Renal Physiology Quiz
38 Questions
13 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary effect of angiotensin II on the glomerular filtration rate (GFR)?

  • It increases GFR by constricting the efferent arterioles.
  • It reduces GFR by constricting both afferent and efferent arterioles. (correct)
  • It increases GFR by dilating afferent arterioles.
  • It has no significant effect on GFR.

    • Which hormone is released in response to a sudden large increase in blood pressure?

  • Epinephrine
  • Atrial natriuretic peptide (ANP) (correct)
  • Vasopressin
  • Cortisol

    • Which mechanism is NOT involved in the reabsorption of sodium in the renal tubule cells?

  • Na⁺-Glucose Symporter in apical membrane
  • Paracellular reabsorption through tight junctions
  • Na⁺-K⁺ ATPase in basolateral membrane
  • Na⁺ channels in the epithelial membrane (correct)

    • What role do tight junctions play in the reabsorption process within the renal tubule?

    <p>They maintain selective permeability and control solute movement.</p> Signup and view all the answers

    What is the function of the sodium-potassium pump in renal tubule cells?

    <p>Ejects Na⁺ from renal tubule cells at the basolateral membrane.</p> Signup and view all the answers

    What is the primary function of antidiuretic hormone (ADH) in the kidneys?

    <p>Increases water reabsorption in the collecting duct</p> Signup and view all the answers

    Which hormone inhibits phosphate reabsorption in the proximal convoluted tubule?

    <p>Parathyroid hormone (PTH)</p> Signup and view all the answers

    In the absence of antidiuretic hormone (ADH), how do the apical membranes of principal cells in the collecting duct behave?

    <p>They are impermeable to water.</p> Signup and view all the answers

    What triggers the release of antidiuretic hormone (ADH)?

    <p>Low blood flow in the posterior pituitary</p> Signup and view all the answers

    Which hormone is responsible for promoting calcium reabsorption in the kidneys?

    <p>Parathyroid hormone (PTH)</p> Signup and view all the answers

    What is the main reason the right kidney is positioned lower than the left kidney?

    <p>The larger size of the liver above the right kidney.</p> Signup and view all the answers

    Which of the following correctly describes the renal arteries' contribution to cardiac output?

    <p>They deliver approximately 25% of cardiac output to the kidneys.</p> Signup and view all the answers

    Which component is directly responsible for the blood supply to the renal medulla?

    <p>Vasa recta</p> Signup and view all the answers

    What hormone produced by the kidneys is primarily involved in regulating red blood cell production?

    <p>Erythropoietin</p> Signup and view all the answers

    Which function of the kidneys is associated with the conversion of fats into glucose during fasting?

    <p>Gluconeogenesis</p> Signup and view all the answers

    Which of the following is NOT a primary function of the kidneys?

    <p>Production of glucagon</p> Signup and view all the answers

    The sympathetic nerve supply to the kidneys originates from which structure?

    <p>Renal plexus</p> Signup and view all the answers

    What is the function of the hormone renin in the kidneys?

    <p>To regulate blood pressure and kidney function</p> Signup and view all the answers

    What is the primary role of parathyroid hormone (PTH) in calcium homeostasis?

    <p>Enhances calcium absorption from the intestine</p> Signup and view all the answers

    What percentage of nephrons in the human kidney are cortical nephrons?

    <p>80-85%</p> Signup and view all the answers

    Which statement describes juxtamedullary nephrons?

    <p>They are primarily involved in the concentration of urine.</p> Signup and view all the answers

    What is the main function of the glomerulus within the renal corpuscle?

    <p>To filter blood and form urine</p> Signup and view all the answers

    What type of capillaries supply cortical nephrons?

    <p>Peritubular capillaries</p> Signup and view all the answers

    Which of the following substances is primarily reabsorbed rather than secreted during glomerular filtration?

    <p>Glucose</p> Signup and view all the answers

    What regulates the secretion of PTH from the parathyroid glands?

    <p>Low serum ionized calcium levels</p> Signup and view all the answers

    What is the primary transport mechanism for water reabsorption in the kidneys?

    <p>Passive transport</p> Signup and view all the answers

    What is the total amount of water filtered by the kidneys per day?

    <p>180 L</p> Signup and view all the answers

    Which segment of the nephron lacks any thin portions in its ascending limb?

    <p>Cortical nephron</p> Signup and view all the answers

    What is the primary mechanism by which glucose exits the renal tubular cells?

    <p>Facilitated diffusion into the interstitial fluid</p> Signup and view all the answers

    Which statement accurately describes the function of Na⁺-H⁺ antiporters in the proximal convoluted tubule?

    <p>They couple the transport of Na⁺ with the secretion of H⁺ into tubular fluid.</p> Signup and view all the answers

    What role does carbonic anhydrase play in the proximal convoluted tubule?

    <p>It catalyzes the production of carbonic acid from CO₂ and H₂O.</p> Signup and view all the answers

    How does the reabsorption of solutes in the proximal convoluted tubule promote water reabsorption?

    <p>By establishing an osmotic gradient that draws water into peritubular capillaries.</p> Signup and view all the answers

    What effect does K⁺ recycling from the thick ascending limb have on the interstitial fluid?

    <p>It makes the interstitial fluid more negatively charged compared to the tubular fluid.</p> Signup and view all the answers

    In the distal convoluted tubule, how is Na⁺ primarily transported into principal cells?

