Dr. Rice Renal Final Flashcards
Transport maximum =
Tubular reabsorption
The limit to the rate at which a solute can be transported during active reabsorption or secretion is which type of tubular reabsorption?
Transport maximum
The type of tubular reabsorption that depends on the electrochemical gradient, permeability and time is called:
Gradient-time transport
True/False: Gradient-time transport can exhibit both passive and active elements.
True
What is osmosis?
The net diffusion of water across a selectively permeable membrane from a region of high water concentration to one of a lower water concentration
Osmosis involves the diffusion of water from _____ to _____ water concentrations.
High to low
What effects does capillary hydrostatic pressure have on arterial pressure?
As arterial pressure increases, GFR increases
Constriction of afferent arterioles leads to _____, while dilation of afferent arterioles leads to _____.
Decreased glomerular CHP and decreased GFR
Increased glomerular CHP and increased GFR
If the blood pressure arriving at the kidney was increased, what would happen to the amount of urine being produced?
Increased amount
Constriction of efferent arterioles would have what effects on glomerular CHP and GFR?
Increased glomerular CHP and increased GFR (slightly)
Which hormone causes increased water permeability?
ADH/Vasopressin
ADH causes increased water permeability where?
Distal tubule, collecting tubule and collecting duct
Osmoreceptor cells fire and stimulate the _____ to release ADH.
Posterior pituitary
What region is responsible for signaling the posterior pituitary to release ADH?
AV3V region
How much does sodium content increase when there is a desire to ingest fluid (thirst)?
Increases 2mEq/L above normal
GFR =
RPF x FF
Normal GFR is:
110 ml/min
How can GFR be increased?
Alter the RPF (increase cardiac output/dilate afferent arterioles) or alter the FF (contract efferent arterioles, increasing glomerular pressure)
How are glomerular capillaries different than others in the body?
They have 3 layers instead of 2 (endothelium, basement membrane and epithelial cell layer)
The filtration fraction is best defined as:
The proportion of the fluid reaching the kidneys which passes into the renal tubules
What separates glomerular and peritubular capillary beds?
Efferent arterioles
Which sodium glucose co-transporter transports the most filtered glucose?
SGLT-2 (90%, SGLT-1 is 10%)
Sodium reabsorption occurs where?
Proximal tubule
Which molecules are rapidly absorbed in the first half of the proximal tubule?
Sodium, glucose, amino acids and water
Which molecule is left in high concentrations in the second half of the proximal tubule?
Chloride ions
Kidney damage involves:
Impaired sodium excretion
What is the trade off that occurs when there is damage to the kidneys?
Increase blood pressure (helps maintain normal sodium excretion); harmful long-term though
What are principal cells?
Specialized epithelial cells in the late distal and collecting tubules that secrete potassium for excretion
What factors control potassium secretion by the principal cells?
Activity of Na/K ATPase pump, electrochemical gradient and K+ permeability
Which hormone stimulates active secretion of potassium via principal cells?
Aldosterone
A pH below 7.4 indicates:
Acidosis
A pH above 7.4 indicates:
Alkalosis
Describe the flow of urine.
Nephrons, collecting ducts, renal calyces, ureters and then the bladder
Sodium excretion in the urine describes pressure _____, while water excretion to regulate BP describes pressure _____.
Natriuresis; Diuresis
Hypokalemia is caused by excess _____ in the system.
Aldosterone (Conn’s syndrome)
Excess aldosterone in the system causes:
Hypokalemia
True/False: In a healthy adult, the glomerular filtrate should contain proteins and cellular elements.
FALSE; It shouldn’t contain ANY cellular elements
Which three things have an impact on extracellular fluid volume of H+ concentration?
Secretion of H+, reabsorption of filtered HCO3- and production of new HCO3-
The bladder is innervated by:
S2 and S3 nerves
The external anal sphincter is controlled by which nerve?
Pudendal nerve
The first line of defense against changes in H+ concentration.
Acid-base buffering system (seconds)
Reabsorption of sodium and secretion of potassium are both controlled by:
Aldosterone
The second line of defense against changes in H+ concentration.
