p.8
Fluid and Electrolyte Balance Concept
What is the primary function of the kidneys in fluid balance?
To conserve volume and recycle fluid.
p.7
Fluid and Electrolyte Balance Concept
What must be true to maintain a constant volume of water in the body?
Intake must equal output.
p.9
Mechanisms of Water Balance
What is the driving force for water reabsorption throughout the nephrons?
Osmotic gradient between the tubular lumen and surrounding interstitial fluid.
p.27
pH Homeostasis and Acid-Base Balance
What is the role of type B intercalated cells in the collecting duct during alkalosis?
They secrete HCO3- and reabsorb H+.
p.4
Fluid and Electrolyte Balance Concept
What are the four parameters that homeostatic control mechanisms aim to maintain?
Fluid volume, osmolarity, concentration of individual ions, and pH.
p.21
Integrated Control of Blood Volume and Osmolarity
How does the cardiovascular system contribute to fluid balance?
By regulating blood volume and pressure.
p.21
Fluid and Electrolyte Balance Concept
What is osmolarity?
The concentration of solutes in the blood.
p.7
Fluid and Electrolyte Balance Concept
What contributes to daily water gain besides drinking?
Food and metabolic production.
p.2
Mechanisms of Water Balance
What is the mechanism of water balance?
It involves the regulation of water intake and output to maintain homeostasis.
p.17
Kidney Functions in Fluid Regulation
What role does the kidneys play in response to salt ingestion?
The kidneys adjust sodium and water reabsorption to maintain balance.
p.6
Behavioral Mechanisms in Fluid Balance
What behavioral response is triggered by changes in blood pressure?
Thirst causes water intake.
p.25
pH Homeostasis and Acid-Base Balance
What is the role of H+ secretion in the proximal tubule?
It helps maintain pH homeostasis by combining with filtered HCO3- to form CO2.
p.16
Hormonal Regulation of Electrolytes
How does blood pressure influence vasopressin secretion?
Low blood pressure stimulates vasopressin release to increase blood volume.
p.1
Fluid and Electrolyte Balance Concept
What is the primary function of the urinary system?
To maintain fluid and electrolyte balance.
p.14
Medullary Vertical Osmotic Gradient
What is the vertical osmotic gradient?
A difference in osmolarity that allows for water reabsorption in the kidneys.
p.21
Hormonal Regulation of Electrolytes
What role does the renin-angiotensin system play in fluid balance?
It helps regulate blood volume and osmolarity.
p.2
pH Homeostasis and Acid-Base Balance
What is pH homeostasis?
It is the regulation of the acidity or alkalinity of body fluids to maintain a stable pH level.
p.26
pH Homeostasis and Acid-Base Balance
How does H+ secretion in type A intercalated cells differ from that in the proximal tubule?
It involves H+-K+-ATPase in type A intercalated cells.
p.22
pH Homeostasis and Acid-Base Balance
What is acidosis?
A condition where pH is too low.
p.20
Ion Balance and Homeostasis
What role does aldosterone play in potassium balance?
Aldosterone plays a critical role in potassium homeostasis.
p.2
Fluid and Electrolyte Balance Concept
What is the concept of balance in fluid and electrolyte regulation?
It refers to maintaining stable levels of fluids and electrolytes in the body.
p.6
Fluid and Electrolyte Balance Concept
What receptors are involved in detecting changes in blood volume and pressure?
Volume receptors in the atria, and carotid and aortic baroreceptors.
p.7
Fluid and Electrolyte Balance Concept
What is insensible water loss?
Water loss that occurs without conscious awareness, estimated at 0.9 L/day.
p.26
pH Homeostasis and Acid-Base Balance
How does HCO3- exit type A intercalated cells?
Through the HCO3--Cl- antiporter to the interstitial space.
p.3
Fluid and Electrolyte Balance Concept
What is the equation that represents fluid and electrolyte balance in the body?
Input + production = utilization + output.
p.10
Medullary Vertical Osmotic Gradient
What role does the medullary vertical osmotic gradient play in the kidneys?
It enables the kidneys to produce urine of varying concentration (100 - 1200 mOSm).
p.7
Fluid and Electrolyte Balance Concept
What are the avenues for water loss in the body?
Urine, lungs, feces, and skin.
p.20
Ion Balance and Homeostasis
How does aldosterone affect potassium ions?
It facilitates renal excretion of potassium ions.
p.2
Ion Balance and Homeostasis
What is the mechanism of ion balance?
It involves the regulation of ion concentrations in the body fluids to ensure proper physiological function.
p.3
Fluid and Electrolyte Balance Concept
What is the task of the body regarding electrolytes?
Maintain balance by excreting what comes in if the body does not need it.
p.10
Medullary Vertical Osmotic Gradient
How do collecting ducts utilize the vertical osmotic gradient?
