H20/NA Blance; Na/K+ Balance Flashcards
How does ANP affect ECF Volume and Osmolarity?
ANP stimulates decrease in ECF volume and osmolarity by increasing H2O/Na+ excretion
How do control of RAAS and ANP differ from ADH?
RAAS and ANP depend on changes in body volume while ADH release largely depends on plasma osmolarity
Differentiate Positive vs Negative Na Balance.
Positive Na Balance: ExcretionIntake
- DEC ECF volume
- DEC BP
What are characteristic of all Natriuretic peptides?
- similar Renal, vascular, and RAAS suppression effects
- Derive from prohormone
- Cause INC cGMP
- Short half life (3-20 min) by Vasopeptidases
- Internalizes via receptor-edited endocytosis
What secretes renin?
Granular cells of the JG apparatus
What is the major stimulator of renin secretion? What are three factors which increase release?
Decreased pressure in Afferent arterioles
- Low perfusion pressure n afferent arteriole
- Low tubular flow in macula densa
- Highs sympathetic activity
What are the functions of Angiotensin II?
- Release of Aldosterone
- Release of AHD
- Increase tension in systemic blood vessels
***Very Potent vasoconstrictor
What type of chemical is the Latin American Pit Viper venom?
Ace Inhibitor (Captopril)
What role does Ace play in the trachea, lungs and diaphragm. How would ACE inhibitors affect this?
ACE breaks down bradykinin
Increased Bradykinin —> Vasodilation and inflammation of airways
What are significant side effects of ACE Inhibitors?
- Coughing
- Angiodemeda
- Dysgeusia
What are the stimuli for Aldosterone?
Major:
- High plasma angiotensin II
- High plasma K+
Minor:
- Acidosis
- Hyponatremia
- ACTH
What are the physiological actions of Aldosterone?
- Na+ Reabsorption
- K+ Secretion
- H+ Secretion
What type of hormone is aldosterone? What type of receptor does is bind?
Steroid mineralcorticoid hormone
Cytoplasmic receptor
What is Conn’s Syndrome?
- Primary hyperaldosteronism
- Renin-Independent aldosterone overproduciton
- INC ECF volume
- Hypervolemia, hypertension, hypernatremia, Hypokalemia, and metabolic alkalosis
- May exhibit “Aldosterone escape” —> Polyuria and Reduced nHypertension
What are the different types of Hypernatremia?
Conns Syndrome: INC body Na+
Diabetes insipidus: Low Body water; Normal Na+
Heat stroke: Low Na and Lower H20
Describe Secondary hyperaldosteronism
- Renin-dependent
- ex. Renal artery stenosis
- Renovascular hypertension
What is Bartter’s Syndrome?
- Mutation in Na/K/2CL transporter
- Hypokalemia, Hypercalceuria, Polyura
*similar to symptoms of abuse of loop diuretics
What is the use of loop diuretics for?
- Decrease positive lumen charge
- DEC paracellular trans sport of Ca and Mg
Describe Addisons Disease
- Primary adrenal cortical hyposecretion
- Low aldosterone and cortisol
- Weight loss, dehydration
- Hypotension, hypovolemia, postural hypotension
- Abnormal cutaneous pigementation
- GI disturbance
- Hyper pigementation
What is Liddell syndrome?
- Pseudohypoaldosteronism
- Amiloride Sensitive NA channels are defective (Hyperactive) —> Hypokalemia
- Autosomal dominant
- Severe hypertension with Hypokalemia
What is normal K+ levels?
3.5 - 5.5 mEq/l
What promotes K+ secretion in the distal tubule and collecting duct?
- High dietary K+
- Aldosterone
- High filtrate flow rate
Which cells are dependent on the state of K+ balance, and which secrete or absorb K+?
Secretion: Principal cells in cortical collecting duct and outer medulla
Reabsorption: H/K ATPase in alpha-intercalated cells of inner medullary collecting ducts
What is the function of Thiazides diuretics?
Inhibit Na/Cl symporter in early distal tubule
