by Hannah Farrell
Our Expert Witnesses in Endocrinology specialise in the diagnosis and management of conditions of the endocrine system. They are experts in the treatment of hormonal disturbances and the management of conditions affecting the hypothalamus, pituitary gland, thyroid, adrenal glands, and pancreas. They have a profound knowledge of managing conditions such as Cushing’s disease, Addison’s disease, and thyrotoxicosis.
With a strong understanding of appropriate standards of care and NICE Guidelines, in addition to a thorough knowledge of treatment pathways, our Expert Witnesses in Endocrinology can advise on causation, breach of duty, current condition, and prognosis in individuals with conditions affecting their endocrine system.
See below for a brief overview on endocrinology. Alternatively, contact an Expert Witness in endocrinology to see how they can help.
What is Endocrinology?
The endocrine system is comprised of a variety of glands and organs responsible for releasing hormones to regulate metabolism, reproduction, growth, mood, and development. The main features of the endocrine system include:
- Hypothalamus
- Pituitary gland
- Pineal gland
- Thyroid gland
- Parathyroid glands
- Thymus
- Pancreas
- Adrenal glands
- Gonads (ovaries, testicles)
Hypothalamus
The hypothalamus is located within the brain and is responsible for thermoregulation (regulating the body temperature), controlling appetite, and regulating the pituitary hormones. The secretion of hormones by the hypothalamus is pulsatile and is susceptible to influence from stress and infection. Hypothalamic dysfunction can lead to numerous conditions including:
- Cranial diabetes insipidus – insufficient production of anti-diuretic hormone (ADH) by the hypothalamus results in excess urination (polyuria) and increased thirst (polydipsia).
- Prader-Willi syndrome – a genetic condition whereby hypothalamic dysfunction leads to excess eating and a lack of satiety.
Pituitary Gland
The pituitary gland is located at the base of the brain inside the protective, bony, sella turcica. The pituitary is largely controlled by the hypothalamus and is responsible for the functioning of the majority of other endocrine tissues. The pituitary gland is divided into the anterior lobe and the posterior lobe, each of which have different functions.
The posterior pituitary gland secretes:
- Antidiuretic hormone (ADH) – acts on kidneys to decrease water excretion.
- Oxytocin – stimulates and maintains labour and induces lactation.
The anterior pituitary gland secretes numerous hormones in response to the hypothalamus. Hormones secreted by the anterior pituitary gland include:
- Prolactin – stimulates lactation.
- Adrenocorticotrophic hormone (ACTH) – stimulates the adrenal glands, producing mainly cortisol.
- Follicle stimulating hormone (FSH) – acts on the gonads.
- Luteinising hormone (LH) – acts on the gonads.
- Growth hormone – acts on bones, muscles, and fat tissue.
- Thyroid stimulating hormone (TSH) – stimulates the thyroid gland.
- Melanocyte stimulating hormone – stimulates melanocytes in the skin.
A pituitary tumour can lead to the under or over production of hormones. A specific example of this is a prolactinoma; a tumour of the pituitary gland which produces excess prolactin leading to galactorrhoea, amenorrhoea, erectile dysfunction, and male hypogonadism.
Pineal Gland
The pineal gland is a small gland in the brain which produces melatonin, a hormone responsible for regulating sleep.
Thyroid Gland
The thyroid gland is an organ in the front of the neck which produces the thyroid hormones known as T3 and T4 (thyroxine) in response to thyroid stimulating hormone.. Thyroid hormones control metabolism and affect the body’s basal metabolic rate, fat production, temperature, mood, protein synthesis, and glucose metabolism. Whilst a normal thyroid cannot usually be palpated, an enlarged thyroid is referred to as a goitre and presents as a swelling in the neck.
Dysfunction of the thyroid gland leads to hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid), both of which have widely systemic effects on the body.
In hypothyroidism, the impacts can be thought of as having a “dampening” affect i.e., low mood (depression), fatigue, slow heart rate (bradycardia), reduced metabolic rate (weight gain), reduced bowel activity (constipation), and cold intolerance.
In hyperthyroidism, the impacts can be considered to have a heighted affect i.e. anxiety, restlessness/mania, increased heart rate (tachycardia), increased metabolic rate (weight loss), increased bowel activity (diarrhoea), and heat intolerance.
Parathyroid Glands
The parathyroid glands sit on each lobe of the thyroid gland and secrete parathyroid hormone to increase calcium levels in the body through three different methods:
- Increase bone resorption i.e. breakdown of bone, releasing calcium.
- Increase calcium reabsorption in the kidneys.
- Increase production of vitamin D leading to increased absorption of calcium from the gut.
Hyperparathyroidism leads to excess secretion of parathyroid hormone and raised serum calcium levels (hypercalcaemia), osteoporosis, and hypertension. Hypoparathyroidism leads to reduced secretion of parathyroid hormone and reduced calcium levels (hypocalcaemia), resulting in individuals requiring calcium therapy.
Thymus
The thymus gland sits between the lungs in the chest. It is responsible for the production of white blood cells. The thymus produces the hormone thymosin which stimulates the development of specific white blood cells, known as T cells. Unlike most other endocrine tissue, the thymus is most active during infancy and childhood, becoming largely inactive past puberty.
Pancreas
Information on the endocrine function of the pancreas can be read here.
Adrenal Glands
Located on top of both kidneys lie the adrenal glands. The centre (medulla) of each adrenal gland secretes adrenaline and noradrenaline. A pheochromocytoma is a tumour of the adrenal medulla which results in increased secretion of adrenaline and constant activation of the “fight or flight response”.
The outer cortex of the adrenal glands secretes:
- Cortisol – a steroid with a wide variety of affects on the body.
- Aldosterone – controls the balance of sodium and potassium and is a major player in the renin-angiotensin-aldosterone system (RAAS) which regulates blood pressure.
- Androgen precursors – converted to testosterone and oestrogen in the gonads.