They use it to concentrate urine.
p.4
Behavioral Mechanisms in Fluid Balance
What is salt appetite?
A behavior that leads people to seek and ingest salt (NaCl).
p.13
Countercurrent Multiplication and Urea Recycling
What is the pathway of the vasa recta?
It descends from the cortex to the medulla and loops back up to the cortex.
p.22
pH Homeostasis and Acid-Base Balance
What happens to intracellular proteins when there is a change in intracellular pH?
They can become denatured, affecting enzymes and membrane channels.
p.25
pH Homeostasis and Acid-Base Balance
What is the outcome of NH4+ secretion?
NH4+ is secreted and excreted, contributing to acid-base balance.
p.21
Fluid and Electrolyte Balance Concept
What is the primary focus of fluid and electrolyte balance?
The integrated control of blood volume and osmolarity.
p.17
Hormonal Regulation of Electrolytes
How does the body regulate sodium levels after salt ingestion?
Through hormonal mechanisms, including aldosterone secretion.
p.12
Medullary Vertical Osmotic Gradient
What two processes establish the medullary vertical osmotic gradient?
Countercurrent multiplication and urea recycling.
p.12
Fluid and Electrolyte Balance Concept
What is the permeability characteristic of the proximal cortical collecting duct?
It is permeable to water.
p.19
Hormonal Regulation of Electrolytes
What causes the release of Natriuretic peptides?
Increased blood volume leading to increased atrial stretch.
p.11
Countercurrent Multiplication and Urea Recycling
What is the characteristic of the ascending limb in countercurrent multiplication?
It is water impermeable and has active Na+ transport.
p.22
pH Homeostasis and Acid-Base Balance
What are the effects of acidosis on neurons?
Neurons become less excitable, leading to CNS depression.
p.24
pH Homeostasis and Acid-Base Balance
What role do buffers play in pH homeostasis?
They moderate changes in pH by combining with or releasing H+.
p.19
Ion Balance and Homeostasis
What is the relationship between renin and blood pressure?
Decreased renin leads to decreased blood pressure.
p.5
Ion Balance and Homeostasis
What functions are influenced by Ca2+?
Exocytosis, muscle contraction, and other cellular functions.
p.20
Behavioral Mechanisms in Fluid Balance
What stimulates salt appetite?
Low sodium levels stimulate salt appetite.
p.17
Fluid and Electrolyte Balance Concept
What is the primary homeostatic response to salt ingestion?
The body increases thirst and promotes water retention.
p.26
pH Homeostasis and Acid-Base Balance
What reaction does carbonic anhydrase (CA) facilitate in type A intercalated cells?
It converts CO2 and water to H+ and HCO3-.
p.10
Medullary Vertical Osmotic Gradient
What is the entire functional organization that involves the vertical osmotic gradient called?
Medullary countercurrent system.
p.8
Fluid and Electrolyte Balance Concept
Can the kidneys replace lost fluid volume?
No, they cannot replenish lost water.
p.8
Kidney Functions in Fluid Regulation
How is regulated water reabsorption related to urine volume?
It determines the volume loss in the urine.
p.13
Fluid and Electrolyte Balance Concept
What are the permeability characteristics of the vasa recta?
It is permeable to water and solutes.
p.13
Countercurrent Multiplication and Urea Recycling
What happens to solutes and water during the descent of the vasa recta?
Solutes are reabsorbed from the medullary interstitium and water is removed.
p.19
Hormonal Regulation of Electrolytes
What is the role of the adrenal cortex in fluid balance?
It releases aldosterone, which regulates sodium balance.
p.22
pH Homeostasis and Acid-Base Balance
What happens to neurons during alkalosis?
They become hyperexcitable, leading to sensory changes and sustained contractions.
p.20
Behavioral Mechanisms in Fluid Balance
What behavioral mechanism helps replace fluid loss?
Drinking replaces fluid loss.
p.26
pH Homeostasis and Acid-Base Balance
What role do type A intercalated cells play in the collecting duct during acidosis?
They secrete H+ and reabsorb HCO3-.
p.10
Medullary Vertical Osmotic Gradient
What is the function of the vasa recta in relation to the vertical osmotic gradient?
They preserve/maintain the vertical osmotic gradient while providing blood to the renal medulla.
p.6
Kidney Functions in Fluid Regulation
What role do the kidneys play in fluid balance?
They excrete salts and water in urine and conserve water to minimize further volume loss.
p.6
Integrated Control of Blood Volume and Osmolarity
How does the cardiovascular system respond to changes in blood pressure?
Through cardiac output and vasodilation or vasoconstriction.
p.16
Hormonal Regulation of Electrolytes
How does increased osmolarity affect vasopressin release?
It stimulates the release of vasopressin to conserve water.
p.16
Hormonal Regulation of Electrolytes
What role does blood volume play in vasopressin release?
