Anatomy & Physiology

Hypothalamus

Major homeostasis centre of the brain

Regulates body temperature, appetite, metabolic rate, sleep + many others

Link between brain and endocrine system via the pituitary gland - Hypothalamo-pituitary axis

Pituitary Gland

Major site of trophic hormone secretion – i.e. hormones that stimulate secretion of other hormones

Hormone secretion = controlled by hypothalamic hormones – who are inhibited by the presence of the final hormone in the chain – negative feedback

Divided into anterior and posterior pituitary

Most hormones are secreted by the anterior pituitary

Cells of the Anterior Pituitary

Classified by their specific secretory products:

Somatotrophs - GH secreting cells

Lactotrophs - PL secreting cells (prolactin)

Thyrotrophs  - TSH secreting cells (thyroid stimulating hormone)

Corticotrophs - ACTH secreting cells (adrenocorticotropic hormone)

Gonadotrophs - LH and FSH secreting cells (luteinising and follicle stimulating hormones)

Classification of endocrine disorders

Primary – the target gland itself (e.g. thyroid, adrenal, ovary) is not functioning normally

Secondary – initial disorder is in the pituitary and the problem in the target organ is secondary to the pituitary disorder

How a baby grows in the womb.