Renal System Flashcards
Generated from Lectures 41-47
The kidneys represent approximately ____ of the total body ATP consumption.
1/6
The kidneys filter about _____ liters of plasma per day.
180 liters
The filtration rate of the kidneys is approximately __________ at a blood pressure of 70 mmHg.
125 ml/min
The ______________ of the male urethra is under voluntary control and has extensive cholinergic innervation.
primary sphincter
The male urethra is approximately ___ cm long.
20 cm
The female urethra is approximately ___ cm long.
4 cm
The ____________ center in the brain controls the process of urination.
pontine micturition
Pelvic floor muscles are arranged in ______ around the urethra, rectum, and vagina.
slings
The functional unit of the kidney is the _______.
nephron
The nephron is responsible for ________ and _________ processes in the kidney.
filtration, transport
The __________ is the site of filtration in the nephron
glomerulus
The _______ is responsible for transport processes in the nephron.
tubule
The ___________ osmotic concentration gradient ranges from 300 to 1400 mOsm/L.
medullary
The ____________ (RPF) is approximately 605 ml/min.
renal plasma flow
The filtration fraction is calculated by dividing the _____ by the _____.
GFR, RPF
To measure GFR, a substance must be __________(five things).
freely filtered, not reabsorbed, not secreted, not synthesized by the tubule, not broken down by the tubule
The mass of a solute equals the product of the solute concentration and the solvent ________.
volume
______ is a substance that can be used to measure GFR because it meets all five criteria for a substance used to measure GFR.
Inulin
__________ can be used to estimate GFR.
Creatinine
Creatinine overestimates GFR by approximately ____% because it is secreted by the tubules.
10%
The renal clearance of a substance is the _____________ from which that substance is completely cleared by the kidneys per unit time.
volume of plasma
The normal renal clearance of glucose is _____ ml/min.
0 ml/min, because glucose is completely reabsorbed in the tubules.
The organic anion _______________ is secreted by the proximal tubule cells and can be used to measure effective renal plasma flow (ERPF).
para-aminohippurate (PAH)
Effective renal blood flow (ERBF) can be determined by dividing ______ by (____________).
ERPF, 1-hematocrit
___________ is the volume of blood plasma that is cleared of solute-free water per unit time.
Free water clearance
Free water clearance can be used as an indicator of how the body is regulating _______.
water
The glomerulus has three filtration barriers: _______, _______, and ________.
fenestrated endothelial cells, basal lamina, slit membranes
Fenestrated endothelial cells in the glomerulus are _______, allowing for a high filtration rate.
leaky
The basal lamina in the glomerulus acts as an initial sieve and is _________ charged.
negatively
Slit membranes in the glomerulus are located between ________ foot processes and act as sieves to restrict the passage of molecules larger than ___ nm in diameter.
podocyte, 5 nm
The _______________ is a specialized structure in the nephron that is involved in the regulation of GFR.
juxtaglomerular apparatus
The juxtaglomerular apparatus consists of __________ epithelial cells and ___________ cells.
macula densa, juxtaglomerular
________ is a mechanism that helps regulate GFR by sensing changes in fluid flow through the proximal tubule and loop of Henle.
Tubular glomerular feedback (TGF)
Factors that decrease TGF sensitivity include _________, ________, _________, and ________.
atrial natriuretic peptide, nitric oxide, cAMP, PGI2.
Factors that increase TGF sensitivity include ________, ________, ________, ________, and ________.
adenosine, thromboxane, 5-HETE, angiotensin II, prostaglandin E2
Renal autoregulation helps maintain a stable GFR despite changes in ___________.
blood pressure
Intrinsic control mechanisms of GFR include __________ response and ____________ feedback.
myogenic response, tubuloglomerular feedback
Extrinsic control mechanisms of GFR include __________, __________, and _________.
intrarenal baroreceptors, hormones, the sympathetic nervous system
___________ act as vasodilators in the kidney, increasing GFR.
Prostaglandins
__________ acts as a vasoconstrictor in the kidney, decreasing GFR.
Angiotensin II
__________ increases blood pressure and acts as a vasoconstrictor in the kidney, decreasing GFR.
Norepinephrine
____ acts as a vasodilator on the afferent arteriole and a vasoconstrictor on the efferent arteriole, increasing GFR.
ANP (atrial natriuretic peptide)
________(medication) cause afferent vasoconstriction, decreasing GFR.
NSAIDs
__________(medication) decrease efferent vasoconstriction, increasing GFR.
ACE inhibitors
The glomerular filtration rate (GFR) can be calculated using the formula: _________.
