Introduction to Endocrinology and Disorders

Introduction to Endocrinology

• The course covers the structure and function of endocrine glands
• It also covers diagnosis and treatment of endocrine disorders

Endocrine Disorders

• Hypercalcemia of Malignancy
• Prolactinoma
• Osteoporosis
• SIADH
• Pheochromocytoma
• Restricted Growth
• Obesity
• MODY
• Congenital adrenal hyperplasia
• Gestational Diabetes
• Cushing's Syndrome
• Gigantism
• Hashimoto's Disease
• PCOS
• Turner's syndrome
• Brittle Bones
• Addison's disease
• Diabetes insipidus
• Adrenal Fatigue
• Thyroiditis
• Graves' Disease
• Sheehan's syndrome
• Delayed Puberty
• Conn's syndrome
• Type 2 Diabetes
• Type 1 Diabetes
• Infertility

Historical Evidence (Egyptians)

• Egyptians understood the role of gonads in fertility and contraception
• Removal of ovaries or testes was linked to preventing pregnancy
• Eunuchs served in Pharaoh's harem
• Detected diabetes (through excessive thirst)

Ancient Egyptian Ruler (Akhenaten)

• Carvings of patients with acromegaly, goitre, and achondroplasia

Discovery of the First Hormone (Secretin)

• Starling and Bayliss (1902) discovered secretin
• Interaction between duodenum and pancreas
• Defined hormone as transported by blood to exerted effect

Early Treatments

• Brown-Séquard (1889) injected himself with blood from testicular veins, semen and extracts of animals
• Reported increased strength, stamina, and concentration
• Considered the first endocrine replacement therapy

Hormone of the 20th Century (Insulin)

• Insulin was one of the first proteins to be crystallized
• 1955- First fully sequenced protein
• 1958- First chemically synthesized protein
• 1979- First human protein manufactured by biotechnology

Effect of Insulin

• A young girl with diabetes (weighing 45lbs) was treated with insulin extracted from slaughtered cattle

Asprosin (2013)

• Synthesized and released by white adipose tissue during fasting
• Plays a role in appetite, glucose metabolism, insulin resistance, and lipodystrophy
• Its loss can cause lipid-dystrophy

Layout of Endocrinology Teaching

• MD103: Introduction to Endocrinology, cell communication, hypothalamus-pituitary, growth control, calcium metabolism
• MD124: Metabolism control - pancreas, thyroid, glucocorticoids
• MD123: Fluid balance
• MD121: Blood pressure
• MD210: Reproduction

Types of Glands

• Different types of glands are discussed
• Exocrine and Endocrine glands

What is a Gland?

• Specialized secretory cells
• Secreted material is usually liquid
• Can be unicellular or multicellular (simple or complex)
• Classified as exocrine or endocrine

Exocrine Glands

• Secrete products onto epithelial surfaces, directly or through ducts
• Examples: Gastric glands, pancreas, salivary glands

Endocrine Glands

• Ductless glands
• Secrete hormones into the bloodstream
• Examples: Pituitary, thyroid, adrenal glands

One Organ More Than One Type of Gland (Pancreas)

• Pancreas has both exocrine (acinar cells) and endocrine (pancreatic islets) functions
• Also releases pancreatic hormones (insulin and glucagon)

Glands of the Body

• Various glands depicted, including pituitary, thyroid, thymus, adrenal, kidney, heart, digestive tract, gonads, etc.

What is a Hormone?

• Chemical substance produced by cells, carried in the bloodstream, acts on target cells at low concentrations
• Modern definition includes factors produced locally, and exert their effects

Hypothalamus and Pituitary

• Master gland
• Controls other endocrine glands
• Hypothalamic-pituitary axis, acts as relay station

Pituitary Embryological Derivation

• Anterior pituitary develops from the roof of the mouth (Rathke's pouch)
• Posterior pituitary develops from the base of the brain

Neural Connection

• Cell bodies lie in the supraoptic and paraventricular nuclei of the hypothalamus
• Produce hormones (oxytocin, ADH) which are carried via axons
• Released at posterior pituitary

Hypothalamic-Anterior Pituitary Connection

• Hormones from the hypothalamus are released to portal system
• Stimulate/inhibit hormones released by the anterior pituitary

Hypothalamic-Anterior Pituitary: Vascular Connection

• Blood circulation details outlined in connection between hypothalamus and anterior pituitary
• Blood entry, via superior hypophysial artery, to primary capillary plexus in median eminence
• Blood exiting primary plexus via hypothalamo-hypophyseal portal system
• Second capillary plexus in pars distalis

Hormones and Their Targets

• Chart illustrates releasing hormones targeting distinct organs
• Gonadotropin-releasing hormone, growth hormone releasing hormone, etc. all target specific glands

Clinical Examples

• Cases of Cushing's disease, diabetes insipidus, and infertility are detailed, covering the deficient hormones.
• The hormones are identified and the regions from which they originate are detailed.

This quiz explores the structure and function of endocrine glands, as well as various endocrine disorders such as diabetes and hypercalcemia. It also touches on historical evidence from ancient Egypt related to endocrinology and fertility practices. Test your knowledge on both modern and historical perspectives in endocrinology.