Galactorrhea is where there is abnormal milk secretions from the breast. Both genders may be affected and may be a side effect of some medications such as antipsychotics.
Galactosemia
Galactosemia is a rare genetic metabolic disorder which affects proper metabolism of the sugar galactose.
Gallbladder
The gallbladder is a pear shaped gastrointestinal organ situated just below the liver. The gallbladder's main function is the storage and concentration of bile. Bile is a yellow-green substance that helps break down fats in the intestines.
Gallstones/ Gall Stones
Gallstones are solid "stones" which are formed within the gallbladder, an organ that stores bile excreted from the liver. Bile is made up of water, salts, lecithin, cholesterol, and other substances. If the concentration of the components changes, gallstones may form. Gallstones may be small or large, depending on how long they have been forming.
Gamete
Sex cells, that is the cells which can be fertilised by gametes of the opposite sex. In females gametes are known as eggs, oocytes or ovum. In males gametes are known as sperm or spermatozoa.
Gardener's syndrome involves the development of multiple tumours in soft and hard tissues of the body.
Gardner's Syndrome
Autosomal dominant variant of familial adenomatous polyposis, caused by mutations in the APC gene. Features include multiple premalignant colon polyps, benign bone exostoses, epidermal cysts, dermoid tumours, fibromas and neurofibromas. Onset: around 20 years of age.
Gastric banding is a common type of surgery for weight loss. It is usually performed laparoscopically (via key-hole surgery). Gastric banding involves placing an adjustable silicone band around the stomach. This acts similarly to a tight belt and reduces the capacity of the stomach. Reductions in meal sizes can lead to weight loss.
Gastric bypass
Gastric bypass is a type of surgery for weight loss which may be used to treat obesity. during the procedure a small pouch is created in the stomach which is connected to further along the small intestine. (refer to anatomy and physiology of the gastrointestinal system for further information). Food can thus bypass or divert away from parts of the stomach and intestines. This reduces absorption of fats and calories (causing weight loss) but can also lead to reduced absorption of important nutirents (malnutrition).
Gastric Tube
A gastric tube is a tube inserted into the stomach to feed patients who cannot take food through their mouths.
Gastric Ulcers
A Gastric Ulcer is a break in the tissue lining the stomach. The term 'peptic ulcer' refers to those that occur in either the stomach or the first part of the small intestine that leads out of the stomach, called the duodenum. It was once commonly thought that stress, smoking and diet were the principal causes of stomach ulcers.
Gastrocnemius Muscle
The gastrocnemius muscle is the major calf muscle, and controls flexing of the ankle and knee.
Gastrointestinal
Gastrointestinal means pertaining to the stomach or intestinal systems.
Gastro-oesophageal reflux disease (also known as gastroesophageal reflux disease, GORD, GERD or acid reflux disease) is a disease of the lower oesophagus and stomach. It involves the inflammation of the lower oesophagus due to the reflux of gastric juice and/or bile.
Gastroparesis
Gastroparesis; also known as delayed gastric emptying, results in food being in the stomach for much longer than normal. It is caused by muscle or nerve damage and results in symptoms such as bloating and belching.
Gastroplasty
Gastroplasty (also known as gastric stapling) is a surgical procedure for weight loss. It basically involves stapling the stomach to form a small pouch. This reduces the amount of food that can be taken into the stomach and eventually leads to loss of weight.
Gastrulation is a process of cell migration through which the flat two layered embryo becomes a flat three layered embryo.
Gate control theory
The gate control theory is a theory explaining how pain is produced and experienced by the body. This theory suggests that pain is stimulated by noxious (harmful) stimuli at nerve endings. However, the body has a "gate" which it can "shut" to stop the flow of these noxious stimuli and hence stop the sensation of pain. By stimulating nerves it is possible to artificially cause this "gate" to close and hence stop the sensation of pain in the stimulated regions.
Gating
Gating, in relation to pain, is a normal regulatory mechanism which affects the way we perceive pain.In the spinal cord, normal (non-pain) sensory fibres are linked to pain fibres in such a way that one can suppress the other. For example, after stubbing your toe (a painful stimulus), gently rubbing the skin over the toe (non-pain sensation) can reduce the feeling of pain. The non-pain sensation takes over and inhibits the transmission of the pain sensation.
Gaucher disease
Gaucher disease is a lysosomal storage disorder that is autosomal recessive and is characterised by a deficiency in the lysosomal enzyme glucocerebrosidase that is required in the breakdown of the glycolipid glucocerebroside (glucosylceramide).
