T1 L4:Calcium Homeostasis Flashcards
what are the 3 layers of the adrenal gland
The Fasciculata
Glomerulosa
Reticularis
Medulla
what are the adrenal causes of hypertension
Primary Hyperaldosteronism/conns syndrome
Adenoma
Rare genetic causes )
Phaeochromocytoma
Congenital adrenal hyperplasia
what zone is primary hyperaldosteronism in
Zone glomerulosa
what are the main causes of Hyperaldosteronism
Adenoma
Hyperplasia
Rare genetic causes
what is Phaeo-
Tumour of the adrenal medulla -some forms of the congenital adrenal hyperplasia
what is Angiotensinogen made by
Liver
what converts angiotensinogen to angiotensin 1
Renin
what is renin released by
kidney
what coverts angiotensin 1 to 2 and made by what organ
ACE and by the lungs
what are the effects of angiotensin 2 on AT 2 receptor
Vasodilation
ADH seceretion
what are the effects of angiotensin 2 on AT 1 receptor
Vasoconstriction
sympathetic activation
what is another name for primary hyperaldosteronism-
Conns syndrome
what group of people do we screen for conn’s disease
- Hypokalaemia
- Resistant hypertension ( 3 drugs )
- Younger people
what is Primary hyperaldosteronism (PA)
Individuals with PA have more vascular and renal pathology than people with Essential Hypertension & similar Blood pressure
what are the initial screening tests for primary hyperaldosteronism
Supressed Renin
Normal / High Aldosterone
what is the confirmatory test for primary hyperaldosteronism
Oral or IV Na+ suppression test
what are the Primary HyperaldosteronismTests for specific Aetiologyi.e secreting Adenoma or bilateral Hyperplasia
Adrenal CT scan
Adrenal venous sampling
Is the aldo secretion unilateral?
Metomidate PET CT
how do you treat a Unilateral adenoma
Laparoscopic Adrenalectomy
Medical Treatment ( sometimes )
how do you treat a Bilateral Hyperplasia
Medical Treatment
Aldosterone Antagonists
Spironolactone
Eplerinone
what structures innervate the adrenal medulla and its blood supply
the preganglionic and postganglionic nerve fibres
what is the process of sympathetic stimulation of the adrenal medulla
Tyrosine- converts L-Dopa to dopamine which is released
Dopamine is converted to noradrenalin and noradrenalin is converted to adrenalin which is released
what are the 2 main products of the adrenal medulla
- dopamine
- Norepinephrine (Noradrenalin)
- (created via the above + cortisol)Epinephrine
what hormone causes the conversion of norepinephrine into epinephrine
Cortisol
what are the biological effects of catecholamine’s noradrenalin
Noradrenalin (alpha 1 & 2 ):
- vasoconstriction-increased BP,Pallor
- Glycogenolysis
what are the biological effects of catecholamine’s adrenalin
Adrenalin (Alpha 1, Beta 1 &2)
- vasoconstriction
- Vasodilation in the muscle
- increased heart rate
- sweating
what are the presentations (signs) of Phaeochromocytoma
“Spells”
Headache, Sweating
Pallor, Palpitation
Anxiety
Hypertension
Permanent
Intermittent
Family history
what is MEN
Multiple endocrine neoplasia
what is NF
Neurofibromatosis
what are the genetic conditions associated with Phaeochromocytoma
NF1
MEN 2
Von Hippel-Lindau
syndrome
what Biochemical tests can be used to diagnose Phaeo
24 hour urine
- 3 Methoxytyromine
Plasma - nor/adrenalin
Both- test for metanephrines
what are the other causes of high catecholamine levels
Obstructive Sleep Apnoea
Amphetamine like drugs
L-DOPA
Labetalol
can you measure dopamine in the urine for Phaeos
No as It comes from the kidney and NS
what can you measure instead of dopamine in the urine
urine Methoxytyramine
what can you use to mnage Phaeos
-Alpha blockers- Doxazocin & phenoxybenzamine
-Beta blockers
such as propranolol
-Laparoscopic adrenalectomy
