p.1
Regulation of Plasma Volume and Blood Pressure
How does the urinary system regulate plasma volume and blood pressure?
By controlling the rate at which water is excreted in the urine.
p.23
Glomerular Filtration and Influencing Factors
How can GFR (180 L/day) stay constant over a wide range of arterial blood pressure (80-180 mm Hg)?
Through two intrinsic autoregulatory mechanisms: myogenic response and tubuloglomerular feedback.
p.33
Reabsorption and Secretion Processes in the Nephron
How is the transport rate of glucose related to plasma glucose concentration?
The transport rate is directly proportional to the plasma glucose concentration until the transport maximum is reached.
p.15
Vascular Elements of the Kidney
What are the main vascular elements involved in the filtration process in the kidney?
Afferent arteriole, glomerulus, efferent arteriole, and peritubular capillaries.
p.8
Vascular Elements of the Kidney
What role do the peritubular capillaries play in the nephron?
Peritubular capillaries surround the tubule and are involved in the reabsorption and secretion processes.
p.7
Vascular Elements of the Kidney
What is the function of the portal system in the kidney?
The portal system in the kidney involves the flow of blood from afferent arterioles to the glomerulus, then to efferent arterioles, and finally to peritubular capillaries and the vasa recta in the medulla.
p.23
Glomerular Filtration and Influencing Factors
What is tubuloglomerular feedback?
It is a paracrine control mechanism on the fluid flow through the loop of Henle.
p.5
Kidney Anatomy and Structure
What are the two main regions of the kidney?
The outer cortex and the inner medulla.
p.8
Vascular Elements of the Kidney
What is the vasa recta and its function in the nephron?
The vasa recta are capillaries that run parallel to the loop of Henle and are involved in the concentration of urine.
p.32
Reabsorption and Secretion Processes in the Nephron
What is required for solutes to be reabsorbed or transported from filtrate to plasma across the tubular epithelium?
The use of carrier proteins.
p.7
Vascular Elements of the Kidney
What is the vasa recta?
The vasa recta are capillaries in the medulla of the kidney that are part of the portal system.
p.17
Glomerular Filtration and Influencing Factors
What remains in the capillary during glomerular filtration?
Blood cells and plasma proteins.
p.16
Tubular Structure and Function of Nephrons
How does the filtrate osmolarity change in the distal tubule and collecting duct?
The filtrate osmolarity can vary in the distal tubule and collecting duct depending on the body's hydration status and the action of hormones like ADH.
p.4
Kidney Anatomy and Structure
What is the position of the kidneys relative to the peritoneal cavity?
The kidneys lie behind the peritoneal cavity (retroperitoneal).
p.3
Kidney Anatomy and Structure
What are the accessory structures of the urinary system?
Ureter, urinary bladder, and urethra.
p.3
Kidney Anatomy and Structure
What is the function of the urethra in the urinary system?
To carry urine from the urinary bladder to the outside of the body.
p.5
Kidney Anatomy and Structure
What is the function of the renal pelvis?
It collects urine from the nephrons before it flows into the ureter.
p.7
Vascular Elements of the Kidney
What are the peritubular capillaries?
Peritubular capillaries are capillaries that surround the tubule in the kidney.
p.30
Reabsorption and Secretion Processes in the Nephron
What is the role of the SGLT protein in glucose reabsorption?
The SGLT protein uses the electrochemical gradient of Na+ to pull glucose into the cell against its concentration gradient.
p.19
Glomerular Filtration and Influencing Factors
What do the foot processes of podocytes do?
They wrap around the endothelium with filtration slits.
p.6
Nephrons as Functional Units of the Kidney
What is the primary function of both cortical and juxtamedullary nephrons?
Both are involved in urine formation.
p.28
Reabsorption and Secretion Processes in the Nephron
How does water move during solute reabsorption in the nephron?
Water moves by osmosis, following solute reabsorption.
p.28
Reabsorption and Secretion Processes in the Nephron
What is the similarity between filtrate and interstitial fluid?
Filtrate is similar to interstitial fluid.
p.28
Reabsorption and Secretion Processes in the Nephron
What does epithelial transport involve in the nephron?
Substances crossing both the apical and basolateral membranes.
p.20
Glomerular Filtration and Influencing Factors
How does the hydrostatic pressure of fluid in Bowman's capsule (P fluid) affect glomerular filtration?
It creates a hydrostatic fluid pressure that favors fluid moving back into the glomerular capillaries.
p.4
Kidney Anatomy and Structure
What structures emerge from the concave surface of the kidney?
Renal blood vessels, nerves, and ureters.
p.18
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the nephron?
The afferent arteriole supplies blood to the glomerulus for filtration.
p.3
Kidney Anatomy and Structure
What are the main components of the urinary system?
The kidneys and accessory structures.
p.10
Vascular Elements of the Kidney
What are the two specialized cells in the juxtaglomerular apparatus?
Macula densa cells and Granular cells.
p.26
Glomerular Filtration and Influencing Factors
When do sympathetic neurons play an important role in controlling GFR?
When MAP falls below 80 mm Hg, such as in severe dehydration or hemorrhage.
p.32
Reabsorption and Secretion Processes in the Nephron
What does the transport maximum (Tm) indicate?
The rate of transport at saturation.
p.19
Glomerular Filtration and Influencing Factors
What type of surface charge do the pores in the endothelium have?
