Podcast
Questions and Answers
What is the primary function of Bowman's capsule?
What is the primary function of Bowman's capsule?
Which structure is responsible for preventing proteins from being filtered into the glomerular filtrate?
Which structure is responsible for preventing proteins from being filtered into the glomerular filtrate?
What is the condition called when there is an abnormal amount of proteins present in the urine?
What is the condition called when there is an abnormal amount of proteins present in the urine?
Which layer of Bowman's capsule directly surrounds the glomerular capillaries?
Which layer of Bowman's capsule directly surrounds the glomerular capillaries?
Signup and view all the answers
Which of the following is NOT a physical barrier that the glomerular filtrate passes through?
Which of the following is NOT a physical barrier that the glomerular filtrate passes through?
Signup and view all the answers
Sodium reabsorption primarily occurs in the distal convoluted tubule.
Sodium reabsorption primarily occurs in the distal convoluted tubule.
Signup and view all the answers
The renin-angiotensin-aldosterone system helps regulate blood pressure by increasing sodium reabsorption in the kidneys.
The renin-angiotensin-aldosterone system helps regulate blood pressure by increasing sodium reabsorption in the kidneys.
Signup and view all the answers
Tubular reabsorption involves the movement of substances from the blood into the renal tubules.
Tubular reabsorption involves the movement of substances from the blood into the renal tubules.
Signup and view all the answers
Proximal convoluted tubules are responsible for the reabsorption of glucose, amino acids, and bicarbonate.
Proximal convoluted tubules are responsible for the reabsorption of glucose, amino acids, and bicarbonate.
Signup and view all the answers
Tubular transport in the kidneys is a passive process that does not require energy.
Tubular transport in the kidneys is a passive process that does not require energy.
Signup and view all the answers
Sodium reabsorption mainly occurs in the distal tubule.
Sodium reabsorption mainly occurs in the distal tubule.
Signup and view all the answers
The proximal convoluted tubule is more involved in water reabsorption than in salt reabsorption.
The proximal convoluted tubule is more involved in water reabsorption than in salt reabsorption.
Signup and view all the answers
The loop of Henle is responsible for selective tubular reabsorption.
The loop of Henle is responsible for selective tubular reabsorption.
Signup and view all the answers
The renin-angiotensin-aldosterone system plays a role in decreasing blood pressure.
The renin-angiotensin-aldosterone system plays a role in decreasing blood pressure.
Signup and view all the answers
Proximal tubules are responsible for the majority of water reabsorption in the nephron.
Proximal tubules are responsible for the majority of water reabsorption in the nephron.
Signup and view all the answers
Tubular transport involves the movement of substances across the nephron's capillaries.
Tubular transport involves the movement of substances across the nephron's capillaries.
Signup and view all the answers
Selective tubular secretion involves the transfer of substances from the blood to the tubules for elimination.
Selective tubular secretion involves the transfer of substances from the blood to the tubules for elimination.
Signup and view all the answers
Glucose and amino acids in the initial filtrate are reabsorbed by the proximal tubule through primary active transport.
Glucose and amino acids in the initial filtrate are reabsorbed by the proximal tubule through primary active transport.
Signup and view all the answers
The reabsorption of glucose and amino acids depends on the potassium gradient across the apical cell membranes of the epithelial cells.
The reabsorption of glucose and amino acids depends on the potassium gradient across the apical cell membranes of the epithelial cells.
Signup and view all the answers
Aldosterone can cause 100% retention of sodium in the body.
Aldosterone can cause 100% retention of sodium in the body.
Signup and view all the answers
Natriuretic peptide stimulates sodium reabsorption in the distal and collecting tubules.
Natriuretic peptide stimulates sodium reabsorption in the distal and collecting tubules.
Signup and view all the answers
In the absence of aldosterone, 20mg of sodium per day may be excreted from the body.
In the absence of aldosterone, 20mg of sodium per day may be excreted from the body.
Signup and view all the answers
A fall in NaCl, extracellular fluid volume, and arterial blood pressure stimulates the renin-angiotensin-aldosterone system.
A fall in NaCl, extracellular fluid volume, and arterial blood pressure stimulates the renin-angiotensin-aldosterone system.