Gelclair is a medical device used to reduce pain in patients with oral mucositis or other conditions that cause damage to the mucous membranes of the mouth. It is administered as a solution which is rinsed in the mouth. The solution adheres to the gums, tongue and other mucous membranes, creating a physical barrier that protects the damaged membranes from irritation.
A gene is the master instruction that describes to a cell how to make a particular molecule. Since our entire body is made up of molecules of one kind or another, genes can have very profound effects on what our body does and how it does it. A gene is stored in the cell using a substance called DNA. People get their genes from a mixing of their parents' genes. Genes even describe how to make the cells reading the genes - this sounds very confusing, even impossible! However, the body solves it by starting life with special cell called an egg, which comes with some of the reading equipment ready-made.
Gene Sequence
A gene sequence is a stretch of DNA in a specific location on a chromosome that codes for a gene.
Gene therapy
Gene therapy involves the alteration of DNA to correct or prevent disease by inserting a gene artificially into the genome of an organism to correct a genetic defect.
General Anaesthesia
General Anaesthesia: This is a type of anaesthesia in which a patient feels nothing due to drugs called 'general anaesthetics'. In a conscious state, the brain constantly receives information from nerves throughout the body - these drugs stop the brain from properly understanding these signals, and so they cause a state of unconsciousness. When these drugs wear off, consciousness returns. While anaesthetised, a patient can be given other drugs to relax muscles, manage pain, and control the patient's condition. A general anaesthetic is given by a specialist doctor called an anaesthetist, who monitors the patient's condition while they are unconscious.
General anaesthetic
A General anaesthetic is a drug used to bring about a reversible loss of consciousness. General anaesthetics can be inhaled or injected into the blood supply and are most commonly used to facilitate a surgical procedure.
Generalise
In psychotherapy when clients are said to effectively generalise this is referring to their ability to adapt what they have learnt in their psychotherapy sessins to different settings, situations and people other than their psychologist. How well the client can generalise their new behaviours, skills and thoughts is the best indicator of psychotherapeutic effectiveness.
Generalised Dystonia
Generalised dystonia describes dystonia that is widespread and involves debilitating muscle contractions throughout most or all of the body.
A generic drug is a copy of the original branded drug.
Once the patent for the original product has run out, the pharmaceutical company who developed the branded drug no longer has the exclusive right to produce and distribute the medication, and other pharmaceutical companies are able to create their own version.
The generic drug uses the same active ingredient as in the original product, but the inactive ingredients are slightly different, the brand name will be different and the drug may look different.
If someone is said to have a genetic predisposition to a particular medical condition, disease or disorder it means that they may inherit the condition from relatives due to the passing on of DNA from one generation to the next.
Genetic testing
Genetic testing involves the analysis of human tissue to identify genetic disorders. Further information can be found in the investigations section: Genetic testing for hereditary disorders.
Genital Discharge
Genital discharges are secretions from the penis or vagina. Many discharges occur normally, but discharges which are smelly or unusually coloured are commonly associated with sexually transmitted infections.
Genital Herpes
Genital herpes is a viral infection that is transmitted through sexual contact caused by herpes simplex 1 or 2. Symptoms include burning, tingling and itching followed by blisters which can be painful. These occur around the genital area
Genital warts
Genital warts are lesions that are found in the genital area. They can occur in both males and females, and are transmitted via Human Papillomavirus (HPV), mainly through sexual contact with an infected person.
Genitopelvic contractions
Genitopelvic contractions are contractions of the muscles of the genitals and pelvis.
Genome
The genome of an organism is its entire genetic information, encoded by DNA (this includes all genes and DNA that does not encode genes).
German measles (or Rubella) is a viral illness which may produce a rash, swollen glands, joint pain and muscle pains in infected children or adults. Though most infections are mild, the real danger of rubella infection lies in the risk of Congenital Rubella Syndrome, which may occur if a non-immune pregnant woman becomes infected during the first half of pregnancy. This can have devastating consequences for the baby, which may be born deaf, blind, with heart defects, or mentally retarded.Children and adults can be protected against rubella infection through immunisation.
Gestation
Gestation can be used to refer to the period of time between conception and birth or the length of time of the pregnancy.
Gestational trophoblastic neoplasia are malignant (i.e. cancerous) forms of gestational trophoblastic disease, also known as gestational trophoblastic tumours.
Gestational trophoblastic tumours
Gestational trophoblastic tumours are malignant (i.e. cancerous) forms of gestational trophoblastic disease, also known as gestational trophoblastic neoplasia.
Giant papillary conjunctivitis refers to a conjunctival reaction in response to a foreign body (commonly contact lenses) causing prolonged mechanical irritation.
