Renal Physiology pt 3 (Final Exam) Flashcards
What stimulates the Vasopressin release system?
- ↑ Serum osmolarity
- Hypotension
What receptors sense osmolarity?
Where are these located?
- Osmoreceptors
- Hypothalamus
5/6 of ADH release is determined from this structure.
Where is this located?
- Supraoptic Nuclei
- Anterior near optic nerves.
1/6 of ADH release is determined from what structure?
Where is this located?
- Paraventricular Nuclei
- Posterior; close to 3rd ventricle.
What are the two lobes of the pituitary gland?
Which of the two secretes vasopressin?
What coordinates with osmoreceptors & baroreceptors to induce vasopressin release?
- Adenohypophysis (anterior) & Neurohypophysis (posterior)
- Neurohypophysis secretes vaso
- Supraoptic & Paraventricular Nuclei.
What would occur with a cell if placed in a hypotonic solution?
- Swelling of the cell
What would occur with a cell if placed in a hypertonic solution?
- Cellular Shrinkage
What areas of the nephron are affected by ADH?
- Everywhere except the Proximal Tubule.
What areas are more affected by ADH?
- Descending thin limb
- Medullary collecting duct
What would occur immediately after head injury in regards to ADH?
What would occur over a longer period in this same trauma scenario?
- Short term: ADH release = SIADH
- Long term: no ADH = DI
What is a pathology characterized by excessive ADH called?
What things can cause this condition?
SIADH:
- Short term head trauma
- NSAIDs & opioids
- Anti-depressants (with high dose)
- Lung Cancer (lots of junk made by this cancer)
What pathology is characterized by insufficient levels of ADH?
What things can cause this condition?
Diabetes Insipidus:
- Head Injury (Long-term)
- EtOH
- Nephrogenic DI
What mechanism causes DI with EtOH use?
- EtOH inhibits release of ADH at the pituitary through Ca⁺⁺ current reduction.
What is nephrogenic DI?
What is an example of this condition?
- Inability of kidney to respond to ADH.
- Lithium - super high doses = 20L UO/day
What is the treatment for Central DI?
What type of drug is this?
- Desmopressin (DDAVP) - V2 Receptor Agonist.
What would characterize Addison’s disease?
What electrolyte abnormalities would be seen?
- Low Aldosterone
- ↓ Na⁺ & ↑ K⁺
What would characterize Conn’s Syndrome?
What would cause this?
What electrolyte abnormalities would be seen?
- High Aldosterone
- Adrenal Tumor causing hyperactivity
- ↓ K⁺ & ↑ Na⁺
What areas of the nephron are permeable to Urea?
- Proximal Tubule
- Thin descending limb
- Thin ascending limb
- Medullary Collecting Duct with ADH.
What areas of the nephron have NaCl permeability?
- Proximal Tubule
- Thin descending limb
- Thin ascending limb
What areas of the nephron are permeable to water?
- Proximal Tubule
- Thin Descending Limb
What areas of the nephron become permeable to water with ADH?
- Distal Tubule
- Cortical & Medullary Collecting Ducts
What areas of the nephron utilize active NaCl Transport?
- Proximal Tubule
- Thick Ascending Limb
- Distal Tubule
- Cortical & Medullary Collecting Duct
Everywhere except the thin limbs
What prevents volatility in serum sodium levels?
- ADH/Vasopressin System
Increased ADH & Angiotensin II will cause ________ thirst.
increased
Decreased ADH & Angiotensin II will cause ______ thirst.
decreased
What makes us crave salt?
- Angiotensin II
What causes decreased sensation of thirst?
- ↓ Osmolarity
- ↑ Blood volume
- ↑ Blood pressure
- ↓ Ang II
- Gastric Distension
What causes an increased sensation of thirst?
- ↑ Osmolarity
- ↓ Blood Volume
- ↓ Blood pressure
- ↑ Ang II
- Mouth Dryness
What drugs (discussed in lecture) will decrease ADH?
- Alcohol
- Clonidine
- Haloperidol
What drugs, discussed in class, will increase ADH?