Negative-charged protein.
p.19
Glomerular Filtration and Influencing Factors
How is the epithelium in the urinary system modified?
It is modified into podocytes.
p.28
Reabsorption and Secretion Processes in the Nephron
What drives anion reabsorption in the nephron?
The electrochemical gradient drives anion reabsorption.
p.22
Glomerular Filtration and Influencing Factors
What is the glomerular filtration rate (GFR)?
The volume of fluid that filters into the Bowman's capsule per unit time.
p.30
Reabsorption and Secretion Processes in the Nephron
What is the similarity between filtrate and interstitial fluid in the proximal tubule?
Filtrate is similar to interstitial fluid.
p.22
Glomerular Filtration and Influencing Factors
What does the filtration coefficient depend on?
The surface area of the glomerular capillaries available for filtration and the permeability of the interface between the capillary and Bowman's capsule.
p.4
Kidney Anatomy and Structure
Where are the kidneys located in the body?
On either side of the spine at the level of the eleventh and twelfth ribs.
p.18
Glomerular Filtration and Influencing Factors
What are the three filtration barriers substances pass through before entering the tubule lumen?
Glomerular capillary endothelium, basal lamina, and epithelium of Bowman's capsule.
p.37
Vascular Elements of the Kidney
What is the role of the afferent arteriole in the kidney?
The afferent arteriole supplies blood to the glomerulus for filtration.
p.3
Kidney Anatomy and Structure
What is the function of the ureter in the urinary system?
To transport urine from the kidneys to the urinary bladder.
p.26
Vascular Elements of the Kidney
What effect does the innervation of α-receptors on vascular smooth muscle have?
It causes vasoconstriction.
p.5
Kidney Anatomy and Structure
What is the capsule in the context of kidney anatomy?
The capsule is the outer covering of the kidney.
p.29
Reabsorption and Secretion Processes in the Nephron
How does the ion composition of filtrate entering the proximal tubules compare to plasma?
It is similar in ion composition to plasma.
p.19
Glomerular Filtration and Influencing Factors
What is the basal lamina composed of?
An acellular layer of extracellular matrix with negative-charged glycoprotein.
p.9
Tubular Structure and Function of Nephrons
What are the three parts of the Loop of Henle?
Thin descending limb, thin ascending limb, and thick ascending limb.
p.20
Glomerular Filtration and Influencing Factors
How does hydrostatic pressure of blood (P H) influence glomerular filtration?
It forces fluid through the leaky endothelium into Bowman's capsule, favoring filtration.
p.36
Reabsorption and Secretion Processes in the Nephron
Which part of the nephron is primarily responsible for secretion?
The distal convoluted tubule and the collecting duct are primarily responsible for secretion.
p.21
Glomerular Filtration and Influencing Factors
What is the glomerulus?
The glomerulus is a network of capillaries involved in the filtration of blood in the kidney.
p.23
Glomerular Filtration and Influencing Factors
What is the myogenic response in the context of GFR regulation?
It is an intrinsic ability of vascular smooth muscle to respond to pressure changes.
p.33
Reabsorption and Secretion Processes in the Nephron
What happens to glucose transport rate when the transport maximum is reached?
The transport rate levels off and no longer increases with plasma glucose concentration.
p.8
Vascular Elements of the Kidney
What is the function of the glomerulus in the nephron?
The glomerulus is a ball-like network of capillaries involved in the filtration of blood.
p.15
Excretion and Urine Output Variability
Where does the filtrate go after passing through the tubule?
To the bladder and external environment.
p.29
Reabsorption and Secretion Processes in the Nephron
What is the primary driving force for most renal reabsorption?
Active transport of sodium (Na+-K+-ATPase).
p.10
Vascular Elements of the Kidney
What is the role of granular cells in the juxtaglomerular apparatus?
They are specialized smooth muscle cells that secrete renin to regulate salt and water balance.
p.29
Reabsorption and Secretion Processes in the Nephron
How does sodium (Na+) enter the proximal tubule cells?
Through membrane proteins, moving down its electrochemical gradient.
p.16
Tubular Structure and Function of Nephrons
How does the osmolarity of the filtrate change in the proximal tubule?
In the proximal tubule, the osmolarity of the filtrate remains relatively constant as water and solutes are reabsorbed in equal proportions.
p.9
Tubular Structure and Function of Nephrons
Where does the descending limb of the Loop of Henle begin?
In the cortex, extending into the medulla.
p.19
Glomerular Filtration and Influencing Factors
What structures are involved in the filtration process in the glomerulus?
Endothelial pores, basal lamina, and podocyte foot processes.
p.28
Reabsorption and Secretion Processes in the Nephron
What are the two pathways for tubular reabsorption of solutes?
Epithelial transport (transcellular transport) and paracellular pathway.
p.36
Reabsorption and Secretion Processes in the Nephron
Where does most reabsorption occur in the nephron?
Most reabsorption occurs in the proximal convoluted tubule.
p.4
Kidney Anatomy and Structure
Which surface of the kidney faces the spine?
The concave surface of each kidney.
p.4
Vascular Elements of the Kidney
Which arteries supply blood to the kidneys?
Renal arteries, which branch off the abdominal aorta.
p.37
Vascular Elements of the Kidney
What is the role of peritubular capillaries in the kidney?