An unhealthy condition of the gums where they are red and overgrown.
Gingivitis
Gingivitis refers to inflammation of the gingiva (gums), and is seen as painless bleeding during brushing and flossing. Gingivitis is considered the start of gum disease, and can be resolved relatively simply if good dental hygiene is practiced.
Ginseng
Ginseng (Panax ginseng) is an Asian herb used as a natural remedy. It has been used in the treatment of menopausal symptoms and there is some evidence that it is effective in reducing cognitive decline and improving physical health and sexual function. However it has not been demonstrated effective in relieving menopausal hot flushes.
Glabellar Lines
Glabellar lines are vertical wrinkles on the forehead, between the eyebrows.
Gland
A Gland refers to a group of cells organised in such a way that the products synthesised by the individual cells (secretions) are released either locally via ducts (exocrine glands) or into the blood stream (endocrine glands) to have effects at distant sites
Gland
A gland is a group of cells that all create the same substance (usually a fluid) either for use in or outside of the body. There are two types of glands: exocrine glands and endocrine glands.
Glans penis
The glans penis is the enlarged tip (head) of the penis.
Glanzmann's thrombasthenia
Glanzmann's thrombasthenia is a rare inheritable disease in which the body's normal blood clotting system has a defect characterised by a problem with platelet-mediated haemostasis, and blood does not clot. This can lead to excessive and unwarranted bleeding.
Glass-ionomer cements
Glass-ionomer cements are a type of filling material used in dentistry, which have a range of uses e.g. fillings, cementing crowns, protective material under fillings etc. When glass particles are mixed with a weak acid, there is a reaction that causes it to harden like cement. They do contain fluoride, which makes them prone to secondary decay around the filling. Unfortunately, they are one of the weaker types of filling materials.
Glaucoma
Glaucoma is a leading cause of blindness. It usually occurs when the fluid pressure inside the eyes slowly rises, damaging the optic nerve. Often there are no symptoms at first, but a comprehensive eye exam can detect it and early treatment can help protect against vision loss.
The Gleason score is a method of tumour classification used to classify the cancer into a stage which indicates how severe the cancer is and how likely it is that the treatment will be successful. The Gleason score is used to classify prostate cancer.
A numerical score is given to a cancer, from 2 to 10, which is the sum of two Gleason grades (depending on the level of changes the cells in the prostate cancer show). The Gleason score helps determine if a patient is suitable for high intensity focused ultrasound.
Glenohumeral ligaments
There are three glenohumeral ligaments which provide some support to the front of the shoulder joint; the superior, middle and anterior inferior. The superior glenohumeral ligament works in conjunction with the coracohumeral ligament to stabilise the humeral head. The middle glenohumeral ligament is not always present. When it is present, it aids to stabilise the humeral head. The thick inferior ligament is the primary stabiliser of the three.
The glenoid cavity is the part of the scapula (shoulder blade) that forms the socket for the ball (humeral head) The glenoid cavity is relatively shallow but is made deeper by a rim of fibrocartilage called the glenoid labrum, that runs around its periphery and effectively doubles the depth of the socket. The glenoid is a relatively shallow joint compared with for example the hip socket. This allows for the unparalleled flexibility of the shoulder, but also predisposes the joint to instability - the shoulder is the most frequently dislocated joint in the body.
In addition to neurons, glial cells are the other major type of cells that make up the nervous system. They are also called neuroglia. Glial cells serve to protect and nourish the neurons. Neurons depend on glial cells to grow, nourish themselves, and establish effective synapses.
Glomerular Filtration Rate (GFR) is a measure of the rate at which kidneys filter fluids. The GFR provides an indication of the underlying kidney function, hence is useful for the diagnosis and testing of kidney disease. 2.The glomerular filtration rate (GFR) is the rate at which an ultrafiltrate of plasma is produced by glomeruli per unit of time. The GFR gives the best estimate of the number of functioning nephrons or functional renal mass.
Glottis
The glottis forms the entrance to the larynx (voicebox) and is made up of the vocal cords and the space between them.
Glucocorticoids
This group of medications refers to a group of steroid hormones, produced by glands located on top of your kidneys, known as adrenal glands. Glucocorticoids can be used in conjunction with bronchodilators, to achieve effective control of lung diseases.
Glucose
Glucose, sometimes referred to as dextrose, is a simple sugar available in its free form in fruits and plants. It also occurs in the blood, where it is the main supply of energy for most human cells. In Diabetes Mellitus, levels in the blood are usually high, and may appear in the urine. Glucose in the blood is obtained from the breakdown of food in the digestive system.