Decreased blood volume triggers vasopressin release to retain water.
What happens to concentrated urea in the distal collecting duct?
It moves into the renal interstitium and can be recycled.
p.22
pH Homeostasis and Acid-Base Balance
What can result from severe CNS depression due to acidosis?
Cease of respiratory center function and death.
p.19
Fluid and Electrolyte Balance Concept
What substances are excreted due to increased blood volume?
NaCl (sodium chloride) and H2O (water).
p.24
pH Homeostasis and Acid-Base Balance
How does renal regulation manage pH disturbances?
By directly excreting or reabsorbing H+ and indirectly changing the excretion or reabsorption of HCO3-.
p.15
Kidney Functions in Fluid Regulation
What is the role of the collecting duct in urine concentration?
It allows variable reabsorption of water, influenced by hormones.
p.14
Kidney Functions in Fluid Regulation
What role do collecting ducts play in fluid and electrolyte balance?
They utilize the vertical osmotic gradient.
p.14
Mechanisms of Water Balance
How does the vertical osmotic gradient affect water balance?
It facilitates the reabsorption of water from the collecting ducts.
p.17
Integrated Control of Blood Volume and Osmolarity
What effect does increased salt intake have on blood volume?
It can lead to increased blood volume and blood pressure.
p.6
Fluid and Electrolyte Balance Concept
What are the two main compartments of body fluid volume?
Extracellular fluid (ECF) and intracellular fluid (ICF).
p.25
pH Homeostasis and Acid-Base Balance
What happens to CO2 in the proximal tubule cells?
CO2 diffuses into the cell and combines with water to form H+ and HCO3-.
p.19
Kidney Functions in Fluid Regulation
How does increased blood volume affect GFR?
It increases GFR (glomerular filtration rate).
p.8
Fluid and Electrolyte Balance Concept
What happens when fluid is taken away from the mug?
Fluid loss from the handle is turned off to prevent additional fluid loss (concentrated urine is produced).
p.18
Hormonal Regulation of Electrolytes
What is the primary function of aldosterone in the kidneys?
To facilitate the reabsorption of sodium and potassium secretion.
p.21
Integrated Control of Blood Volume and Osmolarity
Which systems are involved in the regulation of blood volume and osmolarity?
Cardiovascular, renal, and hypothalamic systems.
p.6
Fluid and Electrolyte Balance Concept
What triggers homeostatic reflexes related to fluid and electrolyte balance?
Changes in blood volume and blood pressure.
p.13
Medullary Vertical Osmotic Gradient
What is the role of the vasa recta in the kidney?
To preserve the vertical osmotic gradient while providing blood to the renal medulla.
p.22
pH Homeostasis and Acid-Base Balance
How does extracellular pH relate to intracellular pH?
Extracellular pH usually reflects intracellular pH.
p.23
pH Homeostasis and Acid-Base Balance
What is a source of acid input in the body?
Diet (e.g., fatty acids, amino acids).
p.25
pH Homeostasis and Acid-Base Balance
What is the function of glutamine in the renal process?
Glutamine is metabolized to ammonium ion (NH4+) and HCO3-.
p.19
Hormonal Regulation of Electrolytes
What happens to vasopressin levels when blood volume increases?
Vasopressin levels decrease.
p.9
Kidney Functions in Fluid Regulation
What type of fluid is reabsorbed in the distal nephron?
Variable reabsorption of water and solutes.
p.24
pH Homeostasis and Acid-Base Balance
What happens during hypoventilation?
It lowers pH by increasing CO2, which combines with H2O to produce H+ and HCO3-.
p.24
pH Homeostasis and Acid-Base Balance
What are some examples of inputs that can affect H+ levels?
Fatty acids, amino acids, CO2, lactic acid, and ketoacids.
p.27
pH Homeostasis and Acid-Base Balance
How does the polarity of type B intercalated cells differ from type A cells?
Type B cells have reversed polarity, meaning the same transport systems occur on opposite sides of the cells.
p.10
Medullary Vertical Osmotic Gradient
Which type of nephrons establish the vertical osmotic gradient?
Juxtamedullary nephrons (loop of Henle).
p.4
Fluid and Electrolyte Balance Concept
How do the lungs contribute to fluid and electrolyte balance?
They lose water and help remove H+ and HCO3- by breathing out CO2.
p.16
Hormonal Regulation of Electrolytes
What is vasopressin?
A hormone that regulates water balance in the body.
p.16
Hormonal Regulation of Electrolytes
What factors can affect the release of vasopressin?
Osmolarity, blood volume, and blood pressure.
p.12
Fluid and Electrolyte Balance Concept
What happens to urea concentration in the proximal cortical collecting duct when water moves out?
