What do homeostatic mechanisms ensure in terms of fluid balance in health?
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They ensure that fluid outputs closely match fluid inputs and that the fluid balance is 'neutral'.
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What do homeostatic mechanisms ensure in terms of fluid balance in health?
They ensure that fluid outputs closely match fluid inputs and that the fluid balance is 'neutral'.
What is the primary function of the kidneys?
Maintaining a state of balance (steady-state).
What new tool is mentioned for observing kidney function?
The specific tool is not mentioned in the provided text.
What are the ECF and ICF in relation to osmotic equilibrium?
The ECF (extracellular fluid) and ICF (intracellular fluid) are in osmotic equilibrium.
What is the Intracellular Compartment?
The space within the cells.
What is the Interstitial Fluid (ISF) Compartment?
The space between cells, filled with interstitial fluid.
Where are the kidneys located?
The kidneys are retroperitoneal paired organs, located at T11/T12 - L3.
What percentage of the human body is water?
Approximately 60%.
What is the Intravascular Compartment (Plasma)?
The fluid compartment within blood vessels, consisting of plasma.
What percentage of cardiac output do the paired renal arteries take?
About 25%.
What are the common imaging techniques used for kidney examination?
Radiograph and CT (Computed Tomography).
What is the primary focus of Lecture 1.2?
Gross Anatomy and Imaging of the Urinary System.
What is the average weight of each kidney?
Each kidney weighs about 150 grams.
What percentage of the human body is composed of solids?
Approximately 40%.
What is Hydrostatic Pressure (P H)?
The pressure exerted by a fluid due to its weight.
What imaging technique is commonly used for staging renal cancer?
CT scans.
What is one of the posterior relations of the kidney?
Thoracolumbar fascia.
What are the main components of the urinary system?
Kidneys, ureters, urinary bladder, and urethra.
What is the primary function of the glomerulus?
The glomerulus is a highly specialized filter.
Where do the ureters pass to?
The ureters pass to the bladder (subperitoneal).
What fraction of body weight do the organs supplied by the renal arteries represent?
Less than 1/100th of body weight.
What anatomical structure is located at the transpyloric plane?
The duodenum.
What does TBW stand for?
Total Body Water.
What does Capillary Hydrostatic Pressure induce?
It induces filtration.
What substances are forced through the glomerulus?
Water, electrolytes, glucose, and amino acids.
Why are CT scans used in the context of renal cancer?
For staging the cancer.
What must the osmolarity of ECF and ICF be?
They need to have the same osmolarity.
How does the bladder empty periodically?
The bladder empties periodically via the urethra.
Where is the urinary system located within the body?
Within the abdominopelvic cavity and is retroperitoneal.
Where is water located in the human body?
Water is distributed in various compartments including intracellular fluid (inside cells) and extracellular fluid (outside cells).
What is the nephron?
The nephron is the functional unit of the kidney responsible for filtering blood and forming urine.
What is the significance of the transpyloric plane in surface markings?
It helps in identifying the position of the duodenum anteriorly.
What are the three points of constriction in the ureters?
What is the relationship of the peritoneum to the urinary bladder?
The peritoneum partially covers the urinary bladder, specifically the superior surface.
What maintains a constant filtration pressure in the glomerulus?
Regulation of the local circulation (autoregulation).
What do mechanisms controlling osmolarity ensure?
They ensure that there is enough water to dilute the total solute in the extracellular space to isotonicity.
What is the coronal anatomy of the prostate?
The coronal anatomy of the prostate refers to the cross-sectional view of the prostate gland as seen from the front, dividing the body into anterior and posterior parts.
Why is the nephron shaped the way it is?
The nephron's shape, with its various segments and loops, allows for efficient filtration, reabsorption, and secretion processes necessary for urine formation and maintaining body fluid balance.
What creates the constant pressure in the glomerular capillaries?
Constant pressure in the glomerular capillaries forces substances through the glomerulus.
What determines the ECF?
The concentration and distribution of solutes in the body.
