Introduction to Endocrinology
Dr. Haidar F. Al-RubayeEndocrinology concerns the synthesis, secretion and action of hormones. These are chemical messengers released from endocrine glands that coordinate the activities of many different cells. Endocrine diseases can therefore affect multiple organs and systems.
Some endocrine diseases are common, particularly those of the thyroid gland, reproductive system and β-cells of the pancreas
Other diseases are relatively rare
Clinical Assessment of Patients with suspected Endocrine Disorders
Clinical Assessment of Patients with suspected Endocrine DisordersHeight & weight
• Increased weight, hypothyroidism, Cushing's
• Weight loss, hyperthyroidism, adrenal insufficiency• Increased height, growth hormone overproduction
• Short stature, growth hormone deficiency, genetic disorders
Clinical Assessment of Patients with suspected Endocrine Disorders
Hands• Palmar erythema- Thyrotoxicosis
• Tremor- Thyrotoxicosis
• Acromegaly
• Carpal tunnel syndrome- hypothyroidism
Pigmentation of creases due to high ACTH levels in Addison’s disease
Acromegalic hands.Note soft tissue enlargement causing ‘spade-like’ changes
Clinical Assessment of Patients with suspected Endocrine Disorders
Skin• Hair distribution
• Dry/greasy
• Pigmentation/pallor
• Bruising
• Vitiligo
• Striae
• Thickness
Vitiligo in organ-specific
autoimmune disease
Clinical Assessment of Patients with suspected Endocrine Disorders
Pulse• Atrial fibrillation
• Sinus tachycardia
• Bradycardia
Blood pressure
Hypertension
in Cushing’s & Conn’s syndromes, phaeochromocytomaHypotension
in adrenal insufficiency
Clinical Assessment of Patients with suspected Endocrine Disorders
Clinical Assessment of Patients with suspected Endocrine Disorders
Clinical Assessment of Patients with suspected Endocrine Disorders
Functional anatomy and physiologySome endocrine glands, such as the parathyroids and pancreas, respond directly to metabolic signals, but most are controlled by hormones released from the pituitary gland.
Anterior pituitary hormone secretion is controlled in turn by substances produced in the hypothalamus and released into portal blood, which drains directly down the pituitary stalk
Posterior pituitary hormones are synthesised in the hypothalamus and transported down nerve axons, to be released from the posterior pituitary. Hormone release in the hypothalamus and pituitary is regulated by numerous stimuli and through feedback control by hormones produced by the target glands (thyroid, adrenal cortex and gonads).
The principal endocrine ‘axes’
The principal endocrine glands
Endocrine pathology
Endocrine pathology
Classification of endocrine diseaseInvestigation of endocrine disease
Biochemical investigations play a central role in endocrinology.Most hormones can be measured in blood, but the circumstances in which the sample is taken are often crucial, especially for hormones with:
Pulsatile secretion- such as growth hormone
Diurnal variation- such as cortisol
Monthly variation- such as oestrogen or progesterone.
Other investigations such as imaging and biopsy are usually reserved for patients who present with a tumour.
Principles of endocrine investigation
Principles of endocrine investigationPresenting problems in endocrine disease
Endocrine diseases present in many different ways and to clinicians in many different disciplines.Classical syndromes are described in relation to individual glands in the following Lectures.
Often, however, the presentation is with non-specific symptoms or with asymptomatic biochemical abnormalities
Examples of non-specific presentations of endocrine disease-1