GFR = CI = (UI * V) / PI; where CI is the clearance of inulin, UI is the urine concentration of inulin, V is the urine flow rate, and PI is the plasma concentration of inulin.
The ______________ is the difference between the hydrostatic and oncotic pressures across the glomerular capillary wall, which drives filtration.
net filtration pressure (NFP)
The rate of filtration is determined by the product of the _________, ___________, and __________.
hydraulic permeability, surface area, net filtration pressure
The filtration coefficient (Kf) represents the mean filtration coefficient in _______________.
glomerular capillaries
The _________ capillaries reabsorb fluid and solutes from the renal tubules.
peritubular
The ____________ is responsible for the recovery of the filtered load and is the major site of solute secretion.
proximal tubule
The _____________ is responsible for ion reabsorption and some water reabsorption.
loop of Henle
Beyond the loop of Henle, the _________ segments are responsible for fine-tuning the final amounts of substances excreted.
nephron
True or False: The thick ascending limb of the loop of Henle is not water permeable.
True
The countercurrent multiplier system is responsible for producing and maintaining the medullary __________ concentration gradient.
osmotic
Organic nutrients that are reabsorbed in the _____________ include glucose, amino acids, acetate, Krebs cycle intermediates, water-soluble vitamins, lactate, acetoacetate, and b-hydroxybutyrate.
proximal tubule
Organic nutrient reabsorption in the proximal tubule occurs via ___________, usually coupled with sodium.
active transport
Organic nutrient transporters exhibit ___________, meaning that there is a maximum rate at which they can transport substances.
saturation
True or False: Organic nutrient transporters are specific, meaning that they only transport certain substances.
True
True or False: Organic nutrient reabsorption can be inhibited by drugs or disease states.
True
Approximately _____ g/day of protein is filtered, while normally only ______ mg/day is excreted.
1.8 g/day, 100 mg/day
Protein reabsorption occurs via _________ and is easily saturated.
endocytosis
Reabsorbed proteins are ___________ within the proximal tubule cells.
metabolized
Small proteins are reabsorbed via ___________.
endocytosis
Oligopeptides are reabsorbed via _______ or ________ coupled uptake.
sodium, proton
Glucose reabsorption in the proximal tubule occurs via _____________.
sodium-glucose cotransporters (SGLTs)
SGLT2 is located in the early proximal tubule and has a low ________ for glucose but a high capacity.
affinity
________ is located in the late proximal tubule and has a high affinity for glucose but a low capacity.
SGLT1
True or False: Glucose reabsorption is a passive process.
False
The transport maximum (Tm) for glucose is the _________ rate at which glucose can be reabsorbed.
maximum
______ refers to the appearance of glucose in the urine before the Tm is reached, due to variations in the affinity and capacity of SGLTs.
Splay
When plasma glucose concentration exceeds the Tm, glucose appears in the _____.
urine
Organic anions and cations are secreted into the ____________.
proximal tubule
Organic anion secretion is mediated by __________________.
organic anion transporters (OATs)
Organic cation secretion is mediated by ________________.
organic cation transporters (OCTs)
Organic anion and cation secretion is important for the ___________ of drugs, toxins, and metabolites.
elimination
The ____ of the tubular fluid can affect the excretion of weak acids and bases.
pH
___________ can reduce the clearance of memantine, leading to drug accumulation and potential adverse effects.
Alkaline urine
For a weak acid, the _______ form is more lipid-soluble and therefore more readily reabsorbed.
acidic
For a weak base, the _______ form is more lipid-soluble and therefore more readily reabsorbed.
basic
Water reabsorption is primarily driven by _______, following the movement of solutes.
osmosis
True or False: The water permeability of different nephron segments varies.