Respiratory center (minutes)
The last line of defense against H+ concentration changes.
KIdney via acidic/basic urine (hours-days) –> most powerful mechanism
Renal blood flow accounts for what percentage of cardiac output?
22%
True/False: Kidneys consume more oxygen and blood than the brain.
True; 2x more oxygen, 7x more blood flow
How are glomerular and peritubular capillary beds different?
Glomerular- High hydrostatic pressure, rapid fluid filtration
Peritubular- Low hydrostatic pressure, rapid fluid reabsorption
Foamy urine is a sign of _____ in the urine, indicative of which disease?
Protein; Nephrotic syndrome
If osmolarities stay equal throughout the structure:
Isotonic
If osmolarities increase throughout the structure:
Hypertonic
If osmolarities decrease throughout the structure:
Hypotonic
Overhydration results when there is overly high secretion of:
ADH (over retention of water; hyponatremia) and aldosterone (excess NaCl; hypernatremia)
Intracellular edema is the result of:
Hyponatremia, metabolic depression and poor nutrition
Extracellular edema is the result of:
Fluid leakage and lymphatic failure (lymphedema)
When voluntary urination is desired, the micturition reflex is excited and the _____ signals for voluntary external urethral sphincter relaxation.
Pudendal nerve
The transport of sodium from the tubular cells into the interstitial fluid during reabsorption requires:
Potassium
A person who is sweating profusely is at risk for:
Hypernatremia
Someone with hyponatremia has very low levels of _____ in their blood.
Sodium
Juxtamedullary nephrons are distinct from cortical nephrons in that they have:
Significantly longer loops of Henle
If a patient is in a standing/upright position, where should the kidneys be located (approximately)?
Between L1-L4
Name the muscle responsible for contraction of the bladder.
Detrusor
A person experiencing flank pain and blood in their urine is likely going to be diagnosed with:
Polycystic kidney disease/Nephrolithiasis
This messed up kidney is showing signs of severe:
Polycystic kidney disease
Which of the following is a symptom of pyelonephritis?
Bilateral loin pain
Colloidal osmotic pressure in the glomerulus is proportional to the concentration of:
Proteins in the blood
Both norepinephrine and epinephrine have what effects on GFR?
Inhibitory
When arterial pressure is increased, some blood vessels have the ability to resist stretching. This is called:
Myogenic mechanism
Kidneys consume twice as much oxygen as the brain due to the high rate of _____ in the renal tubules.
Active sodium reabsorption
Angiotensin II is a powerful renal:
Vasoconstrictor
True/False: The renal cortex receives significantly less of the blood arriving at the kidneys than the renal medulla.
FALSE, the renal medulla receives less than the renal cortex
The kidneys can autoregulate, which means that even if arterial pressure varies greatly, there will be little net change in:
GFR
Glomerular filtration is _____, and tubular reabsorption is _____.
Non-selective; highly selective
Before a solute can be reabsorbed into the renal blood supply, it must first be:
Transported into the interstitial fluid
True/False: Secondary active transport is coupled directly to solute gradients.
FALSE, coupled INDIRECTLY
What is represented by the yellow colored portion of this diagram?
Filtrate
Where is energy (ATP) expended during glucose reabsorption in the kidneys?
By the Na/K ATPase transporters
The limit to the rate at which a solute can be transported during active reabsorption or secretion is called the:
Transport maximum
Osmosis causes a:
Solvent drag
Which segment of the Loop of Henle is impermeable to water? Which one is highly permeable to water?
Thick ascending segment is impermeable; Thin descending is highly permeable
The specialized principal cells of the kidneys are located in the:
Distal tubule
The presence of a high concentration of ADH in the cortical collecting tubule will make the membrane:
Permeable to water
Filtrate that has passed through the proximal tubule stays _____ relative to the blood plasma.
Isotonic
Which mechanism is driven by sodium movement in the proximal tubule and the thick ascending loop of Henle?
Countercurrent mechanism
True/False: The same urea may be secreted back into the nephron and recirculate multiple times.
True
One of the first systemic adjustments the body will make if the kidneys aren’t maintaining fluid balance is to:
Change blood pressure