What medical imaging technique is used for the detection of kidney stones?
CT Scan.
Which surface of the urinary bladder is covered by the peritoneum?
The superior surface.
What anatomical plane is located at the level of L1 in a coronal MRI?
The transpyloric plane.
What is the clinical significance of the points of constriction in the ureters?
These points are common sites where kidney stones can become lodged, causing pain and potential obstruction.
What is ultrafiltrate composed of?
Water, ions, and small molecules.
What are the three fluid compartments of the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, Intravascular Compartment (Plasma).
What does zonal anatomy of the prostate refer to?
Zonal anatomy of the prostate refers to the division of the prostate gland into different zones, each with distinct histological and functional characteristics.
What does ECF volume dictate?
Arterial blood pressure.
What are the three main fluid compartments of the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, and Intravascular Compartment (Plasma).
What separates the three fluid compartments of the body?
Water-permeable membranes.
What happens to nearly everything that is filtered in the kidneys?
It is reabsorbed.
Does the peritoneum completely cover the urinary bladder?
No, it only partially covers the superior surface.
How many vertebral bodies and disc spaces are typically covered in the craniocaudal (CC) length at the transpyloric plane?
3.5 vertebral bodies and disc spaces.
What is the approximate diameter of the large ureteric stone shown in the video?
Approximately 10mm.
What must be regulated to control ECF volume?
The total amount of solutes in the ECF.
Which fluid compartment contains albumin?
Intravascular Compartment (Plasma).
What is a characteristic sign of acute ureteric obstruction in a nephrogram?
A very dense nephrogram.
What is the characteristic of the vesico-ureteric junction?
It is angulated.
How does water move across semi-permeable membranes?
From areas of low osmolarity to areas of high osmolarity.
Which fluid compartment is found inside cells?
Intracellular Compartment.
What is the normal Glomerular Filtration Rate (GFR)?
120 ml/min/1.73 m².
What is the vertebral venous plexus?
A network of valveless veins known as Batson's plexus.
What percentage of Total Body Water (TBW) is Intracellular Fluid (ICF)?
66.6%
What is the perinephric fat?
An accumulation of extraperitoneal fat that completely surrounds the kidney.
What type of pressure is created by the retention of albumin in the plasma?
Colloid osmotic pressure or oncotic pressure.
What happens when extracellular fluid (ECF) osmolarity is lower than intracellular fluid (ICF) osmolarity?
The ECF is hypotonic, and water moves into cells.
What percentage of total body water (TBW) is found in adult males?
Approximately 60%.
What does a plain film conventional radiogram show in the provided image?
A calcified staghorn calculus in each kidney.
What are the three main fluid compartments in the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, Intravascular Compartment (Plasma).
How many liters of plasma will be filtered per day?
Approximately 180 liters per day.
Which fluid compartment surrounds the cells?
Interstitial Fluid (ISF) Compartment.
What percentage of Total Body Water (TBW) is Extracellular Fluid (ECF)?
33.3%
What does a delayed appearance of the pyelogram on the left side indicate?
Acute ureteric obstruction from a stone in the lower end of the left ureter.
What is a notable feature of Batson's plexus?
It consists of valveless veins.
What is the bladder trigone?
It is a triangular area on the internal surface of the bladder.
What is the main function of the Loop of Henle?
To create a gradient of increasing osmolarity in the renal medulla by counter-current multiplication.
What is hydrostatic pressure (P H)?
Hydrostatic pressure is the pressure exerted by a fluid due to its weight.
What are the different parts of the male urethra?
Preprostatic urethra, prostatic urethra, membranous (non-distensible) urethra, penile (spongy) urethra, and navicular fossa urethra.
What happens when extracellular fluid (ECF) osmolarity is higher than intracellular fluid (ICF) osmolarity?
The ECF is hypertonic, and water moves out of cells.
What percentage of total body water (TBW) is found in adult females?
Approximately 50%.
What is the renal fascia?
A layer of connective tissue that surrounds the kidney and perinephric fat.
