Podcast
Questions and Answers
What is the primary waste product eliminated by the kidneys?
What is the primary waste product eliminated by the kidneys?
Which of the following regulates red blood cell production?
Which of the following regulates red blood cell production?
How do the kidneys contribute to long-term blood pressure regulation?
How do the kidneys contribute to long-term blood pressure regulation?
What is the role of the kidneys in calcium regulation?
What is the role of the kidneys in calcium regulation?
Signup and view all the answers
During which condition do the kidneys perform gluconeogenesis?
During which condition do the kidneys perform gluconeogenesis?
Signup and view all the answers
What is the primary function of the vasa recta in the renal system?
What is the primary function of the vasa recta in the renal system?
Signup and view all the answers
Which electrolyte does the kidney NOT primarily regulate?
Which electrolyte does the kidney NOT primarily regulate?
Signup and view all the answers
Which part of the urinary bladder is primarily responsible for urine collection?
Which part of the urinary bladder is primarily responsible for urine collection?
Signup and view all the answers
What stimulates erythropoietin secretion from the kidneys?
What stimulates erythropoietin secretion from the kidneys?
Signup and view all the answers
What initiates the attrition reflex related to bladder function?
What initiates the attrition reflex related to bladder function?
Signup and view all the answers
What type of muscle is primarily found in the bladder's body and neck?
What type of muscle is primarily found in the bladder's body and neck?
Signup and view all the answers
Which function of the kidneys helps maintain electrolyte balance?
Which function of the kidneys helps maintain electrolyte balance?
Signup and view all the answers
How does the contraction of the bladder increase internal pressure?
How does the contraction of the bladder increase internal pressure?
Signup and view all the answers
Which of the following statements about the internal sphincter is correct?
Which of the following statements about the internal sphincter is correct?
Signup and view all the answers
What role do the pelvic nerves play in bladder function?
What role do the pelvic nerves play in bladder function?
Signup and view all the answers
Which nerve is primarily associated with sympathetic control of the bladder?
Which nerve is primarily associated with sympathetic control of the bladder?
Signup and view all the answers
What primarily initiates peristaltic contractions in the ureters?
What primarily initiates peristaltic contractions in the ureters?
Signup and view all the answers
How does the sympathetic nervous system affect peristaltic contractions in the ureters?
How does the sympathetic nervous system affect peristaltic contractions in the ureters?
Signup and view all the answers
What role do stretch receptors in the bladder wall play during the filling of the bladder?
What role do stretch receptors in the bladder wall play during the filling of the bladder?
Signup and view all the answers
What happens when the signals from the cortex are weaker than the signals from the bladder?
What happens when the signals from the cortex are weaker than the signals from the bladder?
Signup and view all the answers
What three processes are involved in urine excretion?
What three processes are involved in urine excretion?
Signup and view all the answers
What typically causes complete emptying of the bladder during voluntary urination?
What typically causes complete emptying of the bladder during voluntary urination?
Signup and view all the answers
How does the composition of urine change as it travels through the renal system?
How does the composition of urine change as it travels through the renal system?
Signup and view all the answers
What is one of the functions of the external sphincter during urination?
What is one of the functions of the external sphincter during urination?
Signup and view all the answers
What happens to the number of nephrons as people age?
What happens to the number of nephrons as people age?
Signup and view all the answers
Which structure encases the glomerulus?
Which structure encases the glomerulus?
Signup and view all the answers
In which part of the nephron does primary urine formation occur?
In which part of the nephron does primary urine formation occur?
Signup and view all the answers
What is a primary function of the loop of Henle?
What is a primary function of the loop of Henle?
Signup and view all the answers
Which type of nephron has short loops of Henle and resides in the outer cortex?
Which type of nephron has short loops of Henle and resides in the outer cortex?
Signup and view all the answers
What does the macula densa monitor?
What does the macula densa monitor?
Signup and view all the answers
What occurs when substances are freely filtered at the glomerular capillaries but are neither reabsorbed nor secreted?
What occurs when substances are freely filtered at the glomerular capillaries but are neither reabsorbed nor secreted?
Signup and view all the answers
Which substance is an example of being filtered and then completely reabsorbed back into the blood?
Which substance is an example of being filtered and then completely reabsorbed back into the blood?
Signup and view all the answers
How many collecting ducts are typically found in each kidney?
How many collecting ducts are typically found in each kidney?
Signup and view all the answers
In which scenario is tubular secretion particularly important?
In which scenario is tubular secretion particularly important?
Signup and view all the answers
What type of nephron is characterized by having long loops of Henle that travel deeply into the medulla?
What type of nephron is characterized by having long loops of Henle that travel deeply into the medulla?
Signup and view all the answers
What happens to substances that are filtered but only partially reabsorbed?
What happens to substances that are filtered but only partially reabsorbed?
Signup and view all the answers
What is the primary function of the hilum in the kidneys?
What is the primary function of the hilum in the kidneys?
Signup and view all the answers
Which of the following illustrates the relationship between excretion, filtration, and reabsorption?
Which of the following illustrates the relationship between excretion, filtration, and reabsorption?
Signup and view all the answers
Which of the following substances is likely to be not reabsorbed at all and is instead excreted?
Which of the following substances is likely to be not reabsorbed at all and is instead excreted?
Signup and view all the answers
Which statement correctly describes the structure of the renal medulla?
Which statement correctly describes the structure of the renal medulla?
Signup and view all the answers
What is the role of the renal pelvis in urinary function?