Peritubular capillaries are involved in the reabsorption and secretion processes, exchanging substances between the blood and the lumen.
p.37
Kidney Anatomy and Structure
What is the role of Bowman's capsule in the kidney?
Bowman's capsule encases the glomerulus and collects the filtrate that will become urine.
p.33
Reabsorption and Secretion Processes in the Nephron
How is the filtration of glucose related to plasma glucose concentration?
Filtration of glucose is directly proportional to the plasma glucose concentration.
p.3
Kidney Anatomy and Structure
What is the role of the urinary bladder?
To store urine until it is excreted.
p.32
Reabsorption and Secretion Processes in the Nephron
What happens when saturation occurs in the renal transport system?
All carrier proteins in the system are occupied by the substrate.
p.16
Tubular Structure and Function of Nephrons
What happens to the filtrate volume as it moves along the nephron?
The filtrate volume decreases as it moves along the nephron due to reabsorption of water and solutes.
p.16
Tubular Structure and Function of Nephrons
What is the osmolarity of the filtrate in the descending limb of the loop of Henle?
The osmolarity of the filtrate increases in the descending limb of the loop of Henle due to the reabsorption of water.
p.19
Glomerular Filtration and Influencing Factors
What is the role of the filtration slits in the glomerulus?
They allow filtered substances to pass through into the tubule lumen.
p.28
Reabsorption and Secretion Processes in the Nephron
What happens to the concentration of other solutes as fluid volume in the lumen decreases?
The concentrations of other solutes increase.
p.22
Glomerular Filtration and Influencing Factors
Does GFR stay constant over a wide range of blood pressure?
Yes, GFR stays constant over a wide range of blood pressure.
p.37
Tubular Structure and Function of Nephrons
What is the function of the collecting duct in the urinary system?
The collecting duct is involved in the excretion process, moving substances from the lumen to the external environment.
p.36
Reabsorption and Secretion Processes in the Nephron
What role does the loop of Henle play in reabsorption?
The loop of Henle plays a crucial role in concentrating urine by reabsorbing water and salts, particularly sodium and chloride.
p.2
Plasma Ion Balance and Kidney Function
How does the urinary system regulate plasma pH?
By regulating bicarbonate and hydrogen ions in the plasma.
p.31
Reabsorption and Secretion Processes in the Nephron
How can urea move across the epithelium in the proximal tubules?
Urea can move across the epithelium by diffusion if there is a concentration gradient.
p.2
Excretion and Urine Output Variability
What are some examples of metabolic wastes removed by the kidneys?
Creatinine, urea, and uric acid.
p.11
Tubular Structure and Function of Nephrons
What is the role of the Loop of Henle in the nephron?
The Loop of Henle concentrates the urine by reabsorbing water and salts.
p.8
Vascular Elements of the Kidney
What is the sequence of the vascular elements in the nephron's portal system?
Afferent arterioles → Glomerulus → Efferent arteriole → Peritubular capillaries → Vasa recta
p.24
Glomerular Filtration and Influencing Factors
What is the result of muscle cell depolarization in the myogenic response?
Voltage-gated calcium channels open.
p.7
Vascular Elements of the Kidney
What is the glomerulus?
The glomerulus is a ball-like network of capillaries within the kidney.
p.26
Regulation of Plasma Volume and Blood Pressure
What is the role of Angiotensin II in the urinary system?
It acts as a potent vasoconstrictor.
p.17
Glomerular Filtration and Influencing Factors
What is glomerular filtrate composed of?
Water and dissolved solutes.
p.6
Nephrons as Functional Units of the Kidney
How many nephrons are there per kidney?
1 million nephrons per kidney.
p.30
Reabsorption and Secretion Processes in the Nephron
How does glucose exit the proximal tubule cell?
Glucose diffuses out the basolateral side of the cell using the GLUT protein.
p.6
Nephrons as Functional Units of the Kidney
What additional function do juxtamedullary nephrons have?
They maintain an osmotic gradient in the medulla, crucial for the production of concentrated urine when water constraint occurs in the body.
p.19
Glomerular Filtration and Influencing Factors
What is the function of the mesangial cells in the glomerulus?
They provide structural support and regulate blood flow.
p.20
Glomerular Filtration and Influencing Factors
What is the osmotic pressure gradient in the glomerular capillaries and how does it influence fluid movement?
The osmotic pressure gradient is about 30 mm Hg and it favors fluid moving back into the capillaries.
p.37
Excretion and Urine Output Variability
What is the formula for excretion rate in the urinary system?
Excretion rate = filtration - reabsorption + secretion
p.18
Glomerular Filtration and Influencing Factors
What is the function of the podocyte in the glomerulus?
Podocytes form filtration slits that act as a barrier during glomerular filtration.
p.18
Glomerular Filtration and Influencing Factors
What is the lumen of Bowman's capsule?
The space within Bowman's capsule where filtered material collects before entering the proximal tubule.
p.31
Reabsorption and Secretion Processes in the Nephron
Are there active transporters for urea reabsorption in the proximal tubules?
No, there are no active transporters for urea reabsorption in the proximal tubules.
p.37
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule?
The proximal tubule is involved in the reabsorption of nutrients, ions, and water from the lumen back to the blood.
p.31
Reabsorption and Secretion Processes in the Nephron
What is the initial concentration of urea in the filtrate compared to the plasma?