True
The proximal tubule is _______ water permeable.
highly
True or False: The thick ascending limb of the loop of Henle is water permeable.
False, it is not water permeable
The _____________ has variable water permeability, regulated by antidiuretic hormone (ADH).
collecting duct
The loop of ________ plays a crucial role in establishing the medullary osmotic concentration gradient.
Henle
The ____________ actively transports sodium, potassium, and chloride ions out of the tubular fluid, creating a hyperosmotic medullary interstitium.
thick ascending limb (TAL)
The _______ is impermeable to water, preventing water from following the reabsorbed solutes.
TAL
The ___________ limb is permeable to water, allowing water to move out of the tubular fluid into the hyperosmotic medullary interstitium.
descending
The ___________, a specialized capillary network surrounding the loop of Henle, acts as a countercurrent exchanger, maintaining the medullary osmotic gradient.
vasa recta
______ recycling also contributes to the medullary osmotic gradient.
Urea
True or False: Sodium reabsorption is a major function of the nephron.
True
In the proximal tubule, sodium is reabsorbed primarily via _______________, such as SGLTs and Na+/H+ exchangers.
sodium-coupled transporters
In the TAL, sodium is reabsorbed via the ________ transporter.
NKCC2
In the distal convoluted tubule and collecting duct, sodium reabsorption is regulated by ____________.
aldosterone
Sodium reabsorption occurs throughout the nephron, with approximately ____% reabsorbed in the proximal tubule, _____% in the loop of Henle, ____% in the distal tubule, and ____% in the collecting duct.
67%, 25%, 5%, 3%
The primary monitored variable for tubular regulation of sodium is ____________.
blood pressure
__________ is a hormone that plays a key role in regulating sodium reabsorption in the distal tubule and collecting duct.
Aldosterone
__________ is a hormone that stimulates aldosterone secretion and also has direct effects on sodium reabsorption.
Angiotensin II
___________ is a hormone that opposes the actions of aldosterone and angiotensin II, promoting sodium excretion.
Atrial natriuretic peptide (ANP)
The ___________________ is a hormonal cascade that is activated in response to decreased blood pressure or decreased sodium delivery to the distal tubule.
renin-angiotensin-aldosterone system (RAAS)
_______ is an enzyme that is released from the juxtaglomerular cells of the kidney in response to various stimuli, including decreased blood pressure, decreased sodium delivery to the distal tubule, and sympathetic nervous system activation.
Renin
Renin converts _________ to _________.
angiotensinogen, angiotensin I
Angiotensin I is then converted to angiotensin II by __________________, which is primarily found in the lungs.
angiotensin-converting enzyme (ACE)
The ______________ transporter is located in the thick ascending limb of the loop of Henle and is responsible for reabsorbing approximately 25% of the filtered sodium load.
sodium-potassium-chloride cotransporter (NKCC2)
_________, such as furosemide, inhibit NKCC2, leading to increased sodium excretion.
Loop diuretics
The ___________ channel is located in the distal tubule and collecting duct and is responsible for reabsorbing approximately 3% of the filtered sodium load.
epithelial sodium channel (ENaC)
_________ is a potassium-sparing diuretic that inhibits ENaC.
Amiloride
The _______________ (NCC) is located in the distal convoluted tubule and is responsible for reabsorbing approximately 5% of the filtered sodium load.
sodium-chloride cotransporter
The ___________ located in the carotid sinuses, aortic arch, and cardiac atria sense changes in blood pressure.
baroreceptors
AVP stands for ____________; it’s another name for anti-diuretic hormone (ADH).
arginine vasopressin
When blood pressure decreases, the baroreceptors signal the ______________ to increase heart rate and constrict blood vessels, which helps to increase blood pressure.
sympathetic nervous system
The sympathetic nervous system also stimulates _______ release from the juxtaglomerular cells of the kidney.
renin
Angiotensin II constricts __________ arterioles more than __________ arterioles, which helps to maintain glomerular filtration rate (GFR) despite a decrease in renal blood flow.
efferent, afferent
Angiotensin II also stimulates _______, which leads to increased water intake and helps to restore fluid volume.
thirst
_________ increases sodium reabsorption in the distal tubule and collecting duct by stimulating the expression and activity of ENaC and sodium-potassium ATPase.
