HPA axis Flashcards
What is the HPA axis made up of
Hypothalamus
Pituitary gland
Adrenal gland
hormones produced in the hypothalamus
Corticotrophin releasing hormone (CRH) Dopamine Growth hormone-releasing hormone (GHRH) Growth hormone-inhibiting hormone (GHIH) Gonadotrophin-releasing hormone (GRH) Thyrotrophin-releasing hormone (TRH)
What are alternative neames for GHRH and GHIH
GHRH - somatostatin
GHIH - somatocrinin
What do the hormones released from the pituitary gland help control
Growth
Blood pressure
energy management
Some aspects of pregnancy,childbirth and breastfeeding
What are the anterior and posterior pituitary glands known as
Adenohypophysis
Neurohypophysis
Hormones secreted by adenohypophysis
Prolactin Thyroid-simulating Hormone (TSH) Adrenocorticotrophin (ACTH) Growth hormone (GH) (Somatotrophin) Follicle-stimulating hormone (FSH) Luteinising hormone (LSH)
What are trophic hormones
control the secretion of other hormones
What is the only pituitary gland hormone that acts on non-endocrine target
Prolactin
What acts as the hypothalmic release inhibiting hormone for prolactin and somatotropin
Prolactin - Dopanime
Somatotropin - somatostatin
What is the portal system delivery of hormones
Consists of two sets of capillaries connected in a series by small set of veins
Hypothalmic neurohormones enter the blood at the first set of capillaries and directly thorugh the portal veins to the second capillary bed in adenohypophysis
What 2 neurohormones are secreted and stored in the Posterior PG
Oxytocin
Vasopressin
What does vasopressin do
Acts on kidneys to regulate water balance
What does oxytocin do
Controls milk ekection during breast-feeding and uterine contraction in labour
What does ACTH action on adrenal cortex stimulate
Synthesis and release of cortisol
What are the roles of cortisol
Stress related factors Acting as anti-infammatory rehulating blood pressure Increasing blood sugar regulating salt and water balance