The urea concentration in the filtrate and the plasma are equal in the initial stage.
p.31
Reabsorption and Secretion Processes in the Nephron
What role does water play in establishing the concentration gradient of urea in the proximal tubule?
Water moves from the lumen across the epithelium by osmosis, following the osmotic gradient created by the reabsorption of Na+ and other solutes, which increases the concentration of urea in the filtrate.
p.34
Reabsorption and Secretion Processes in the Nephron
What happens when the plasma concentration of glucose exceeds the renal threshold?
Glucose starts to appear in the urine.
p.15
Reabsorption and Secretion Processes in the Nephron
What is the formula for the amount of solute excreted in urine?
Amount excreted = Amount filtered - Amount reabsorbed + Amount secreted.
p.24
Glomerular Filtration and Influencing Factors
What triggers the myogenic response in the urinary system?
The stretch of smooth muscle.
p.10
Vascular Elements of the Kidney
What is the function of macula densa cells?
They sense the flow in the distal tubule and release paracrine factors that affect the diameter of the afferent arteriole.
p.26
Glomerular Filtration and Influencing Factors
What is the role of Prostaglandins in the urinary system?
They act as vasodilators and adjust the size of glomerular filtration slits by acting on podocytes.
p.29
Reabsorption and Secretion Processes in the Nephron
What is the concentration of sodium (Na+) in the filtrate compared to the proximal tubule cells?
The concentration of Na+ in the filtrate is higher than that in the proximal tubule cells.
p.6
Nephrons as Functional Units of the Kidney
Where are most nephrons located within the kidney?
80% of nephrons are almost contained within the cortex, known as cortical nephrons.
p.17
Glomerular Filtration and Influencing Factors
What is the filtration fraction?
The percentage of total plasma volume that filters into the tubule.
p.19
Glomerular Filtration and Influencing Factors
Through which structures do filtered substances pass to enter the tubule lumen?
Endothelial pores and filtration slits.
p.30
Reabsorption and Secretion Processes in the Nephron
What substances are reabsorbed by the active transport of sodium in the proximal tubule?
Substances such as glucose, amino acids, ions, and organic molecules are reabsorbed.
p.30
Reabsorption and Secretion Processes in the Nephron
What is the difference between SGLT and GLUT proteins?
SGLT is a secondary active transporter that uses Na+ gradient to transport glucose into the cell, while GLUT is a facilitated diffusion carrier that allows glucose to exit the cell.
p.36
Reabsorption and Secretion Processes in the Nephron
What is secretion in the urinary system?
Secretion is the process by which the kidneys actively transport waste products and excess substances from the blood into the filtrate to be excreted as urine.
p.36
Reabsorption and Secretion Processes in the Nephron
Which substances are commonly reabsorbed by the kidneys?
Commonly reabsorbed substances include water, glucose, amino acids, and various ions such as sodium, potassium, and chloride.
p.36
Reabsorption and Secretion Processes in the Nephron
How does the process of secretion help maintain homeostasis?
Secretion helps maintain homeostasis by removing excess ions, toxins, and waste products from the blood, thereby regulating the body's chemical balance.
p.14
Glomerular Filtration and Influencing Factors
What is the role of the glomerulus in the nephron?
It is involved in the filtration process, where blood is filtered into the lumen.
p.37
Vascular Elements of the Kidney
What is the role of the efferent arteriole in the kidney?
The efferent arteriole carries blood away from the glomerulus after filtration.
p.37
Glomerular Filtration and Influencing Factors
What is the function of the glomerulus?
The glomerulus is responsible for the filtration of blood to form urine.
p.2
Excretion and Urine Output Variability
What is one of the primary functions of the kidneys?
To remove metabolic wastes and foreign substances from the body.
p.31
Reabsorption and Secretion Processes in the Nephron
How does urea leave the lumen and enter the interstitial fluid?
Urea uses facilitated diffusion transporters to leave the lumen and enter the interstitial fluid.
p.21
Glomerular Filtration and Influencing Factors
What is the fluid pressure (P_fluid) in Bowman's capsule?
The fluid pressure (P_fluid) in Bowman's capsule is 15 mm Hg.
p.12
Tubular Structure and Function of Nephrons
What is the function of the collecting duct in the nephron?
The collecting duct collects urine from multiple nephrons and transports it to the renal pelvis.
p.24
Glomerular Filtration and Influencing Factors
How can GFR (180 L/day) stay constant over a wide range of arterial blood pressure (80-180 mm Hg)?
Through the myogenic response.
p.32
Reabsorption and Secretion Processes in the Nephron
What is the renal threshold?
The plasma concentration at which saturation occurs.
p.32
Reabsorption and Secretion Processes in the Nephron
What is the transport maximum (Tm)?
The transport rate at saturation.
p.16
Tubular Structure and Function of Nephrons
What happens to the osmolarity of the filtrate in the ascending limb of the loop of Henle?
The osmolarity of the filtrate decreases in the ascending limb of the loop of Henle as solutes are reabsorbed but water is not.
p.9
Tubular Structure and Function of Nephrons
What is the correct flow of filtered fluid through the nephron?