Aldosterone
Aldosterone also promotes _________ excretion.
potassium
_____ is released from the atria of the heart in response to increased blood volume or atrial stretch.
ANP
ANP inhibits _______ reabsorption in the proximal tubule, loop of Henle, and collecting duct, leading to increased ________ excretion.
sodium, sodium
ANP also inhibits ______ and aldosterone secretion, further promoting sodium excretion.
renin
ANP increases GFR by ___________(dilating/constricting) afferent arterioles and ___________(dilating/constricting) efferent arterioles.
dilating, constricting
ANP decreases ___________ nervous system activity.
sympathetic
__________ are a class of drugs that increase urine output and are commonly used to treat hypertension.
Diuretics
__________ block the conversion of angiotensin I to angiotensin II, reducing the effects of angiotensin II on blood pressure and sodium reabsorption.
ACE inhibitors
_______________ block the binding of angiotensin II to its receptors, preventing its effects.
Angiotensin receptor blockers (ARBs)
_____________ block the effects of aldosterone on sodium reabsorption.
Aldosterone antagonists
__________ is a condition characterized by adrenal insufficiency, leading to a deficiency in aldosterone and cortisol.
Addison’s disease
Patients with ____________ may experience hypotension, hyponatremia, and hyperkalemia.
Addison’s disease
__________, also known as primary aldosteronism, is a condition characterized by excessive aldosterone secretion, leading to hypertension, hypokalemia, and metabolic alkalosis.
Conn’s syndrome
The kidneys are the major source of ____________, a hormone that stimulates red blood cell production in the bone marrow.
erythropoietin
Erythropoietin secretion is stimulated by __________ in the kidneys.
hypoxia
_________ can be caused by chronic kidney disease due to impaired erythropoietin production.
Anemia
Erythropoietin is a ________ hormone.
peptide
Renal interstitial cells are the major source of erythropoietin, with small amounts produced by the _______.
liver
The _____________________ is the pressure exerted by the fluid in the renal interstitium.
renal interstitial hydraulic pressure (RIHP)
An _________(increase/decrease) in RIHP opposes fluid reabsorption from the tubules.
increase
The ________________ pressure is the osmotic pressure exerted by the proteins in the peritubular capillaries.
peritubular capillary oncotic pressure
An increase in peritubular capillary oncotic pressure promotes ________ reabsorption into the capillaries.
fluid
The ________________ is the portion of the extracellular fluid volume that is effectively perfusing the tissues.
effective arterial blood volume (EABV)
A decrease in EABV activates the _______, leading to sodium and water retention to restore fluid volume.
RAAS
__________________ is an enzyme that converts cortisol to inactive cortisone in the kidney, preventing cortisol from binding to mineralocorticoid receptors and causing excessive sodium retention.
11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2
__________ contains glycyrrhetinic acid, which inhibits 11β-HSD2, potentially leading to sodium retention and hypertension.
Liquorice
___________ is a rare genetic disorder caused by a deficiency in 11β-HSD2, leading to sodium retention, hypertension, and hypokalemia.
Apparent mineralocorticoid excess (AME)
ADH is secreted by the __________________ and is also known as vasopressin (a vasoconstrictor).
posterior pituitary
_________(Increased/Decreased) pressure leads to decreased ADH, while __________(increased/decreased) pressure leads to increased ADH.
Increased, decreased
ANP acts as an ____________ in the system.
emergency brake
Salt sensitive hypertension can lead to ______ blood pressure.
high
True or False: The absence of aldosterone is always fatal.
