WorksheetsExam 4 Prep - Respiratory & Kidneys
Total questions: 24
Worksheet time: 24mins
In systemic capillaries, which process describes the chloride shift?
HCO₃⁻ moves into red blood cells in exchange for Cl⁻ moving out.
HCO₃⁻ moves out of red blood cells in exchange for Cl⁻ moving in.
Cl⁻ moves out of red blood cells in exchange for H⁺ moving in.
Cl⁻ and HCO₃⁻ move together out of red blood cells without exchange.
Which enzyme in red blood cells catalyzes the reaction that produces HCO₃⁻ for the chloride shift?
Hemoglobin
Carbonic anhydrase
Carbonic acid
Glucokinase
What is the primary purpose of the chloride shift during CO₂ transport?
To transport O₂ more efficiently to tissues
To buffer pH changes in plasma by exchanging H⁺ for Cl⁻
To maintain electrical neutrality when HCO₃⁻ leaves the red blood cell
To increase CO₂ solubility in plasma by forming carbonic acid
In pulmonary capillaries, the reverse chloride shift occurs because:
CO₂ production in RBCs far exceeds diffusion into alveolar air
HCO₃⁻ re-enters RBCs in exchange for Cl⁻ exiting, facilitating CO₂ release
Cl⁻ moves into RBCs to form carbaminohemoglobin directly
O₂ binding to hemoglobin forces Cl⁻ out independently of HCO₃⁻
Which statement correctly describes CO₂ transport in blood?
All CO₂ is carried dissolved in plasma due to its high solubility.
CO₂ combines with plasma proteins but does not enter RBCs.
Approximately 70% of CO₂ is converted to HCO₃⁻ in RBCs, with much exchanged via the chloride shift.
CO₂ binds exclusively to the heme portion of hemoglobin, displacing O₂.
During vigorous exercise, what change in the chloride shift would you expect in systemic capillaries?
Decreased HCO₃⁻ formation and reduced Cl⁻ uptake by RBCs
Increased HCO₃⁻ formation and increased Cl⁻ uptake by RBCs
No change in HCO₃⁻ formation but increased Cl⁻ efflux
Increased HCO₃⁻ formation with simultaneous Cl⁻ moving out of RBCs
Which of the following best describes how medullary chemoreceptors regulate ventilation?
They respond to arterial PO₂ changes and directly alter respiratory rate.
They detect changes in cerebrospinal fluid pH (reflecting CO₂ levels) and adjust ventilation accordingly.
They sense changes in arterial blood glucose and influence ventilation.
They monitor atrial stretch and modify depth of breathing.
Hypoventilation results in which of the following blood gas changes?
↓ PCO₂, ↑ pH (alkalosis)
↑ PCO₂, ↓ pH (acidosis)
↓ PO₂, ↑ pH (alkalosis)
↑ PO₂, ↑ pH (alkalosis)
One likely cause of acute respiratory alkalosis is:
Hypoventilation due to neuromuscular disease.
Hyperventilation from anxiety or pain.
COPD exacerbation leading to CO₂ retention.
Inhalation of CO₂-enriched air.
In the context of respiratory physiology, regulation of blood pH primarily occurs in:
The alveolar macrophages.
The sinoatrial node of the heart.
The lungs (via ventilation) and kidneys (via HCO₃⁻ reabsorption/secretion).
The hepatic portal system through urea synthesis.
During the chloride shift:
Cl⁻ moves out of red blood cells to balance HCO₃⁻ entry.
HCO₃⁻ moves into red blood cells while Cl⁻ moves out.
HCO₃⁻ moves out of red blood cells in exchange for Cl⁻ entering.
Cl⁻ binds to hemoglobin, triggering CO₂ release.
A 30-year-old woman holds her breath for 60 seconds. Which of these changes occurs first to stimulate her urge to breathe?
Decrease in arterial PO₂ below 60 mmHg
Increase in PCO₂ leading to lowered CSF pH sensed by central chemoreceptors
Drop in arterial pH due to lactic acid buildup
Rise in arterial pH due to decreased CO₂ levels
What is one of the three processes involved in urine production?
Endocytosis
Exocytosis
Filtration at the glomerulus
Diffusion across skin
How does ADH promote water recovery in the collecting duct?
By increasing sodium secretion into urine
By activating the sodium-potassium pump in the loop of Henle
By inserting aquaporin-2 channels into principal cell membranes, increasing water permeability
By stimulating urea secretion into the medullary interstitium
Which segment of the nephron is impermeable to water?
Descending limb of loop of Henle
Thick ascending limb of loop of Henle
Proximal convoluted tubule
Collecting duct in presence of ADH
A patient taking an ACE inhibitor experiences low blood pressure. Which kidney function is most directly affected by this drug?
Erythropoietin production
Formation of filtrate
Aldosterone-mediated sodium reabsorption
Urea recycling
In the proximal convoluted tubule, what mechanism reabsorbs glucose?
Secondary active transport via sodium-glucose cotransporters
Facilitated diffusion through aquaporin channels
Passive diffusion through lipid bilayer
Endocytosis
During dehydration, what change in kidney function helps conserve water?
Increased GFR to eliminate solutes
Reduced secretion of renin
Increased ADH release leading to increased aquaporin expression and water reabsorption
Increased H⁺ secretion leading to acidic urine
Respiratory acidosis occurs when:
↓ PCO₂ → ↑ blood pH
↑ PCO₂ → ↓ blood pH
↑ HCO₃⁻ → ↓ blood pH
↓ H⁺ secretion by kidneys → ↑ blood pH
In chronic respiratory acidosis, the kidneys compensate by:
Decreasing HCO₃⁻ reabsorption and increasing H⁺ secretion
Increasing H⁺ secretion only
Increasing HCO₃⁻ reabsorption and generating new HCO₃⁻
Decreasing ammoniagenesis in proximal tubules
Hyperventilation most directly causes:
Increased renal HCO₃⁻ reabsorption → metabolic alkalosis
↓ PCO₂ → ↑ blood pH (respiratory alkalosis)
↓ HCO₃⁻ secretion → metabolic acidosis
↑ PCO₂ → ↓ blood pH (respiratory acidosis)
If a patient blows off CO₂ (hyperventilates), the expected immediate change in blood pH is:
Decrease in pH (more acidic)
Increase in pH (more alkaline)
No change in pH
Variable, depending on renal function
Metabolic acidosis (e.g., from diabetic ketoacidosis) triggers respiratory compensation by:
Decreasing tidal volume to retain CO₂
Increasing respiratory rate to blow off CO₂
Decreasing HCO₃⁻ reabsorption in kidneys
Increasing renal H⁺ secretion
In metabolic alkalosis, the kidneys help normalize pH by:
Increasing HCO₃⁻ reabsorption and decreasing H⁺ secretion
Decreasing HCO₃⁻ reabsorption and increasing H⁺ secretion
Increasing ammoniagenesis to generate more HCO₃⁻
Excreting less H⁺ into urine