Signup and view all the answers
Atrial Naturetic Peptide (ANP) stimulates sodium reabsorption in the distal tubules.
Atrial Naturetic Peptide (ANP) stimulates sodium reabsorption in the distal tubules.
Signup and view all the answers
Ace Inhibitors cause loss of water by promoting salt reabsorption.
Ace Inhibitors cause loss of water by promoting salt reabsorption.
Signup and view all the answers
Glucose reabsorption has a tubular maximum that is reached when the plasma concentration of glucose exceeds 300mg/100 ml.
Glucose reabsorption has a tubular maximum that is reached when the plasma concentration of glucose exceeds 300mg/100 ml.
Signup and view all the answers
Renal threshold is the maximum amount of glucose that can be reabsorbed by the kidneys.
Renal threshold is the maximum amount of glucose that can be reabsorbed by the kidneys.
Signup and view all the answers
Study Notes
Glomerular Filtration
- The effective filtration pressure is the difference between the blood (hydrostatic) pressure in the capillary and the osmotic pressure generated by the plasma proteins of the blood.
- Hydrostatic pressure in the urinary space of Bowman's capsule and osmotic pressure generated by proteins in the fluid can also be factors, becoming important in disease states.
Glomerular Filtration Rate (GFR) and Renal Blood Flow (RBF)
- In normally hydrated mammals, GFR and RBF remain relatively stable despite minor short-term fluctuations in arterial blood pressure.
- This stability is maintained by mechanisms intrinsic to the kidney, known as renal autoregulation.
Tubular Reabsorption
- 99% of water is reabsorbed, 99.5% of sodium is reabsorbed, 50% of urea is reabsorbed, and phenol is not reabsorbed.
- Proximal convoluted tubule cells are cuboidal, with a luminal border modified with microvilli (brush border).
- Glucose and amino acids are reabsorbed from the filtrate by cells of the proximal tubule.
Glomerular Filtration Barrier
- The glomerular filtration barrier acts like a sieve, allowing all substances up to a molecular weight of about 65,000 daltons to pass through.
- Blood cells are too large to pass, and only a small percentage of plasma proteins pass through the barrier.
- Most other plasma constituents, such as glucose, amino acids, urea, creatinine, sodium, potassium, chlorine, and bicarbonate ions, readily cross the barrier.
Proteinuria and Hematuria
- Proteinuria is the presence of abnormal amounts of protein in voided urine.
- Kidney diseases that localize in or primarily affect glomeruli are often associated with proteinuria or hematuria (blood in voided urine).
Forces Involved in Glomerular Filtration
- The forces determining the rate of movement of fluid across the glomerular filtration barrier are:
- Glomerular capillary blood pressure (mmHg)
- Plasma colloid osmotic pressure
- Bowman's capsule hydrostatic pressure
- Net filtration pressure
Renal Processes
- Three basic renal processes:
- Glomerular filtration: filtering of blood into tubule forming the primitive urine
- Selective tubular reabsorption: absorption of substances needed by the body from tubule to blood
- Selective tubular secretion: secretion of substances to be eliminated from the body into the tubule from the blood
Urine Formation
- Urine formation occurs in the kidneys, and by adjusting the volume and composition of urine in response to changes in dietary intake or metabolism, the kidneys regulate the body balance of water, electrolytes, acids, and bases.
- Signs of kidney diseases include imbalances of water, electrolytes, acids, and bases, and increases in blood levels of urea and creatinine.
The Urinary System
- The urinary system consists of:
- Kidneys
- Blood supply: renal arteries and veins
- Ureter
- Urinary bladder
- Urethra
The Nephron
- The nephron is the functional unit of the kidney, consisting of:
- Bowman's capsule
- Glomerulus
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
- Nephrons in all mammalian kidneys are similar in basic structure and function, but the number of nephrons differs among mammals.
Functions of the Kidney
- The kidney regulates:
- Water balance
- Electrolyte balance
- Plasma volume
- Acid-base balance
- Osmolarity balance
- Excretion
- Hormone secretion
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the factors affecting effective filtration pressure in capillaries, including blood pressure, osmotic pressure, and disease states. Learn about the role of hydrostatic pressure and osmotic pressure in capillary filtration.