True
Arginine vasopressin is human while lysine vasopressin is from ______.
pigs
Hypothalamic osmoreceptors (most likely sensitive to Na+ concentration) lead to _________(increased/decreased) ADH when osmolarity is increased and __________(increased/decreased) ADH when osmolarity is decreased.
increased, decreased
Osmoreceptor regulation of ADH is ______(more/less) sensitive than baroreceptor regulation of ADH.
more
V1 receptors are _______ GPCRs.
G alpha q
V2 receptors are ________ GPCRs.
G alpha s
__________ inhibits ADH secretion.
Alcohol
ADH is synthesized in the ___________ and released from the posterior pituitary.
hypothalamus
The target of ADH is the _______________, where it increases water reabsorption.
collecting duct
The ______________ (NTS) receives input from baroreceptors.
nucleus tractus solitarius
The _____ and _______ are involved in the osmoreceptor pathway.
OVLT, SFO
ADH increases _______ transport in the inner medullary collecting duct (IMCD).
urea
Increased urea reabsorption contributes to increased ___________________.
medullary interstitial osmolarity
___________ is the most important factor controlling thirst.
Plasma osmolarity
_____________ is the most common electrolyte abnormality found in hospital inpatients.
Hyponatremia
There are two types of diabetes insipidus: central DI and __________ DI.
nephrogenic
Central DI is a problem with ADH ________, while nephrogenic DI is a problem with the kidney __________ ADH.
release, perceiving
__________ alterations can be caused by excessive IV fluid administration, over-secretion of aldosterone, hemorrhage, severe wound drainage, and excessive sweating.
Isosmotic
_______________ can lead to weight loss, skin dryness, mucous membrane dryness, decreased urine output, rapid heart rate, and possibly low blood pressure.
Isosmotic volume depletion
_______________ can lead to weight gain, decreased hematocrit, increased blood pressure, edema, pulmonary edema, and heart failure.
Isosmotic volume excess
__________ is characterized by dysfunctional ADH, leading to an inability to concentrate urine and water diuresis.
Diabetes insipidus
_________ is a problem with ADH release from the posterior pituitary and can be acquired or congenital.
Central DI
___________ is a problem with the kidney perceiving ADH and is usually acquired.
Nephrogenic DI
Potassium is distributed with approximately ____% in the ECF and ____% in the ICF.
2%, 98%
__________ in the DCT and CD are responsible for potassium secretion, while _______________ are responsible for potassium reabsorption.
Principle cells, type A intercalated cells
Aldosterone directly stimulates potassium secretion by enhancing __________ activity.
Na/K-ATPase
_________(Increased/Decreased)potassium intake leads to increased potassium excretion.
Increased
Aldosterone plays a key role in potassium homeostasis by promoting potassium __________ in the DCT and CD.
secretion
Increased ________ flow rate enhances potassium secretion.
tubule
A high sodium diet leads to increased ___________ secretion, which in turn increases potassium secretion.
aldosterone
Hypokalemia is defined as serum potassium concentration less than _________.
3.5 mEq/L
__________ is defined as serum potassium concentration greater than 5.5 mEq/L.
Hyperkalemia
___________ can lead to increased neuromuscular excitability and cardiac dysrhythmias.
Hyperkalemia
Potential causes of ____________ include respiratory or metabolic alkalosis, insulin, dietary deficiency, diarrhea, vomiting, loop diuretics, and some antibiotics.
hypokalemia
Effects of _____________ include depressed insulin secretion, decreased concentrating ability, and decreased neuromuscular excitability leading to weakness and cardiac dysrhythmias.
hypokalemia
Potential causes of _____________ include respiratory or metabolic acidosis, insulin deficiency, increased intake, massive cell injury, hypoxia, and decreased renal secretion.
hyperkalemia
_______diuretics can lead to hypokalemia.
Loop
Diabetes insipidus is characterized by a ______ diuresis, while diabetes mellitus is characterized by an ________ diuresis.
water, osmotic
True or False: There is a such thing as an addiction to water.