Renal corpuscle → Proximal tubule → Loop of Henle (thin descending limb → thin ascending limb → thick ascending limb) → Distal tubule → Collecting duct → Renal pelvis → Ureter.
p.9
Tubular Structure and Function of Nephrons
Where does the ascending limb of the Loop of Henle end?
In the cortex, after ascending from the medulla.
p.9
Tubular Structure and Function of Nephrons
What is the final destination of the filtered fluid after passing through the collecting duct?
Renal pelvis, then to the ureter.
p.28
Reabsorption and Secretion Processes in the Nephron
How are permeable solutes reabsorbed in the nephron?
Permeable solutes are reabsorbed by diffusion.
p.22
Glomerular Filtration and Influencing Factors
What is the average GFR in ml/min and L/day?
Approximately 125 ml/min or 180 L/day.
p.18
Glomerular Filtration and Influencing Factors
What is the role of the basal lamina in glomerular filtration?
The basal lamina acts as a filtration barrier between the glomerular capillary endothelium and the epithelium of Bowman's capsule.
p.4
Vascular Elements of the Kidney
Where do the renal veins carry blood from the kidneys?
To the inferior vena cava.
p.14
Tubular Structure and Function of Nephrons
What is the role of the Loop of Henle in the nephron?
It plays a crucial role in concentrating urine and reabsorbing water and salts.
p.31
Reabsorption and Secretion Processes in the Nephron
How is the concentration gradient of urea established in the proximal tubule?
Na+ and other solutes are reabsorbed from the proximal tubule, making the interstitial fluid more concentrated than the filtrate. Water follows the osmotic gradient and moves from the lumen across the epithelium by osmosis, entering the interstitial area. This increases the concentration of urea in the filtrate, creating a concentration gradient.
p.11
Glomerular Filtration and Influencing Factors
What is the function of the glomerulus in the urinary system?
The glomerulus is responsible for the bulk flow of protein-free plasma from the glomerular capillaries into the Bowman’s capsule.
p.11
Nephrons as Functional Units of the Kidney
What are the basic renal exchange processes?
The basic renal exchange processes are glomerular filtration, reabsorption, secretion, and excretion.
p.11
Tubular Structure and Function of Nephrons
What is the function of the distal tubule in the nephron?
The distal tubule is involved in the selective reabsorption and secretion of ions to maintain pH and electrolyte balance.
p.12
Nephrons as Functional Units of the Kidney
What is the function of Bowman's capsule in the nephron?
Bowman's capsule encases the glomerulus and collects the filtrate that is produced during glomerular filtration.
p.27
Tubular Structure and Function of Nephrons
What is the Loop of Henle and its function?
The Loop of Henle is a section of the nephron that concentrates urine and reabsorbs water and salts.
p.1
Regulation of Plasma Volume and Blood Pressure
What direct effect does plasma volume have on the body?
It exerts a direct effect on blood pressure.
p.13
Reabsorption and Secretion Processes in the Nephron
What is reabsorption in the context of the urinary system?
The selective transport of molecules from the lumen of renal tubules back into the blood.
p.34
Reabsorption and Secretion Processes in the Nephron
What is the renal threshold?
The plasma concentration at which solute first appears in the excretion (urine).
p.15
Reabsorption and Secretion Processes in the Nephron
What are the three main processes that determine urinary excretion of solutes?
Filtration, reabsorption, and secretion.
p.10
Vascular Elements of the Kidney
What is the juxtaglomerular apparatus?
The site where the initial portion of the distal tubule contacts the afferent and efferent arterioles of the nephron.
p.7
Vascular Elements of the Kidney
What is the sequence of blood flow through the vascular elements of the kidney?
Renal artery -> smaller arteries -> Arterioles in the cortex -> Portal system -> Renal capillaries -> Interlobular vein -> Renal vein
p.26
Glomerular Filtration and Influencing Factors
What happens to GFR and renal blood flow when sympathetic activity increases?
GFR and renal blood flow decrease due to vasoconstriction of the arterioles.
p.29
Reabsorption and Secretion Processes in the Nephron
What happens to sodium (Na+) at the basolateral side of the proximal tubule cell?
Na+ is actively pumped out by the Na+-K+-ATPase.
p.17
Glomerular Filtration and Influencing Factors
Where does the remaining four-fifths of plasma, along with plasma proteins and blood cells, flow after glomerular filtration?
Into peritubular capillaries.
p.6
Nephrons as Functional Units of the Kidney
What are juxtamedullary nephrons?
Nephrons that dip down into the medulla, making up 20% of the nephrons.
p.9
Tubular Structure and Function of Nephrons
What are the main components of the renal corpuscle?
Glomerulus and Bowman's capsule.
p.20
Glomerular Filtration and Influencing Factors
What causes colloid osmotic pressure (π) in the glomerular capillaries?
The presence of plasma proteins in the glomerular capillaries.
p.20
Glomerular Filtration and Influencing Factors
What is the hydrostatic pressure of fluid in Bowman's capsule (P fluid) and how does it influence fluid movement?
P fluid is about 15 mm Hg and it favors fluid moving back into the glomerular capillaries.
p.37
Excretion and Urine Output Variability
What factors influence urine output?
Urine output is highly variable, depending on the state of the body.
p.21
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the urinary system?
The afferent arteriole supplies blood to the glomerulus.
p.21
Tubular Structure and Function of Nephrons
What is Bowman's capsule?