What protein is contained in the intravascular compartment (plasma) that contributes to colloid osmotic pressure?
Albumin.
What is the total volume of plasma in the body?
Approximately 3 liters.
Which fluid compartment is found within blood vessels?
Intravascular Compartment (Plasma).
How is Total Body Water (TBW) divided between Intracellular Fluid (ICF) and Extracellular Fluid (ECF)?
2/3 Intracellular Fluid (ICF) and 1/3 Extracellular Fluid (ECF)
What is a staghorn calculus?
A large kidney stone that takes the shape of the renal pelvis and calyces.
What does the film taken 23 hours after the injection of contrast medium show?
Opacification of the obstructed collecting system down to the obstructing calculus.
What are the two limbs of the Loop of Henle?
The thin descending limb and the thick ascending limb (TAL).
Does the Interstitial Fluid (ISF) Compartment contain albumin?
No, the Interstitial Fluid (ISF) Compartment does not contain albumin.
Through what environment does the collecting duct descend?
The high osmolarity ('salty') environment of the medulla.
With which venous drainage does the vertebral venous plexus communicate?
Prostatic venous drainage.
Why is it important for the body to regulate the osmolarity of the extracellular fluid (ECF)?
To maintain an isotonic state and prevent damage.
What is the approximate percentage of total body water (TBW) in neonates?
Approximately 80%.
How does Na+ enter across the luminal membrane?
Na+ enters across the luminal membrane down its concentration gradient via various channels and transporter proteins.
What is the most likely consequence of an enlargement of the prostate?
It can obstruct the flow of urine through the prostatic urethra.
Where is the urinary tract located in relation to the peritoneum?
The urinary tract is retroperitoneal.
What are the posterior muscular relations of the kidney?
Psoas, quadratus lumborum, and transversus abdominis.
What are the two main pressures involved in Starling's Forces?
Colloid osmotic pressure (π) and hydrostatic pressure (P H).
What percentage of the body is composed of solids?
40%
Which imaging technique is used to identify a calcified staghorn calculus?
Plain film conventional radiogram.
What triggers the release of aldosterone from the adrenal glands?
Low [Na+] in the ECF (and hence low ECF volume).
What percentage of filtered glucose and amino acids are reabsorbed in normal water and electrolyte balance?
100% of filtered glucose and amino acids are reabsorbed.
What is the approximate percentage of total body water (TBW) in infants?
Approximately 70%.
What is the role of the Loop of Henle in reabsorption?
It is a further site of reabsorption of water and salts.
What creates the high osmolarity environment in the medulla?
The loop of Henle.
What drives the reabsorption of other substances such as glucose and phosphate?
Energy from Na+ movement drives the reabsorption of other substances such as glucose and phosphate.
What is the role of hydrostatic pressure (P H) in Starling's Forces?
It drives filtration of fluid out of the capillaries.
What percentage of the body is composed of Total Body Water (TBW)?
60%
What shape are the kidneys?
Bean-shaped.
What is the function of the renal fat?
To provide cushioning and protection to the kidney.
Which muscle is abbreviated as 'P' in the posterior relations of the kidney?
Psoas.
What are the internal and external urethral sphincters responsible for?
The internal urethral sphincter controls the release of urine from the bladder, while the external urethral sphincter provides voluntary control over urination.
What percentage of HCO3- is reabsorbed in normal water and electrolyte balance?
100% of HCO3- is reabsorbed.
What is the approximate percentage of total body water (TBW) in the elderly?
Approximately 45%.
What role does aldosterone play in sodium reabsorption?
Aldosterone stimulates the expression of sodium channels and sodium-potassium ATPases in the cell membranes of the principal cells of the late distal tubule and collecting duct.
What is intravenous urography (IVU)?
A medical imaging technique where a contrast medium is injected into a vein and X-ray images are taken as the medium circulates through the blood to reach the kidneys.
What is the role of colloid osmotic pressure (π) in Starling's Forces?
It drives absorption of fluid into the capillaries.