True, known as psychogenic polydipsia
In diabetes mellitus, glucose builds up in the blood due to dysfunction of ________.
insulin
The increased filtered glucose in diabetes mellitus can ________ the transport maximum (Tm) of glucose transporters in the proximal tubule.
saturate
Glucose that is not reabsorbed in diabetes mellitus acts as an _______ in the collecting duct, preventing water reabsorption.
osmolyte
The amount of _______ in the extracellular fluid is the major determinant of extracellular volume.
sodium
Renal regulation of total-body sodium also achieves regulation of ____________.
extracellular volume
Potassium secretion is regulated by regulating ______ and potassium channels.
ENaCC
True or False: BK is only used when a lot of potassium secretion is required.
True
True or False: Increases in extracellular potassium increase aldosterone release.
True
99% of total body calcium is stored in bone as __________.
hydroxyapatite
The active, ionized form of calcium in plasma makes up about ______% of total plasma calcium.
45%
Around 40% of plasma calcium is buffered by _____________.
plasma proteins
Increased pH leads to __________ calcium binding to plasma proteins.
increased
Roughly 15% of plasma calcium is complexed with anions such as __________ and ___________.
citrate, phosphate
The major site for homeostatic control of calcium balance is the ________, where absorption is normally low.
GI tract
Approximately ______% of plasma calcium is filtered by the kidneys.
60%
___________ hormone increases serum calcium and decreases serum phosphate.
Parathyroid (PTH)
___________ (calcitriol) increases both serum calcium and serum phosphate.
Vitamin D3
_____________ decreases serum calcium but is only vestigial in humans.
Calcitonin
Longitudinal bone growth occurs at the ___________.
growth plates
Factors influencing longitudinal bone growth include:
local factors, growth hormone (GH), insulin-like growth factor (IGF-1), thyroid hormone, sex hormones
_____________ occurs when estrogen stimulates receptors in the growth plates, converting cartilage into bone and terminating longitudinal growth.
Epiphyseal closure
Why do long bones have spongey bone?
For strength-to-weight ratio (think cardboard)
___________ build bone, while ___________ resorb bone.
Osteoblasts, osteoclasts
What triggers epiphyseal plate closure?
Estrogen release during puberty (both males and females)
Roughly ____% of calcium reabsorption occurs in the proximal tubule, and around ____% occurs in the thick ascending limb of the loop of Henle.
50%, 80%
Chronic hypercalcemia can lead to _________________ ability in the kidneys.
reduced concentrating ability
What is osteoid?
Nonmineralized organic matrix in bone tissue
What is the signal for adaptive remodeling of bone?
Bone fluid flow (encouraged by exercise)
Approximately ______% of phosphate is filtered by the kidneys.
90-95%
____ inhibits phosphate reabsorption in the proximal tubule.
PTH
_____ stimulates both calcium and phosphate absorption in the intestine.
1,25-D3
Parathyroid hormone secretion is stimulated by _____(high/low) plasma calcium and high phosphate levels.
low
PTH secretion is inhibited by _____(low/high) plasma calcium and severe ____________.
high, hypermagnesemia
______ acts as the distributive control of calcium.
Bone
_________ is required for PTH secretion.
Magnesium
PTH stimulates bone __________ and calcium __________ in the kidneys.
resorption, reabsorption
PTH, ________, and thyroid hormones stimulate bone resorption.
cortisol
RANKL, also known as OPG ligand, is essential for ___________ differentiation.
osteoclast
RANKL stands for ________.
