exact nature of the problem that they are treating. Pre- and post-operative medical management will often employ many "standard" drug therapies, such as antibiotics, diuretics, antihypertensives, and antiemetics. Additionally, gynaecologists make frequent use of "specialized" hormone-modulating therapies (such as Clomifene citrate and hormonal contraception) to treat disorders of the female genital tract that are responsive to pituitary and/or gonadal signals.
For lists of gynaecological drugs (by the ATC classification system), see ATC code G01 and ATC code G02.

Surgery, however, is the mainstay of gynaecological therapy. For historical and political reasons, gynaecologists were previously not considered "surgeons", although this point has always been the source of some controversy. Modern advancements in both general surgery and gynaecology, however, have blurred many of the once rigid lines of distinction. The rise of sub-specialties within gynaecology which are primarily surgical in nature (for example urogynaecology and gynaecological oncology) have strengthened the reputations of gynaecologists as surgical practitioners, and many surgeons and surgical societies have come to view gynaecologists as comrades of sorts. As proof of this changing attitude, gynaecologists are now eligible for fellowship in both the American College of Surgeons and Royal Colleges of Surgeons, and many newer surgical textbooks include chapters on (at least basic) gynaecological surgery.

Some of the more common operations that gynaecologists perform include:

1. Dilation and curettage (removal of the uterine contents for various reasons, including partial miscarriage and dysfunctional uterine bleeding refractive to medical therapy)
2. Hysterectomy (removal of the uterus)
3. Oophorectomy (removal of the ovaries)
4. Tubal ligation
5. Hysteroscopy
6. Diagnostic laparoscopy – used to diagnose and treat sources of pelvic and abdominal pain; perhaps most famously used to provide definitive diagnosis of endometriosis.
7. Exploratory laparotomy – may be used to investigate the level of progression of benign or malignant disease, or to assess and repair damage to the pelvic organs.
8. Various surgical treatments for urinary incontinence, including cystoscopy and sub-urethral slings.
9. Surgical treatment of pelvic organ prolapse, including correction of cystocele and rectocele.
10. Appendectomy – often performed to remove site of painful endometriosis implantation and/or prophylactically (against future acute appendicitis) at the time of hysterectomy or Caesarean section. May also be performed as part of a staging operation for ovarian cancer.
11. Cervical Excision Procedures (including cryosurgery) – removal of the surface of the cervix containing pre-cancerous cells which have been previously identified on Pap smear.