Endocrine glands Flashcards
Anterior pituitary gland/adenohypophysis- location and hormones produced (7 things)
- Base of brain
- TSH
- ACTH
- FSH
- LH
- GH
- Prolactin
Posterior pituitary gland/neurohypophysis- location and hormones secreted (3 things)
- Base of brain
- ADH/vasopressin
- Oxytocin
Thyroid gland (3 things)
- Anterior to trachea
- Thyroxine (T4)
- Triiodothyronine (T3)
Parathyroid gland (3 things)
- Dorsal surface of thyroid gland
- 4 glands, 2 pairs
- Parathormone (PTH)
Adrenal glands (3 things)
- Top of each kidney
- Cortex secretes corticosteroids
- Small amounts of androgens, oestrogen & progestin
Pancreas (3 things)
- Left of and behind stomach
- Digestive enzymes into duodenum
- Insulin and glucagon
Glycoproteins and peptide hormones (5 things)
- Made in advance
- Dissolved in plasma
- Receptor on cell membrane
- 2nd messenger systems; may activate gene expression
- Insulin, glucagon, prolactin, ACTH, PTH, gastrin
Steroid hormones (5 things)
- Synthesised on demand
- Bound to carrier proteins in blood
- Receptors in cytoplasm or nucleus
- Transcription & translation factors
- Oestrogens, androgens, progesterone, cortisol, glucocorticoids
Catecholamines (5 things)
- Made in advance
- Dissolved in plasma
- Receptors on cell membrane
- 2nd messenger systems
- Adrenaline, noradrenaline, dopamine
Thyroid hormones (5 things)
- Made in advance
- Bound to carrier proteins in blood
- Receptors on nucleus
- Transcription & translation factors
- T4, T3
Lipid hormones (5 things)
- Synthesised on demand
- Dissolved in plasma and bound to carrier proteins
- Receptors on cell membrane
- 2nd messenger systems
- Thromboxanes, prostaglandins, endocannabinoids
What does the hypothalamus produce (2 things)?
- ADH and oxytocin that travel to posterior pituitary through nerves
- 6 hormones that travel via hypothalamo-hypophyseal portal system to anterior pituitary
What are portal systems (2 things)?
- Blood passes through 2 sets of smaller vessels before returning to heart
- Collects in portal vessels (portal veins) before entering veins
Clinical consequences of autoantibodies in thyroid gland (2 things)
- Hyperthyroidism (low TSH, high T4 & T3)
- Hypothyroidism (high TSH, low T4 & T3)
Parafollicular cells (6 things)
- Neuroendocrine cells that migrate into thyroid during development
- Produce thyrocalcitonin
- Monitors plasma Ca concentrations and decreases Ca2+ levels
- Independent of thyroid hormone synthesis
- Major effect: inhibits osteoclast activity in bone
- Minor effect: inhibits renal Ca and P reabsorption in tubular cells
Function of parathyroid gland (4 things)
- Constantly monitor plasma Ca concentrations
- Make PTH when conc. low
- Bones release Ca, prevent loss by kidneys, absorb more from GI tract
- Classical negative feedback loop
Clinical consequences of parathyroid dysfunction (2 things)
- Hyper/hypoparathyroidism
- Affects digestive system, brain, muscles and bones
Adrenal medulla- what does it contain? (3 things)
- Contain chromaffin cells (modified neurones)
- Secrete catecholamine
- Act as post-synaptic neurones
Adrenal cortex (3 things)
- Zona glomerulosa: aldosterone
- Zona fasciculata: glucocorticoids
- Zona reticularis: androgen precursors
Stress response of adrenal glands (2 things)
- ACTH binds to receptors in adrenal cortex
- As chromaffin cells are equivalent of post-synaptic neurones, this is an example of neurocrine secretion
Pancreas key features (4 things)
- Acinar glands grouped into lobules
- Many zymogen granules
- Connected through many intercalated ducts to pancreatic duct
- Joins with bile duct to make common bile duct
Exocrine functions of pancreas (8 enzymes)
- Trypsinogen
- Chymotrypsinogen
- Lipase
- Amylase
- Ribonuclease
- Deoxyribonuclease
- Gelatinase
- Elastase
Endocrine functions of pancreas (9 hormones)
- Glucagon
- Insulin
- Somatostatin
- Pancreatic polypeptide
- Vasoactive intestinal peptide
- Secretin
- Motlin
- Substance P
- Ghrelin
- Gastrin
