Hyperaldosteronism Flashcards
test results show: ↓ Renin ↑ Aldosteronism ↔ Cortisol What type of hyperaldosteronism is this
Secondary
What are the three ovarian cycle phases
- follicular- pre-ovulation
- follicular- late
- luteal
What causes secondary hyperaldosteronism
occurs as a result of anything causing decreased blood flow/pressure to kidneys or lowered blood Na conc
what are the 3 types of dehydration
hypotonic/hyponatremic - primarily loss of electrolytes
hypertonic/hypernatremic - primarily loss of water
isotonic/isonatremic - equal loss of water and electrolytes
What is osmolarity effected by
is affected by changes in water content, as well as temperature and pressure
What is dipstick testing
A urine test strip or dipstick test is a basic diagnostic tool used to determine pathological changes in a patient’s urine in standard urinalysis
What is the role of LH
binds to the ovaries causing the production of oestrogen, conversion of the Graafian follicle into the corpus luteum (produces progesterone
what is ANP
released from the atria
due to stretch/distension
binds to natriuetic peptide receptor resulting in guanylate cyclase activity - increase cAMP
smooth muscle relaxation, vasodilation of affertent
causes a decrease in renin and subsequently angiotensin and aldostrone
How do you control blood pressure short term
Neural- the mechanoreceptors in the carotid and aortic bodies detect changes which travel via either the parasympathetic/sympathetic NS
What happens in primary hyperaldosteronism
high aldosterone level increases reabsorption of sodium/water and loss of potassium by the kidneys
results high blood pressure/hypertension
muscle weakness can occur if potassium levels are very low
Is t3 or t4 more active
T4 is less active than T3 but is secreted in greater amounts from the thyroid
What is renal autoregulation
- the kidney itself can adjust the dilation or constriction of the afferent arterioles, which counteracts changes in blood pressure
what would indicate primary hyperaldosteronism in a sample
an increase in both renin and aldosterone
No change in cortisol
What is the osmolar gap
the difference between the measured osmolality and the calculated osmolarity
Give an example of a hormones produced in the Posterior PG
ADH /Vasopressin
Oxytocin
If a disease occurs at the pituitary axis, what type of disorder is it
Secondary
If cortisol doesn’t cause pseudohypoaldosteronism, what happens to it normally
11b-HSD2 converts it to cortisone
How do peptide hormones i.e. ADH or oxytocin cause vasoconstiction steps
Gaq –> PLC activated –> IP3 increased + DAG –> PKC –> phosphorylation of V1R = vasoconstriction
what is aldosterone
a hormone that regulates sodium and water retention by the kidney and the removal of potassium
important role in controlling blood pressure
What is a urine dipstick
A standard urine test strip may comprise up to 10 different chemical pads or reagents which react (change colour) when immersed in, and then removed from, a urine sample.
What are the effects t3 has on metabolism
o Increase glucose absorption o Increased glycogenolysis o Increased gluconeogenesis o Increased lipolysis o Increased protein catabolism
Give an example of a hormones produced in the hypothalamus
Thyrotropin RH
Corticotropin RH
Gonadotropin RH
What occurs in the PCT
reabsorption of o Glucose
o Amino Acids
o Other solutes such as phosphates and lactate
via sodium co transporters
What is a normal reference range of plasma osmolality
275-299 milli-osmoles / kg
what does angiotensin II stimulate
release of aldosterone
release of ADH
release of ANP
vasoconstriction
How does Hashimotos’ disease effect T3, T4 and TSH
Decreased T3 and T4, Increased TSH
what is plasma conc
conc of urine in blood after a IV injection
What two things are needed to breakdown cholesterol
ACTH and cholesterol desmolase
What are the main functions of the kidney
a regulator, excretor and producer
If fertilisation does not occur, what happens to the ovarian cycle
- Corpus luteum degenerates spontaneously
- Progesterone falls
- Uterus loses its endocrine support
- Menstruation
- FSH & LH get to work again on the follicles
What is the key function of the loop of henle
to maintain the osmotic gradient for water reabsorption
Give an example of a hormones produced in the adrenal cortex
aldosterone
what is the effect of ADH
released from the posterior pituitray increases fluid retention aquaporins in collecting duct V2R (Gs) stimulates aquaporins stimulates Na2+ K+ 2Cl- cotransporter
where is aldosterone produced
in the adrenal glands - located at the top of each kidney
What does T3 cause
DNA transcription
mRNA translation
Protein Synthesis
What will increased osmolality of the blood stimulate
secretion of ADH, resulting in: increases water reabsorption, more concentrated urine, and less concentrated blood plasma.