The concentration of urea increases in the duct.
p.19
Fluid and Electrolyte Balance Concept
What is the effect of increased blood volume on blood pressure?
It decreases blood pressure.
p.8
Fluid and Electrolyte Balance Concept
What occurs when extra fluid is added to the mug?
Excess fluid drains out of the handle (excreted in urine).
p.13
Integrated Control of Blood Volume and Osmolarity
Why is the function of the vasa recta important?
It prevents washing away of the concentration gradient in the kidney.
p.25
pH Homeostasis and Acid-Base Balance
What is the significance of reabsorbing HCO3-?
Reabsorbing HCO3- is crucial for maintaining acid-base balance in the body.
p.11
Medullary Vertical Osmotic Gradient
What is the final outcome of the countercurrent multiplication process?
The final vertical osmotic gradient is established.
p.17
Behavioral Mechanisms in Fluid Balance
What is the significance of thirst in fluid balance after salt ingestion?
Thirst stimulates water intake to dilute excess sodium.
p.23
pH Homeostasis and Acid-Base Balance
What role do proteins and hemoglobin play in the body?
They act as buffers in cells.
p.6
Integrated Control of Blood Volume and Osmolarity
What is the systemic response to changes in blood pressure?
It involves a stimulus, receptor, effector, and tissue response.
p.12
Hormonal Regulation of Electrolytes
How does vasopressin affect the collecting duct?
It increases the permeability of the collecting duct to urea.
p.11
Countercurrent Multiplication and Urea Recycling
How does the ascending limb establish a 200-mOsm gradient?
By pumping out NaCl to the interstitium.
p.22
pH Homeostasis and Acid-Base Balance
What is alkalosis?
A condition where pH is too high.
p.5
Ion Balance and Homeostasis
How does Na+ affect the body?
It influences extracellular fluid volume and osmolarity, affecting cell volume.
p.11
Medullary Vertical Osmotic Gradient
What two processes establish the medullary vertical osmotic gradient?
Countercurrent multiplication and urea recycling.
p.11
Countercurrent Multiplication and Urea Recycling
What is the characteristic of the descending limb in countercurrent multiplication?
It is water permeable and has no active Na+ pump.
p.9
Countercurrent Multiplication and Urea Recycling
What creates hyposmotic fluid in the nephron?
Removal of solute in the thick ascending limb.
p.13
Countercurrent Multiplication and Urea Recycling
What occurs during the ascent of the vasa recta?
Solutes diffuse back to the interstitium and water moves back into the capillaries.
p.24
pH Homeostasis and Acid-Base Balance
What is the response time for renal regulation of pH?
It is the slowest response.
p.9
Countercurrent Multiplication and Urea Recycling
What happens to isosmotic fluid leaving the proximal tubule?
It becomes progressively more concentrated in the descending limb.
p.11
Medullary Vertical Osmotic Gradient
What occurs after the 300 mOsm fluid enters from the proximal tubule?
The ascending limb pump and descending limb passive fluxes reestablish the 200-mOsm gradient.
p.22
pH Homeostasis and Acid-Base Balance
What can sustained contractions during alkalosis lead to?
Paralysis of respiratory muscles and death.
p.24
pH Homeostasis and Acid-Base Balance
What buffers are present in cells?
Proteins, hemoglobin, and phosphates.
p.25
pH Homeostasis and Acid-Base Balance
What transporters are involved in H+ and HCO3- handling in the proximal tubule?
Na+-H+ antiport and HCO3--Na+ symporter.
p.5
Fluid and Electrolyte Balance Concept
Why is water and ion balance important?
It is crucial for maintaining extracellular fluid volume and osmolarity, which affect cell volume.
p.11
Countercurrent Multiplication and Urea Recycling
What happens to water in the descending limb during countercurrent multiplication?
Water diffuses from the descending limb into the interstitial fluid.
p.15
Countercurrent Multiplication and Urea Recycling
What happens to fluid in the descending limb of the Loop of Henle?
Water is reabsorbed, resulting in progressively more concentrated fluid.
p.25
pH Homeostasis and Acid-Base Balance
What are the two pathways involved in H+ secretion and HCO3- reabsorption?
Pathway A (steps 1-5) and Pathway B (steps 6-7).
p.5
Fluid and Electrolyte Balance Concept
What systems are involved in maintaining water and ion balance?
The respiratory and cardiovascular systems, along with renal and behavioral responses.
p.5
Ion Balance and Homeostasis
What is the role of K+ in the body?
It affects cardiac and muscle function.
p.15
Kidney Functions in Fluid Regulation
What occurs in the distal tubule regarding ion and water reabsorption?
Ions are reabsorbed but no water.
p.5
Fluid and Electrolyte Balance Concept
What is mass balance in the context of fluid and electrolyte balance?
The body must maintain a balance of fluids and electrolytes to function properly.
