Endocrine Glands Flashcards
What is the function of the endocrine system?
Maintaining homeostasis
What are some features of the endocrine system?
Network of glands
No ducts - secrete hormones directly into the bloodstream
Diffuse with endocrine organs in the cranium, neck, thorax, abdomen and pelvis
Found where there are major blood supplies
What do the endocrine organs do?
Secrete hormones to regulate bodily functions, including growth and metabolism
What does the pituitary gland secrete?
ACTH - adrenocorticotrophic hormone TSH - thyroid stimulating hormone LH - lutenising hormone FSH - follicle-stimulating hormone PRL - prolactin GH - growth hormone MSH - melanocyte stimulating hormone ADH - antidiuretic hormone oxytocin
What are some features of the pituitary gland?
Infundibulum
Hypothalamus
Anterior lobe (glandular tissue) (adenohypophysis)
Posterior lobe (neural tissue) (neurohypophysis)
What are ADH and oxytocin released by? Where do they then go?
ADH - supraoptic nuclei
Oxytocin - paraventricular nuclei
Both from posterior lobe
Axons transport oxytocin and ADH from nuclei -> hormones secreted directly into the capillary bed -> ADH acts on kidneys and oxytocin acts on reproductive system
What is secreted by the adrenal cortex?
Aldosterone
Cortisol
Androgens
What is secreted by the adrenal medulla?
Adrenaline
Noradrenaline
What is the adrenal medulla?
A specialised sympathetic ganglion with preganglionic sympathetic fibres synapsing and stimulating adrenaline release
What are the zones of the adrenal cortex and what do they secrete?
Zona reticularis -> androgens (testosterone precursor)
Zona fasciculata -> glucocorticoids (cortisol)
Zona glomerulosa -> mineralocorticoids (aldosterone)
Where are the adrenal glands located?
- between the superomedial aspects of the kidneys and crura of the diaphragm
- in perineal fat
- not always in direct contact with the kidneys
- develop in the abdomen not in the pelvis like the kidneys so separate
What is the shape of the adrenal glands?
Right - pyramidal shape, contacts liver and IVC
Left - crescent shape, contacts spleen, stomach and pancreas
What is the arterial blood supply to the adrenal glands?
- superior suprarenal arteries (from inferior phrenic)
- middle suprarenal artery (from abdominal aorta)
- inferior suprarenal (from renal artery)
What is the venous drainage of the adrenal glands?
Large suprarenal vein
(right side from IVC)
(left side from left renal vein)
At what level does the thymus gland lie?
C5-T1