What may be tested using a urine disptick
Haematuria
Proteinuria
Glucose
UTI
how is the GFR regulated
intrinsic mechanisms
- renal autoregualtion - vasocontrsiction/dilation
extrinsic mechaisms
- neural/endocrine control - ANP = increase GFR
- tubulogolmular feedback - specialised cells within the distal tubule monitor Na2+
How does Graves’ disease effect T3, T4 and TSH
Increase T3 and T4, and decrease TSH
Explain the steps of the RAAS
- BP decreases, so kidneys release renin into the blood
- Renin converts angiotensinogen into angiotensin 1
- Angiotensin 1 is converted to angiotensin II by ACE
- Angiotensin II causes vasoconstriction, and the release of aldosterone by the adrenal glands
- Aldosterone causes sodium retention and potassium excretion
Give an example of a hormones produced in the thyroid
T3
T4
If fertilisation does occur, what happens to the ovarian cycle
- Corpus luteum maintained by hCG from the chorion
- Becomes the Corpus Luteum of Pregnancy
- Maintains uterine lining until placenta takes over as main producer of progesterone at 3 months
What is the initial hormone stimulating the menstrual cycle
Gonadotrophin Releasing Hormone (GnRH)
what is the glomerular filtration rate
rate of fluid filtered through the kidneys
estimates how much blood passes through the glomeruli each minute
Where does water move in, and solutes move out, in the nephron
Thin ascending limb
what is urine flow
amount of urine produced in a given time
What is the hypothalamus
The portion of the brain which maintains homeostasis and links the endocrine and nervous systems
Which cells in the kidney sense Na and CL in the tubular fluid
Macula densa cells
Describe the steps in pseudo-hyperaldosteronism
cholesterol –> progesterone –> cortisol –> increased sodium reabsorption and K and H excretion
What is osmolality affected by
is independent of temperature and pressure.
What is pseudo-hyperaldosteronism
Cortisol is not converted into cortisone by 11B-HSD2 and so binds to mineralocorticoid receptors in the renal cells, causing the same effects as aldosterone
What is the function of the thick ascending limb
actively reabsorbs sodium, potassium, and chloride. This is also impermeable to water
define hypoaldosteronism
lack of aldosterone
occurs as part of adrenal insufficiency
causes dehydration, low bp, low Na and high potassium blood concs.
What is the role of FSH
binds to the ovaries, stimulating the development of ovarian follicles, the secretion of oestrogen and the secretion of inhibin.
How do you calculate mean arterial pressure
Q X Total peripheral resistance
What are the two types of nephron
cortical and juxtamedullary
what would indicate secondary hyperaldosteronism in a sample
High levels of serum and urine aldosterone, along with a low plasma renin
No change in cortisol
What system controls long term BP
Renin-Angiotensin-Aldosterone System
test results show: ↓ Renin ↓ or ↔ Aldosteronism ↔ Cortisol What type of hyperaldosteronism is this
Pseudo
What is the role of progesterone
progesterone then causes the endometrium to become receptive to the implantation of the fertilised ovum.
Give an example of a hormones produced in the Adrenal Medulla
Adrenaline/Noradrenaline
Symptoms of Graves’ disease
Weight loss Goitre Ophthalmopathy Increased HR Sweating Tremor/anxiety
What is Graves’ disease
1* Hyperthyrodism- Autoimmune antibodies signal to make thyroid hormones
Where does water move out, and solutes move in, in the nephron
Thin descending limb
How can arterioles/veins help short term control of blood pressure regulation
cause vaso/venoconstriction to increase BP
What is Hashimoto’s disease
1* Hypothyroidism- Thyroid is destroyed, autoimmune thyroiditis
test results show: ↑ Renin ↑ Aldosteronism ↔ Cortisol What type of hyperaldosteronism is this
Primary
What are the effects t3 has on growth
o Bone maturation
o CNS maturation
If a disease occurs at the glands, what type of disorder is it
primary
Give an example of a hormones produced in the kidney
Renin
How is absorbed water returned to the circulatory system in the kidney
Via the vasa recta
What are the three major sections of the kidney
Cortex
Medulla
Renal Pelvis
What are the effects t3 has on the cardiovascular system
o Increase in Q
o Increased B-adrenoreceptors
o Increased Ca2+ ATPases
o Increased myosin
Give an example of a hormones produced in the Anterior PG
Thyroid Stimulating H Follicle Stimulating H Luteinising H Adrenal Cortico-Tropic H Growth H
How do steroid/thyroid hormones cause physiological actions
nuclear/cytoplasmic receptors bind DNA steroid receptor elements –> gene transcription –> mRNA –> new proteins
What element is needed for T3 and T4 production
Iodine
GFR equation
urine conc x urine flow/plasma conc
what is the effect of aldosterone
increase Na2+ and fluid retention (distal convoluted and collecting duct)
loss K+ and H+ in the urine
What are the 5 sections of a nephron
- Glomerulus
- PCT
- Loop of Henle
- DCT
- Collecting Duct
What are the effects t3 has on BMR
o Increased Na-K ATPase pump
o Increased oxygen consumption
o Heat production
o Increased BMR
What is the counter-current multiplier effect
uses energy to create an osmotic gradient enabling the reabsorption of water, and production of concentrated urine. It moves sodium chloride from the tubular fluid into the interstitial space deep within the kidneys
What receptors do angiotensin II use to cause vasoconstriction
AT1R
What receptors do both cortisol and aldosterone bind to
mineralocorticoid receptors
what causes primary hyperaldosteronism
caused by the overproduction of aldosterone in the adrenal glands
(usually by a benign tumour of one of the glands)
What are normal GFR rates for males and females
males - 125ml/min
females - 105ml/min
How is the kidney protected
encapsulated by a renal capsule, and further surrounded by adipose tissue
Symptoms of Hashimoto’s disease
weight gain. fatigue. paleness or puffiness of the face. joint and muscle pain. constipation. inability to get warm.
What is Neural (nervous system) control (GFR)
these extrinsic mechanisms can override renal autoregulation and decrease the glomerular filtration rate when necessary
where is renin produced
In the kidney (juxtaglomerular apparatus)