    <p>Via Na⁺ leakage channels in the apical membrane.</p> Signup and view all the answers

    What major change occurs in sodium levels at the end of the distal convoluted tubule?

    <p>95-100% of Na⁺ is reabsorbed back into systemic circulation.</p> Signup and view all the answers

    Which hormone is primarily responsible for regulating sodium reabsorption in the renal tubules?

    <p>Aldosterone</p> Signup and view all the answers

    What is the primary function of aquaporin-1 in the proximal convoluted tubule?

    <p>Enhance water permeability for reabsorption.</p> Signup and view all the answers

    What is the fate of K⁺ ions in principal cells of the distal convoluted tubule?

    <p>K⁺ is exclusively secreted into the tubular fluid.</p> Signup and view all the answers

    Study Notes

    Learning Objectives

    • Understand the organs and functions of the urinary system
    • Understand kidney anatomy, including location, internal and external structure, blood and nerve supply, and function
    • Understand nephron structure and blood supply organization, and function
    • Understand renal physiology including urine formation, glomerular filtration, tubular reabsorption, tubular secretion, and hormonal regulation, and homeostasis

    The Urinary System

    • Paired bean-shaped organs
    • Located along the back body wall below the diaphragm, adjacent to the vertebral column
    • Right kidney lower than the left due to the liver's position

    Kidney Structure

    • Renal cortex
    • Renal medulla
    • Renal columns
    • Renal pyramids
    • Renal papilla
    • Renal sinus
    • Renal capsule
    • Renal hilum

    Blood and Nerve Supply

    • Renal arteries deliver approximately 25% of cardiac output to the kidneys per minute.
    • Arterial and venous flow patterns inside the kidneys are similar.
    • Medullary blood supply is via vasa recta.
    • Nerve supply from renal plexus.

    Functions of the Kidney

    • Removal of toxins, metabolic wastes, and excess ions from the blood.
    • Regulation of blood volume, chemical composition, and pH
    • Gluconeogenesis during prolonged fasting
    • Endocrine functions
      • Renin: regulates blood pressure and kidney function
      • Erythropoietin: regulates red blood cell production
      • Activation of Vitamin D

    Nephron

    • Structural and functional unit of the kidney (~1 million per kidney)
    • Renal corpuscle: initial filtering component
    • Renal tubule: extends from the renal corpuscle
    • Cortical nephrons: 80-85% total, located in cortex with shallower loops
    • Juxtamedullary nephrons: 15-20% total, located in medulla with longer loops.

    Glomerular Filtration

    • Filtration of blood plasma and dissolved substances (excluding most proteins)
    • Water and other filtered substances enter Bowman's capsule
    • Approximately 20% of plasma entering glomerulus is filtered
    • Net filtration pressure (NFP): drive of filtration.
    • Glomerular blood hydrostatic pressure (GBHP) = 55 mmHg
    • Capsular hydrostatic pressure (CHP) = 15 mmHg
    • Blood colloid osmotic pressure (BCOP) = 30 mmHg
    • NFP = GBHP - CHP - BCOP = 10 mmHg

    Glomerular Filtration Regulation

    • Intrinsic mechanisms (myogenic and tubuloglomerular mechanisms)
      • Regulate GFR (glomerular filtration rate) in response to moderate BP changes
    • Extrinsic mechanisms (renin-angiotensin-aldosterone system)
      • Indirectly regulate GFR by maintaining systemic blood pressure
      • Angiotensin II is potent vasoconstrictor of arterioles, reduces GFR
    • Atrial natriuretic peptide (ANP) is released in response to high BP - relaxes glomerulus, increasing surface area for filtration

    Reabsorption Routes

    • Paracellular and transcellular processes (solutes and water move across/between tubule cells)
    • Sodium-potassium pump (Na+/K+ ATPase) drives reabsorption (6% of the body's resting ATP)

    Reabsorption in PCT (Proximal Convoluted Tubule)

    • Reabsorption of Na+, HCO3-, glucose, amino acids, water, Ca2+, and Mg2+
    • Driven by electrochemical gradients (facilitated diffusion) & active transport of Na+
    • Na+/glucose cotransporter reabsorbs virtually all filtered glucose
    • Na+/H+ exchange and carbonic anhydrase support HCO3- reabsorption
      • Additional solutes, also passively (or actively) reabsorbed

    Reabsorption in other Tubules

    • Reabsorption of water, Na+, K+, Cl-, and other solutes at different locations in the nephron loop and distal convoluted tubule
    • Controlled by hormones (ADH, aldosterone, etc.)
    • These processes are in response to regulate pH, electrolyte concentrations, and fluid volume

    Hormones and Homeostasis

    • Several hormones (Angiotensin II, Antidiuretic hormone [ADH], Aldosterone, Atrial Natriuretic Peptide [ANP], and parathyroid hormone [PTH])
    • Regulate reabsorption of water and electrolytes - maintain homeostasis through regulation of blood pressure, volume, and electrolyte balance.
    • Hormones work in concert to regulate urine production.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    The Renal System 1-2 PDF

    Description

    Test your understanding of renal physiology with this quiz! Questions cover the roles of various hormones, mechanisms of reabsorption, and anatomical differences in the kidneys. Perfect for students studying renal function and physiology.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser