Glossary

Browse through glands, hormones and endocrine conditions.
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R

radiation

energy waves emitted from a radioactive or other source, which can cause tissue damage at high levels. Patients are exposed to low amounts of radiation during most types of medical scans.

radioactive

describes a material that gives out ionising radiation – alpha, beta or gamma rays – which can cause damage to body tissues.

radioiodine

a molecule of iodine that is labelled or tagged with a radioactive substance. Radioiodine treatment is used in thyroid conditions to gradually destroy overactive thyroid tissue.

radiologist

a medical professional who is trained to carry out specialist scans of the body, such as MRI, CT and ultrasound scans.

reabsorption

the taking back in of a substance that was previously released into the body. This process occurs in the kidney, where the blood is filtered and useful substances are reabsorbed back into the blood.

receptor antagonists

drugs with the same structure as a signalling molecule naturally produced by the body, with both competing for the same receptor. The antagonists block these receptors and stop the naturally occurring signalling molecules from working.

receptors

(on cells) – proteins attached to the outside membrane of cells that receive signals from substances, such as hormones, in the bloodstream. This causes a chain of events to occur inside the cell which carry out the action of the hormone.

rehydration

taking in fluids to restore a previous state of dehydration (not taking in enough fluids).

relapse

a setback or reappearance of symptoms of a condition following a period of stability/controlled symptoms.

remission

a state of good health following treatment for a condition.

Relaxin

Relaxin is a hormone produced by the ovary and the placenta with important effects in the female reproductive system and during pregnancy. In preparation for childbirth, it relaxes the ligaments in the pelvis and softens and widens the cervix.

Resistance to thyroid hormone

Resistance to thyroid hormone is a rare genetic condition where some body tissues do not respond normally to thyroid hormones produced by the thyroid gland. It may be associated with no symptoms or with features of both an overactive and underactive thyroid.

Rickets

Rickets is a condition in children where there is abnormal softening of the bones due to the lack of key minerals. It is also known as osteomalacia in adults.


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