Bowman's capsule is a structure surrounding the glomerulus that collects the filtrate from the blood.
p.14
Excretion and Urine Output Variability
What is the role of the collecting duct in the nephron?
It is involved in the excretion process, where urine is transported to the bladder and external environment.
p.12
Glomerular Filtration and Influencing Factors
What is the function of the glomerulus in the urinary system?
The glomerulus is responsible for the filtration of blood to form urine.
p.12
Tubular Structure and Function of Nephrons
What is the role of the Loop of Henle in the nephron?
The Loop of Henle is involved in the concentration of urine by reabsorbing water and salts.
p.11
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the nephron?
The afferent arteriole supplies blood to the glomerulus for filtration.
p.25
Tubular Structure and Function of Nephrons
What is the function of the distal tubule?
It is involved in the reabsorption and secretion of various substances.
p.27
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule in the nephron?
The proximal tubule is primarily responsible for the reabsorption of water, ions, and nutrients from the filtrate back into the blood.
p.13
Nephrons as Functional Units of the Kidney
What is Bowman's capsule?
A structure that encases the glomerulus and collects the filtrate from the blood.
p.35
Tubular Structure and Function of Nephrons
What is the function of the Loop of Henle?
To create a concentration gradient in the medulla of the kidney.
p.35
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule?
To reabsorb nutrients, ions, and water from the filtrate.
p.5
Nephrons as Functional Units of the Kidney
What are nephrons?
Nephrons are the functional units of the kidney responsible for filtering blood and forming urine.
p.28
Reabsorption and Secretion Processes in the Nephron
How is Na+ reabsorbed in the nephron?
Na+ is reabsorbed by active transport.
p.30
Reabsorption and Secretion Processes in the Nephron
What is the function of Na+-K+-ATPase in the proximal tubule cell?
Na+-K+-ATPase pumps Na+ out of the cell, maintaining the electrochemical gradient.
p.20
Glomerular Filtration and Influencing Factors
What are the three pressures that influence glomerular filtration?
Hydrostatic pressure of blood (P H), colloid osmotic pressure (π), and hydrostatic pressure of fluid in the Bowman's capsule (P fluid).
p.22
Glomerular Filtration and Influencing Factors
What are the two main factors that influence GFR?
Net filtration pressure and filtration coefficient.
p.36
Reabsorption and Secretion Processes in the Nephron
What is reabsorption in the urinary system?
Reabsorption is the process by which the kidneys reclaim water and essential solutes from the filtrate back into the bloodstream.
p.28
Reabsorption and Secretion Processes in the Nephron
What does the paracellular pathway involve in the nephron?
Substances passing through the junction between two adjacent cells.
p.14
Excretion and Urine Output Variability
What is the function of the urinary system?
To eliminate waste materials from the body in the form of urine.
p.18
Tubular Structure and Function of Nephrons
What is the proximal tubule's role in the nephron?
The proximal tubule reabsorbs nutrients, water, and ions from the filtrate.
p.21
Glomerular Filtration and Influencing Factors
How is the net filtration pressure in the glomerulus calculated?
Net filtration pressure is calculated as P_H - π (p) - P_fluid.
p.21
Glomerular Filtration and Influencing Factors
What is the hydrostatic pressure (P_H) in the glomerulus?
The hydrostatic pressure (P_H) in the glomerulus is 55 mm Hg.
p.12
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule in the nephron?
The proximal tubule reabsorbs nutrients, water, and ions from the filtrate back into the blood.
p.12
Vascular Elements of the Kidney
What is the role of the peritubular capillaries in the nephron?
The peritubular capillaries surround the tubules and are involved in the reabsorption and secretion of substances between the blood and the tubular fluid.
p.27
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the kidney?
The afferent arteriole supplies blood to the glomerulus for filtration.
p.27
Vascular Elements of the Kidney
What are peritubular capillaries and their function?
Peritubular capillaries surround the nephron tubules and are involved in the reabsorption and secretion of substances between the blood and the tubular fluid.
p.13
Tubular Structure and Function of Nephrons
What is the function of the collecting duct in the urinary system?
To collect urine from the nephrons and transport it to the bladder.
p.14
Reabsorption and Secretion Processes in the Nephron
What are the basic renal exchange processes in the urinary system?
Glomerular filtration, reabsorption, secretion, and excretion.
p.37
Tubular Structure and Function of Nephrons
What is the function of the Loop of Henle?
The Loop of Henle is involved in the reabsorption process, moving substances from the lumen back to the blood.
p.36
Reabsorption and Secretion Processes in the Nephron
What is the significance of the collecting duct in the urinary system?
The collecting duct is significant for the final concentration of urine and the regulation of water reabsorption under the influence of antidiuretic hormone (ADH).
p.18
Vascular Elements of the Kidney
What is the function of the efferent arteriole in the nephron?
The efferent arteriole carries blood away from the glomerulus after filtration.
p.14
Reabsorption and Secretion Processes in the Nephron
What is the function of the distal tubule in the nephron?
It is involved in the reabsorption and secretion processes.
p.14
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the nephron?
It supplies blood to the glomerulus for filtration.
p.14
Vascular Elements of the Kidney
What is the role of peritubular capillaries in the nephron?
They are involved in the reabsorption and secretion processes.
p.12
Vascular Elements of the Kidney
What is the function of the efferent arteriole in the nephron?