Glucose intolerance
Glucose intolerance is low levels of insulin, or failure of the body to respond to insulin, despite high levels of glucose. Glucose can not be taken up from the blood and used in the cells, so blood glucose (sugar) levels remain high.
Glucose utilisation
Glucose utilisation is the amount of glucose that is used for energy requiring processes in the body. When energy needs are high, glucose utilisation will be active.
Glucose-6-phosphate dehydrogenase deficiency
Glucose-6-phosphate dehydrogenase deficiency is an x-linked recessive genetic disease where the individual has very low levels of the enzyme, glucose-6-phosphate dehydrogenase (G6PD). This enzyme is involved in red blood cell metabolism.
Glucose-6-phosphate dehydrogenase defiency
Glucose-6-phosphate dehydrogenase deficiency is an x-linked recessive genetic disease where the individual has very low levels of the enzyme, glucose-6-phosphate dehydrogenase (G6PD). This enzyme is involved in red blood cell metabolism.
Glutamine
Glutamine is a non-essential amino acid, which plays numerous roles in the metabolic process. It can however cause intolerance in sensitive individuals.
Glutathione
Glutathione is an endogenous antioxidant, that is, an antioxidant which is produced by the body (as opposed to consumed through the diet).
Gluteal Fat
Gluteal fat is fat that is stored around the hips and buttocks.
Gluteal Muscle
The gluteal muscles are the muscles that form the buttocks and control movement of the thighs.
Gluten
Gluten is a storage protein derived from wheat, barley, rye and a number of other cereals.
Gluten Free Diet
A gluten free diet is a diet in which all sources of the protein gluten are excluded. Practically, this means excluding wheat, rye, barley and a number of other cereals and their derivatives.
The Glycaemic Index (GI) is a numerical index assigned to a food. It is obtained by measuring the effect that a carbohydrate containing food has on blood sugar levels, compared to the effect of the same amount of pure sugar, on blood sugar levels.
Glycaemic Load
The Glycaemic Load (GL) is defined as a system for ranking the carbohydrate content in food products based on the Glycaemic Index (GI) and serving size. It is determined by multiplying the GI value of the food by the carbohydrate content of the food.This provides us with a more accurate picture of the overall effect that the food product has on blood sugar levels.
Glycans
Glycan refers to a polysaccharide, or oligosaccharide. Glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein.
Glycated haemoglobin
This level can give us an indication of overall diabetes control and average blood sugar control within the last 2-3 months. The usefulness of the glycated haemoglobin lies in the fact that glucose molecules will permanently attach themselves to haemoglobin molecules and the level of haemoglobin affected can be measured in the blood.
Glyceryl trinitrate
Glyceryl trinitrate is a medication used to provide temporary relief from angina.
Glycogen
Glycogen is the main energy storage carbohydrate in the body.
Glycol ether
Glycol ethers are a group of solvents. They are most commonly found as ingredients in paint.
Glycolipid
Glycolipids are polar macromolecules that comprise a non-polar fatty acid and a polar carbohydrate molecule. Glycolipids, amongst other roles, form the membranes of cells.
Glycolysis
Glycolysis is the process through which the body breaks down sugars and carbohydrates into energy which can be used by the body.
Glycopeptides
Antibiotics that fall within this group include: Vancomycin and Teicoplanin. These drugs act by preventing the bacteriafrom making the walls of their cells and also by impairing synthesis of RNA. Both antibiotics are very active against resistant Gram positive organisms. However, they have poorer activity against Gram negative bacteria.
Glycosuria is a condition characterised by excessive glucose in the urine. It is often a symptom of diabetes mellitus.
Goitre
Goitre is a condition characterised by abnormal enlargement of the thyroid gland, which is often visible as a growth on the neck. It is commonly associated with deficiency in the micronutrient iodine.
Gomphosis (dentoalveolar syndesmosis) consists of a bone with processes (tooth) that slot into an articulation socket, producing a joint which is immobile.
Gonadotroph
A gonadotroph is a specific cell (basophilic cell) which secretes follicle-stimulating hormone or luteinising hormone from the anterior pituitary.
Gonadotrophin Releasing Hormone (GnRH)
Gonadotrophin Releasing Hormone (GnRH) is a hormone that is responsible for the stimulation of specific cells called gonadotrophs in the pituitary gland. This stimulation results in the production of two important hormones called LH (luteinising hormone) and FSH (follicular stimulating hormone) from the pituitary. GnRH is of great importance in the menstrual cycle. One of the most important features of GnRH release is the fact that its release occurs in a pulsatile fashion. At the start of puberty there is a marked increase in the frequency and amplitude of GnRH release.
