A

• Abdomen - the part of the body between the pelvis and the thorax containing the stomach, intestines, liver, spleen, pancreas etc.

• Abduction - movement away from the midline off the bodyAcid mantle - a protective film covering the skin, which consists of sebum and sweat and protects the skin by inhibiting the growth of bacteria and other organisms

• Abrasion - the act of scrubbing or wearing away or a scrape in the skin as a result of injury

• Absorption - the taking in of a substance such as liquid or gas

• Accident - an unfortunate event or occurrence that happens unintentionally and results in harm, injury or damage

• Acid mantle - a combination of sebum secreted by the sebaceous glands and sweat excreted by the sweat glands in the skin, it has a pH between 4 and 5.5

• Acne - inflammation of sebaceous glands usually begins at puberty and is characterised by oily skin, comedones, papules, pustules, cysts and in severe cases nodules

• Acne rosacea - a skin disorder affecting parts of the face, most commonly across the cheeks and nose and down the centre panel from the forehaed to the chin. It is characterised by redness, papules, pustules, thickened skin, broken capillaries and sometimes dry eyes and soreness of the eyelids. It is a condition that often begins in  middle age

• Acromegaly - condition of the endocrine system caused by an over secretion of growth hormone

• Acrylic - a polymerised polymer coating used to form an artificial nail

• Addisons disease - disorder of the endocrine system caused by hyposecretion of glucocorticoids

• Adduction - movement towards the midline of the body

• Adhesive - a chemical or glue that allows two surfaces to stick together

• Adrenal glands - endocrine glands situated above the kidneys

• Adrenalin - hormone produced by the adrenal glands in response to stress

• Afferent - moving inward or towards an organ or a body part

• Airbrush - hand held applicator to administer a fine spray of makeup to the face and body, or paint to the nails in nail art

• Allergen - an antigen that causes a hypersensitive reaction

• Allergic reaction- sensitivity to an allergen causing; redness, itching, blisters and localised swelling 

• Alternating current - an electrical current that reverses direction in a circuit at regular intervals

• Alveoli - tiny air sacs in the lungs where the interchange of gases takes place

• Amenorrhoea - absence of menstruation

• Ampere - strength of electrical current

• Anagen - the growth phase of a hair follicle

• Anatomy - the bodily structure

• Androgens - hormones that produce male characteristics e.g. testosterone

• Anion - a negatively charged ion, an atom that has more protons than electrons and migrates towards the anode in electrolysis

• Anode - a positively charged electrode by which electrons leave an electrical device, the positive pole in galvanism

• Anorexia nervosa - a disorder characterised by loss of appetite and bizarre eating patterns

• Anterior - front

• Antibody - a substance produced by certain cells to neutralise or destroy an antigen

• Antidiuretic hormone - hormone produced in the pituitary gland to control water levels in the body

• Antigen - a substance that stimulates the production of antibodies

• Antioxidants - a compound that inhibits oxidation such as vitamins C, E or Beta carotene and protects the body from free radical damage

• Antiseptic - a substance that inhibits the growth of bacteria

• Apocrine glands - sweat glands that occur on hairy parts of the body especially armpits and groin

• Aponeurosis - a sheet like layer of connective tissue joining one muscle with another or with bone

• Appendix - a narrow blind tube, having no known useful function, protruding from the caecum in the digestive system  

• Aromatherapy - the use of essential oils to affect mood and promote wellbeing

• Arrector pili - smooth muscle attached to hair

• Arteriole - small arterial branch that delivers blood to the capillaries.

• Artery - a blood vessel that carries blood away from the heart

• Aseptic - free from infection and organisms that cause disease

• Atom - a unit of matter that comprises a chemical element and consists of a nucleus and electrons

• Atonic - relating to, caused by or exhibiting a lack of muscle tone or lacking energy

• Atrophy - wasting away or decreasing in size

• Audio sonic - a hand held sound wave vibrator used to gently massage the tissues

• Auditory canal - the internal part of the ear

• Aura - human energy field

• Aural - by ear

• Autoclave - equipment used to sterilise small metal instruments

• Autonomic nervous system - part of the nervous system responsible for automatic functions and consisting of the sympathetic and parasympathetic systems

• Axilla - the armpit

• Axon - the process of a nerve cell that carries an impulse away from the cell body

• Ayurveda - the ancient Hindu science of health and medicine