- Morphine
- Nicotine
- Cyclophosphamide
What two bodily conditions will increase ADH levels?
- Nausea
- Hypoxia
What occurs with potassium homeostasis in renal failure? Why?
- K⁺ homeostasis fails
- Aldosterone system fails due to low nephron count.
If a kidney is donated, how much can the other kidney compensate?
How long would it take to develop this compensatory capability?
- 50%
- 6-12 months
What is the pathophysiology of a left stenotic renal artery?
- Left kidney sees ↓ BP at nephrons due to the stenosis.
- Renin is released, Angiotensin II is formed.
- Angiotensin II affects healthy Right Kidney and BP increases.
What would the treatments of a stenotic renal artery be in order of least invasive to most invasive?
- ACE inhibitors or ARBS
- Stenting
- Nephrectomy
What demographics are affected by Na⁺-sensitive hypertension?
- African Americans
- Asian Americans
What organ is not working correctly in essential hypertension?
How much would salt intake affect someone with healthy kidneys?
- Kidneys
- None
What endogenous molecule can mimic mannitol?
- Glucose
What natriuretic can cause acid/base problems? Why is this?
What other condition can this drug treat?
- Acetazolamide; ↓ HCO₃⁻ reabsorption
- Glaucoma
What drug is generally more effective; ACE inhibitors or ARBs?
- ARBs
Potassium sparing diuretics generally interfere with what?
- Aldosterone
NO donors & calcium channel blockers (CCBs) primarily affect what? What does this result in?
- Afferent Arteriole; results in ↑PCAP = ↑ Filtration.
What is the most common thiazide diuretic?
What drug class & specific drug is this thiazide often combined with?
- Hydorchlorothiazide (HCTZ)
- Triamterene (K⁺-sparing)
β agonism will result in what (in regards to the kidneys)?
- Water conservation
Does increased urine output postoperatively always mean that you have healthy kidneys? Why or why not?
- No; increased urine output could be from efferent arteriole constriction, meaning that their is still low perfusion downstream of the EA.
What would characterize Renal Insufficiency?
- 50-20% of normal GFR
What would characterize Renal Failure?
- 20-5% of normal GFR
What would characterize End-Stage Renal Disease (ESRD) ?
If the patient had 2million nephrons originally, what is the most they could now have if diagnosed with this condition?
- <5% GFR
- 100,000 nephrons left (1/20 original nephrons left)
At about what age would we start to see loss of nephrons?
- 40 years old
Vasa Recta are dependent on what to remain open?
What drugs would then be detrimental to the medullary nephrons where these are found?
- Prostaglandins
- NSAIDs (via COX2 inhibition specifically)
What would occur with the serum creatinine if GFR were cut in half?
How about if we had a scenario of 75% nephron loss?
- Creatinine would double.
- GFR 1/4 of normal = 4x serum creatinine.
Regarding osmolarity, intracellular fluid volume, and extracellular fluid volume what would occur if isotonic (0.9%) NaCl were given?
- Osmolarity would stay the same
- ICF would stay the same
- ECF would exand
Regarding osmolarity, intracellular fluid volume, and extracellular fluid volume what would occur if hypertonic (3%) NaCl were given?
- Osmolarity for ICF & ECF would increase
- ICF volume would contract
- ECF volume would expand
Regarding osmolarity, intracellular fluid volume, and extracellular fluid volume what would occur if hypotonic (0.45%) NaCl were given?
- Osmolarity for ICF & ECF would decrease
- ICF volume would expand
- ECF volume would expand
What drugs can make the body less tolerant of blood loss?
Why is this?
- ACE inhibitors & ARBs
- RAA-System is inhibited and BP can’t be raised as easily.
How much is surface area increased by the brush border?
- 20x
Differentiate Type A and Type B intercalated cells?
- Type A get rid of H⁺
- Type B retain H⁺
Where are Intercalated cells located?
What types are there?
What are they responsive to?
- Late Distal Tubule, Cortical & Medullary Collecting Ducts.
- Type A & B Intercalated Cells
- ADH