The Gordon Diagnostic System is a series of game-like tests that assess both attention and impulsivity. The system includes a "vigilance task", which shows the child a series of digits, one at a time. The child must identify every time a particular sequence of numbers appear (e.g. a 1 followed by a 9). This test is performed once visually, and once with the child listening to the numbers. There is also a test to check for impulsivity. The Gordon Diagnostic System has been validated for children between the ages of 4 and 16.
GPR - Good partial remission
A reduction in more than 75% of the tumour mass.
Graafian follicle
The graafian follicle forms in the adult ovary. There is proliferation of the granulosa cells with the formation of a fluid filled cavity called the antrum. The granulosa cells nearest the zona pellucida form the corona radiata, which is released as a part of the oocyte during ovulation. The Graafian follicle is the chosen follicle, and the remaining follicles undergo atresia.
Graft-versus-host disease (GVHD)
Graft-versus-host disease (GVHD) is a common complication of allogeneic bone marrow transplantation in which the transplanted marrow recognise the recipient as "foreign" and mount an immunologic attack.
Granulocyte
A granulocyte is a type of white blood cell and part of the immune system that when looked at under a microscope seems to have lots of little granules of substances inside them. The type of granules determine what type of cell it is. They are divided into three types: neutrophils, basophils and eosinophils.
Granulocyte-CSF (G-CSF)
Granulocyte-CSF (G-CSF) is a protein which interacts with receptors on the surface of primitive bone marrow cells. Granulocyte-CSF (G-CSF) stimulate them to produce adult cells.
Granulocyte-macrophage colony stimulating factor (GM-CSF) is a protein which interacts with receptors on the surface of the primitive bone marrow cells. Granulocyte-macrophage colony stimulating factor stimulates them to produce adult cells.
Granulosa cells
Granulosa cells are oestrogen-secreting cells that help nourish the oocyte during its development by releasing estradiol. After ovulation the granulosa cells become luteal cells of the corpus luteum that produce progesterone. The release of this hormone from the corpus luteum helps maintain pregnancy in women and also produces a thick cervical mucus which inhibits sperm into the uterus.
Graves' Ophthalmopathy (Thyroid Eye Disease)
Graves' ophthalmopathy is an eye disorder found in individuals with Graves' disease. It is characterised by inflammation of the eye and fat in the eye socket. In severe cases inflammation can compress the optic nerve, leading to blindness. The condition is also known as thyroid eye disease.
Greater tuberosity
The greater tuberosity of the shoulder is site of insertion of three important shoulder (rotator cuff) muscles; the supraspinatus, infraspinatus and teres minor.
Grey matter makes up part of the central nervous system and is mainly made up of cell bodies and dendrites. It is called grey matter because it has a grey appearance in fresh material.
Growth factors
Growth factors are those agents that stimulate epithelial proliferation. It can refer to medication or even naturally occurring substances in the body (usually proteins or steroids). They are important in maintaining cellular processes.
Growth Hormone
Growth hormone is a hormone produced by the pituitary gland. It plays a key role in the body's growth and development. An excess of growth hormone leads to the condition known as acromegaly, or gigantism. Artificial growth hormone may be administered as a drug in order to treat certain medical conditions (such as obesity).
Guillain-Barre syndrome
Guillain-Barre syndrome refers to an infection which usually affects the respiratory tract. It causes general weakness and frequently the affected muscles become paralysed.
Guttate Psoriasis
Guttate psoriasis is a form of psoriasis that appears as small (less than 1 cm diameter) salmon-pink 'dewdrop' papules (small plaques), usually covered with a fine scale, which erupt on the trunk and upper arms and legs, about 2–3 weeks after a viral or bacterialupper respiratory infection such as tonsillitis.
Guttate psoriasis tends to occur in childhood and early adulthood (before the age of 30).
The shape of a female's body is referred to as gynacoid, or "pear-shaped". This shape describes the distribution of body fat on the hips and thighs as a pose to males who carry weight in the abdominal region. Male's bodies are described as android or "apple-shaped". Females on average naturally have a higher total and percentage of body fat than men.
Gynaecologist
A gynaecologist is a medical doctor who specialises in treating diseases particular to women.
Gynaecomastia
Gynaecomastia is a medical term used to refer to excessive breast growth in males.
Gyrus
A gyrus (pl. gyri) is defined as an elevation or "hill" on the surface of the brain. A gyrus is generally surrounded by one or more sulci.
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