Receptor Activator of Nuclear factor-kB Ligand
__________ inhibits osteoclast differentiation.
OPG
Osteoclasts resorb bone by secreting _____ to dissolve the mineral component and _______ to degrade the organic matrix.
acid, enzymes
_________ diuretics act on the distal convoluted tubule to inhibit calcium reabsorption.
Thiazide
___________ is a hormone that decreases phosphate reabsorption in the kidneys.
FGF23 (fibroblast growth factor 23)
___________ deficiency can contribute to increased bone resorption and osteoporosis.
Estrogen
_________ is important for muscle contraction, nerve function, and blood clotting.
Calcium
__________ is an important component of DNA, RNA, and ATP.
Phosphate
__________ can cause symptoms such as fatigue, constipation, and kidney stones.
Hypercalcemia
______ are the regulators of active vitamin D3 by adding a hydroxyl group.
Kidneys
__________ can cause symptoms such as muscle cramps, tingling sensations, and seizures.
Hypocalcemia
True or False: Calcium is the most abundant mineral in the body.
True
__________ deficiency can lead to rickets in children and osteomalacia in adults.
Vitamin D
True or False: High levels of phosphate can stimulate bone resorption.
True
True or False: Calcitonin levels do not matter in a healthy individual.
True, vestigial; may be used as a therapy in people with osteoporosis
Calcium release in parathyroid cells _______ vesicular fusion, unlike in most other cell types.
inhibits
________ triggers vesicular fusion in parathyroid cells.
Magnesium
__________ increase the degradation of parathyroid hormone.
Leukotrienes
Acidemia is defined as a blood pH below _____.
7.37
Alkalemia is defined as a blood pH above _____.
7.42
Parathyroid hormone _______ phosphate reabsorption.
inhibits
Arterial blood pH values below 6.8 or above 8.0 are considered _______.
lethal
The major source of H+ gain is ______, with a production rate of 15-20 moles/day.
CO2
Although a large amount of CO2 is produced daily, it does not normally result in a net gain of H+ because _______________.
it’s exhaled by the lungs
Diarrhea can lead to a loss of HCO3-, resulting in a __________ in blood pH .
decrease
Vomiting can lead to a loss of H+, resulting in an ________ in blood pH.
increase
____________ leads to a decrease in PCO2 and an increase in blood pH.
Hyperventilation
Pulmonary insufficiency can lead to _______ retention, leading to a decrease in blood pH.
CO2
________ help to minimize changes in H+ concentration and pH.
Buffers
True or False: Buffering does not eliminate H+ from the body; that is the role of the kidneys.
True
Major extracellular buffers include: ___________
CO2-HCO3- system, phosphates, and proteins (such as hemoglobin)
Intracellular buffering accounts for ____-____% of the body’s buffering capacity.
50-90%
The amount of HCO3- filtered by the kidneys each day is approximately ______ mmol.
4320 mmol (about 4 moles)
New HCO3- is generated in the proximal tubule by ________ and __________.
glutamine uptake, NH4+ secretion.
_______________cells in the distal convoluted tubule and collecting duct are responsible for reabsorbing HCO3-.
Type A intercalated
H+ secretion in the distal nephron contributes to the formation of _________.
titratable acids
NH3 is produced from __________________ in the proximal tubule.
glutamine metabolism
The pKa of the NH3/NH4+ buffer system is _____.
9.2
The normal arterial plasma concentration of NH4+ is approximately _____.
40 nM
The pKa of the HPO42-/H2PO4- buffer system is _____.
6.8
Approximately ____ mmol/day of phosphate is available for H+ buffering in the urine.
36 mmol/day
_________ metabolism usually bears most of the compensatory burden in acid-base regulation.
Glutamine
Normal bicarbonate concentration in the plasma is ____.
24
_______________ is characterized by excessive CO2 loss (blowing off CO2).
Respiratory alkalosis
_________________ is characterized by CO2 retention.
Respiratory acidosis
_____________ is characterized by an increase in acid other than carbonic acid or a loss of HCO3-.
Metabolic acidosis
________________ is characterized by a loss of H+ or excessive intake of HCO3-.
Metabolic alkalosis
______ therapy can lead to metabolic alkalosis due to loss of K+, fluid volume contraction, and stimulation of aldosterone and angiotensin II.
Diuretic
Liver failure can cause hepatic ___________ in the brain, due to a rise in blood ammonium from liver metabolism dysfunction.
encephalopathy