What is the role of the renal pelvis in urinary function?
Signup and view all the answers
What role does tubular reabsorption play in urine formation compared to secretion?
What role does tubular reabsorption play in urine formation compared to secretion?
Signup and view all the answers
What percentage of cardiac output typically flows to the kidneys?
What percentage of cardiac output typically flows to the kidneys?
Signup and view all the answers
Which of the following statements is true about solute handling in the nephron?
Which of the following statements is true about solute handling in the nephron?
Signup and view all the answers
Which structure is directly responsible for the filtration of blood in the kidneys?
Which structure is directly responsible for the filtration of blood in the kidneys?
Signup and view all the answers
What causes fluid filtration to occur at high rates in the glomerular capillaries?
What causes fluid filtration to occur at high rates in the glomerular capillaries?
Signup and view all the answers
How do the efferent and afferent arterioles contribute to renal circulation?
How do the efferent and afferent arterioles contribute to renal circulation?
Signup and view all the answers
What is the primary role of the peritubular capillaries in the kidney?
What is the primary role of the peritubular capillaries in the kidney?
Signup and view all the answers
Study Notes
Urinary System - Kidneys
- Kidneys filter plasma, remove waste, regulate water and electrolyte balance, body fluid osmolality, electrolyte concentrations, arterial pressure, acid-base balance, erythrocyte production, hormone secretion, metabolism, and excretion.
- Kidneys eliminate metabolic waste (urea, creatine, uric acid, bilirubin, hormone metabolites).
- Kidney excretion of water and electrolytes must match intake to maintain homeostasis.
- Kidneys regulate sodium, chloride, potassium, calcium, hydrogen, magnesium, and phosphate.
- Kidneys are crucial for long-term arterial blood pressure regulation.
- Kidneys help regulate short-term arterial pressure through hormone secretion and vasoactive factors.
- Kidneys, along with lungs and buffer systems, regulate acid-base balance.
- Kidneys produce erythropoietin, stimulating red blood cell production.
- Hypoxia stimulates erythropoietin secretion.
- Severe kidney disease can lead to severe anemia.
- Kidneys produce 1-5 hydroxy vitamin D3 (active vitamin D), crucial for calcium deposition and gastrointestinal calcium reabsorption.
- Kidneys perform gluconeogenesis (glucose synthesis from amino acids) during prolonged fasting.
- Two kidneys, about 150g each, lie on the posterior abdominal wall, outside the peritoneal cavity (size of a clenched fist).
- Kidney hilum is a medial indentation where renal artery, vein, lymphatics, nerves, and ureter pass.
- Kidney consists of cortex (outer) and medulla (inner).
- Medulla has 8-10 renal pyramids, whose bases are at the cortex-medulla border and papillae that open into the minor calyx.
- Minor calyces combine to form major calyces, which form the renal pelvis, leading to the ureters.
- Ureter walls contract to propel urine to the bladder.
- Blood flow to kidneys is 22% of cardiac output (about 1100 mL/min).
- Renal artery branches into interlobar, arcuate, interlobular, and afferent arterioles, leading to glomerular capillaries.
- Glomerular capillaries coalesce into efferent arterioles, leading to peritubular capillaries.
- High glomerular capillary hydrostatic pressure leads to rapid fluid filtration.
- Lower peritubular capillary hydrostatic pressure facilitates fluid reabsorption.
- Each kidney has ~800,000-1,000,000 nephrons (urine-forming units).
- Nephrons cannot regenerate; numbers decrease with age.
- A nephron consists of glomerulus and a long tubule, filtering and converting fluid to urine.
- Bowman's capsule surrounds the glomerulus, fluid enters it.
- Renal tubule (Bowman’s capsule > proximal tubule > loop of Henle > distal tubule > collecting duct) progressively modifies fluid.
- Descending/Ascending limbs of loop of Henle are thin segments.
- Macula densa cells in the distal tubule respond to salt levels in the filtrate.
- Cortical collecting ducts merge to form larger collecting ducts.
- Urine is formed through glomerular filtration, tubular reabsorption, and tubular secretion.
- Tubular reabsorption is more important than tubular secretion in urine formation.
- Certain substances are not reabsorbed and are directly excreted.
Urine Formation and Excretion
-
Glomerular filtration removes water and solutes from blood, approximately 180L/day.
-
Tubular reabsorption returns essential substances (glucose, amino acids, electrolytes) to blood.
-
Tubular secretion moves substances from blood to filtrate (e.g., H+, K+, creatinine).
-
Substances freely filtered can be reabsorbed, secreted, or neither.
-
The rate of filtration and reabsorption in most substances exceeds secretion rate.
-
Plasma volume is filtered and processed around 60 times daily.
-
Urine excretion is filtration minus reabsorption + secretion.
Urinary Bladder and Urethra
- Urinary bladder is a smooth muscle chamber with a body and a neck (connecting to urethra)
- Bladder contraction increases the pressure to 40-60 mmHg
- Smooth muscle cells fuse, creating a low resistance pathway
- Bladder is innervated by parasympathetic fibers via pelvic nerves and sympathetic fibers via hypogastric nerves.
- Stretch receptors initiate the attrition reflex.
- Attrition reflex triggers voluntary urination (inhibition of external sphincter).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the vital functions of the kidneys in this quiz, which covers how they filter plasma, regulate electrolytes, and maintain homeostasis. Understand the role of kidneys in blood pressure regulation, acid-base balance, and erythrocyte production. Test your knowledge on kidney metabolism and waste elimination processes.