The efferent arteriole carries blood away from the glomerulus after filtration.
p.12
Tubular Structure and Function of Nephrons
What is the role of the distal tubule in the nephron?
The distal tubule is involved in the selective reabsorption and secretion of ions to regulate blood pH and electrolyte balance.
p.1
Plasma Ion Balance and Kidney Function
How do the kidneys regulate plasma ion balance?
By keeping the concentration of key ions within a normal physiological range, balancing dietary intake with urinary loss.
p.27
Reabsorption and Secretion Processes in the Nephron
Where does the majority of solute reabsorption occur in the nephron?
The majority of solute reabsorption occurs in the proximal tubule.
p.13
Glomerular Filtration and Influencing Factors
What is the glomerulus?
A network of capillaries in the nephron where blood filtration begins.
p.13
Excretion and Urine Output Variability
Where does the filtrate go after leaving the renal tubules?
To the renal vein and then to the bladder and external environment.
p.35
Reabsorption and Secretion Processes in the Nephron
Which ions are secreted by the nephron?
Potassium (K+) and Hydrogen (H+).
p.14
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule in the nephron?
It is involved in reabsorption, where substances move from the lumen back into the blood.
p.4
Vascular Elements of the Kidney
Why is a high blood flow rate critical for renal function?
Because it ensures the kidneys can effectively filter blood and maintain homeostasis.
p.21
Glomerular Filtration and Influencing Factors
What does π (p) represent in the context of glomerular filtration?
π (p) represents the colloid osmotic pressure gradient due to proteins in plasma but not in Bowman's capsule.
p.14
Vascular Elements of the Kidney
What is the function of the efferent arteriole in the nephron?
It carries blood away from the glomerulus after filtration.
p.12
Vascular Elements of the Kidney
What is the role of the afferent arteriole in the nephron?
The afferent arteriole supplies blood to the glomerulus for filtration.
p.11
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule in the nephron?
The proximal tubule is involved in the reabsorption of water, ions, and nutrients from the filtrate back into the blood.
p.11
Vascular Elements of the Kidney
What is the role of the efferent arteriole in the nephron?
The efferent arteriole carries blood away from the glomerulus after filtration.
p.27
Vascular Elements of the Kidney
What is the role of the efferent arteriole in the nephron?
The efferent arteriole carries blood away from the glomerulus after filtration.
p.1
Osmolarity Control in the Urinary System
How is the regulation of osmolarity achieved in the urinary system?
By tightly controlling the rate of water reabsorption in relation to solute concentration.
p.13
Reabsorption and Secretion Processes in the Nephron
Where do secreted molecules in the urinary system come from?
From the plasma of the peritubular capillaries.
p.35
Reabsorption and Secretion Processes in the Nephron
Why is the secretion of K+ and H+ important?
It is important in the homeostatic regulation of these ions.
p.35
Vascular Elements of the Kidney
What are peritubular capillaries?
Capillaries that surround the tubules of the nephron and are involved in reabsorption and secretion.
p.2
Plasma Ion Balance and Kidney Function
Why is it important to keep plasma pH within a narrow range?
To maintain proper physiological function and homeostasis.
p.18
Tubular Structure and Function of Nephrons
What is the distal tubule's role in the nephron?
The distal tubule further adjusts the composition of the filtrate through reabsorption and secretion.
p.14
Nephrons as Functional Units of the Kidney
What is the function of Bowman's capsule in the nephron?
It encases the glomerulus and collects the filtrate from the blood.
p.25
Glomerular Filtration and Influencing Factors
What is the glomerulus?
A network of capillaries involved in the filtration of blood.
p.25
Tubular Structure and Function of Nephrons
What is the macula densa?
A group of cells that detect NaCl concentration in the distal tubule.
p.27
Glomerular Filtration and Influencing Factors
What is the glomerulus and its primary function?
The glomerulus is a network of capillaries that performs the first step of filtering blood to form urine.
p.25
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule?
It reabsorbs nutrients, water, and electrolytes from the filtrate.
p.13
Tubular Structure and Function of Nephrons
What is the role of the distal tubule in the nephron?
To further modify the filtrate through reabsorption and secretion before it enters the collecting duct.
p.13
Tubular Structure and Function of Nephrons
What is the function of the proximal tubule in the nephron?
To reabsorb nutrients, ions, and water from the filtrate back into the blood.
p.35
Reabsorption and Secretion Processes in the Nephron
What does secretion in the nephron depend on?
Membrane transport system.
p.35
Vascular Elements of the Kidney
What is the role of the efferent arteriole in the nephron?
To carry blood away from the glomerulus.
p.35
Kidney Anatomy and Structure
What is Bowman's capsule?
A structure that encases the glomerulus and collects the filtrate from the blood.
p.21
Glomerular Filtration and Influencing Factors
What does P_H represent in the context of glomerular filtration?
P_H represents the hydrostatic pressure (blood pressure) in the glomerulus.
p.2
Excretion and Urine Output Variability
What types of wastes are excreted by the urinary system?
Metabolic wastes such as creatinine, urea, and uric acid, as well as foreign substances like drugs.
p.21
Glomerular Filtration and Influencing Factors
What does P_fluid represent in the context of glomerular filtration?