How many lobes does the prostate have?
The prostate has five lobes.
What type of cells line the tubules of the nephron?
Simple epithelial cells.
What hormone regulates the permeability of the collecting duct to water?
Vasopressin (also known as anti-diuretic hormone or ADH).
What are the three main fluid compartments of the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, and Intravascular Compartment (Plasma).
Between which vertebrae are the kidneys located?
Between L3 and T11/T12.
What is the role of Na+-K+-ATPases in sodium transport?
Na+-K+-ATPases actively extrude Na+ across the basolateral membrane while K+ enters the cell against their respective concentration gradients.
Which muscle is abbreviated as 'QL' in the posterior relations of the kidney?
Quadratus lumborum.
What muscle is associated with the external urethral sphincter?
Levator ani.
What percentage of filtered water is recovered in normal water and electrolyte balance?
Over 99% of filtered water is recovered.
What are the three main fluid compartments of the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, Intravascular Compartment (Plasma).
What percentage of the human body is composed of solids?
Approximately 40%.
What is the normal pH range of extracellular fluid?
7.35 - 7.45
How many liters of ECF do the glomeruli filter per day?
Approximately 180 liters/day.
Where does aldosterone stimulate sodium reabsorption?
In the principal cells of the late distal tubule and collecting duct.
What is the net flow of fluid in the venous capillaries according to Starling's Forces?
Absorption.
What imaging technique is used to view the axial anatomy of the abdomen?
MRI (Magnetic Resonance Imaging).
What are the three main fluid compartments in the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, and Intravascular Compartment (Plasma).
How is the contrast medium administered in intravenous urography?
It is injected into a vein, usually in the arm.
Which fluid compartment contains albumin?
Intravascular Compartment (Plasma).
What characteristic do all epithelial cells in the nephron have?
They are polarized.
What does vasopressin (ADH) determine in the kidneys?
Urine concentration.
What are the names of the five lobes of the prostate?
The five lobes of the prostate are the anterior lobe, posterior lobe, two lateral lobes, and the median lobe.
What is the anatomical term for the location of the kidneys?
Retroperitoneal.
How does water follow electrolytes in the nephron?
Water follows electrolytes by osmosis.
What percentage of filtered Na+ is reabsorbed in normal water and electrolyte balance?
Over 99% of filtered Na+ is reabsorbed.
Which muscle is abbreviated as 'TA' in the posterior relations of the kidney?
Transversus abdominis.
Which fluid compartment contains albumin?
Intravascular Compartment (Plasma).
What are ureter luminal narrowings?
They are points along the ureter where the lumen (interior space) is naturally constricted.
Why must the pH of extracellular fluid be maintained within the range of 7.35 - 7.45?
To prevent protein denaturation.
What is the major site of variable reabsorption of electrolytes and water in the nephron?
The distal convoluted tubule (DCT).
Where does obligatory reabsorption of substances occur in the nephron?
In the proximal tubule.
Which fluid compartment does not contain albumin?
Interstitial Fluid (ISF) Compartment.
What protein is found in the intravascular compartment and contributes to colloid osmotic pressure?
Albumin.
How does aldosterone affect ECF volume?
By allowing the reabsorption of Na+ from the tubular fluid, aldosterone helps control ECF volume.
What does 'axial' refer to in MRI imaging?
Axial refers to images taken in a horizontal plane, dividing the body into upper and lower parts.
What does intravenous urography demonstrate?
The structure of the kidneys as the contrast medium is filtered from the blood, passing through the kidneys to the ureters.
Why is the polarization of epithelial cells important?
It allows the expression of different membrane proteins on the luminal and basolateral membranes, enabling directional transport across the epithelium.
Which lobe of the prostate is located in front of the urethra?
The anterior lobe.
Where do the kidneys lie in the body?
On the posterior abdominal wall.
What is the role of hydrostatic pressure (P H) in the fluid compartments?
Hydrostatic pressure helps to move fluid out of the capillaries into the interstitial space.