P_fluid represents the fluid pressure created by fluid in Bowman's capsule.
p.21
Glomerular Filtration and Influencing Factors
What is the net filtration pressure in the glomerulus?
The net filtration pressure in the glomerulus is 10 mm Hg.
p.21
Glomerular Filtration and Influencing Factors
What is the colloid osmotic pressure (π) in the glomerulus?
The colloid osmotic pressure (π) in the glomerulus is 30 mm Hg.
p.25
Vascular Elements of the Kidney
What role do granular cells play in the nephron?
They release renin, which regulates blood pressure.
p.12
Excretion and Urine Output Variability
What is the final destination of urine after it leaves the collecting duct?
To the bladder and external environment.
p.13
Reabsorption and Secretion Processes in the Nephron
What is secretion in the context of the urinary system?
The selective transport of molecules from the peritubular fluid to the lumen of renal tubules.
p.27
Reabsorption and Secretion Processes in the Nephron
What percentage of the filtrate is reabsorbed into the blood?
More than 99% of the filtrate is reabsorbed into the blood.
p.13
Tubular Structure and Function of Nephrons
What is the Loop of Henle and its function?
A section of the nephron that creates a concentration gradient in the medulla of the kidney, aiding in water reabsorption.
p.35
Reabsorption and Secretion Processes in the Nephron
What is secretion in the urinary system?
The transfer of molecules from extracellular fluid into the lumen of the nephron.
p.35
Glomerular Filtration and Influencing Factors
What is the glomerulus?
A network of capillaries involved in the filtration of blood.
p.11
Glomerular Filtration and Influencing Factors
What is the role of the Bowman’s capsule in the nephron?
The Bowman’s capsule collects the filtrate from the glomerulus.
p.25
Vascular Elements of the Kidney
What is the function of the efferent arteriole in the nephron?
It carries blood away from the glomerulus.
p.11
Vascular Elements of the Kidney
What is the function of the peritubular capillaries in the nephron?
The peritubular capillaries surround the tubules and are involved in the reabsorption and secretion processes.
p.25
Tubular Structure and Function of Nephrons
What is the role of the collecting duct?
It collects urine from the nephrons and transports it to the renal pelvis.
p.25
Tubular Structure and Function of Nephrons
What is the Loop of Henle?
A section of the nephron that concentrates urine and reabsorbs water and salts.
p.27
Glomerular Filtration and Influencing Factors
What is Bowman’s capsule and its role in the nephron?
Bowman’s capsule encases the glomerulus and collects the filtrate that is produced during the filtration of blood.
p.13
Vascular Elements of the Kidney
What are peritubular capillaries?
Capillaries that surround the renal tubules and are involved in reabsorption and secretion.
p.25
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the nephron?
It carries blood to the glomerulus.
p.27
Tubular Structure and Function of Nephrons
What is the primary function of the collecting duct in the urinary system?
The collecting duct is responsible for transporting urine from the nephrons to the bladder.
p.13
Glomerular Filtration and Influencing Factors
What is glomerular filtration?
The process of filtering blood to form a filtrate in the renal tubules.
p.13
Vascular Elements of the Kidney
What is the function of the afferent arteriole in the kidney?
To supply blood to the glomerulus for filtration.
p.35
Tubular Structure and Function of Nephrons
What is the function of the collecting duct in the nephron?
To transport urine from the distal tubule to the bladder and external environment.
p.11
Tubular Structure and Function of Nephrons
What is the role of the collecting duct in the urinary system?
The collecting duct collects urine from the nephrons and transports it to the bladder.
p.27
Tubular Structure and Function of Nephrons
What is the role of the distal tubule in the nephron?
The distal tubule is involved in the reabsorption of water and solutes, and the secretion of ions and waste products.
p.13
Reabsorption and Secretion Processes in the Nephron
What are the basic renal exchange processes in the urinary system?
Glomerular filtration, reabsorption, secretion, and excretion.
p.1
Plasma Ion Balance and Kidney Function
Which key ions are regulated by the kidneys?
Sodium (Na+), potassium (K+), and calcium (Ca2+).
p.35
Reabsorption and Secretion Processes in the Nephron
What is the result of secretion in the nephron?
An increase in the quantity of solute excreted in the urine.
p.25
Kidney Anatomy and Structure
What is Bowman’s capsule?
A structure that encases the glomerulus and collects the filtrate.
p.25
Glomerular Filtration and Influencing Factors
What happens when NaCl delivery past the macula densa increases?
Macula densa cells send a paracrine message to the afferent arteriole, causing it to constrict.
p.27
Reabsorption and Secretion Processes in the Nephron
Where does a smaller amount of reabsorption occur in the nephron?
A smaller amount of reabsorption occurs in the distal segment of the nephron.
p.25
Glomerular Filtration and Influencing Factors
How can GFR (180 L/day) stay constant over a wide range of arterial blood pressure (80-180 mm Hg)?
Through the tubuloglomerular response, where increased NaCl delivery past the macula densa leads to afferent arteriole constriction, increasing resistance and decreasing GFR.
p.13
Vascular Elements of the Kidney
What is the function of the efferent arteriole in the kidney?
To carry blood away from the glomerulus after filtration.
p.35
Vascular Elements of the Kidney
What is the role of the afferent arteriole in the nephron?
To supply blood to the glomerulus.