What happens to substances like H+ in the process of secretion?
They are secreted, meaning we excrete more than is filtered.
How many natural narrowings are typically found in the ureter?
There are typically three natural narrowings in the ureter.
What is colloid osmotic pressure (π) primarily influenced by?
Albumin.
What is the tonicity of the fluid leaving the loop of Henle?
Hypotonic.
What largely determines plasma pH?
The concentration of the buffer hydrogen carbonate (HCO3-) in plasma.
From where do the renal arteries branch off?
The renal arteries branch off the aorta.
What percentage of the body is composed of fluids?
60%
Where does variable reabsorption of Na+ and water occur in the nephron?
In the distal tubule and collecting duct.
What are the two main pressures involved in fluid movement across capillary walls?
Colloid osmotic pressure (π) and hydrostatic pressure (P H).
Why is MRI preferred for detailed imaging of the abdomen?
MRI provides high-resolution images and better contrast of soft tissues without using ionizing radiation.
Why are a series of X-ray images taken during intravenous urography?
To capture the contrast medium as it circulates through the blood and reaches the kidneys.
What is the function of the luminal and basolateral membranes in the nephron?
They allow directional transport of substances, such as Na+, across the epithelium.
Which lobe of the prostate is located behind the urethra?
The posterior lobe.
Can albumin pass through the endothelium of the capillaries?
No, albumin cannot pass through the endothelium of the capillaries.
Which kidney is normally found slightly lower than the other?
The right kidney.
What is hydrostatic pressure (P H)?
The pressure exerted by a fluid within a closed system.
Which ions are removed from the fluid in the distal tubule?
Sodium and chloride ions.
Where do the renal arteries arise in relation to the superior mesenteric artery (SMA)?
The renal arteries arise inferiorly to the SMA.
What happens to filtered HCO3- in the kidneys?
It is quickly reabsorbed back into the peritubular capillaries.
What percentage of the body is composed of solids?
40%
What contributes to the regulation of plasma pH in the nephron?
Controlled secretion of H+ ions and variable recovery of hydrogen carbonate ions.
Which ion primarily regulates extracellular fluid (ECF) volume?
Na+ (Sodium).
Where is the first natural narrowing of the ureter located?
At the ureteropelvic junction, where the renal pelvis transitions into the ureter.
What are some key structures visible in an axial MRI of the abdomen?
Key structures include the liver, kidneys, spleen, pancreas, and major blood vessels.
What process occurs alongside reabsorption in the nephron?
Secretion of waste products from the capillaries into the tubules via the interstitial fluid (ISF).
Which lobes of the prostate are situated on either side of the urethra?
The two lateral lobes.
Which fluid compartment does not contain albumin?
Interstitial Fluid (ISF) Compartment.
What are 'Starling’s Forces'?
Forces that determine the net flow of fluid into or out of the capillaries.
Why is the right kidney normally found slightly lower than the left kidney?
Due to the presence of the liver.
What are the three main fluid compartments of the body?
Intracellular Compartment, Interstitial Fluid (ISF) Compartment, and Intravascular Compartment (Plasma).
What is secreted from the blood into the distal convoluted tubule?
H+ (hydrogen ions).
What is the position of the renal veins relative to the renal arteries?
The renal veins are anterior to the renal arteries.
What is the chemical reaction involving HCO3- and H+ in plasma?
HCO3- + H+ ↔ H2CO3 ↔ CO2 + H2O
How do the kidneys control plasma osmolarity?
By filtering and variably recovering water.
What is the principal cation in intracellular fluid?
K+ (Potassium)
Which ion is primarily found in the intracellular fluid (ICF)?
K+ (Potassium).
Where is the second natural narrowing of the ureter located?
Where the ureter crosses the pelvic brim.
How does MRI differentiate between different types of tissues in the abdomen?
MRI differentiates tissues based on their water content and the magnetic properties of hydrogen atoms in the body.
What are the two routes for transport across the tubular epithelium?
Paracellular route and transcellular route.
Which lobe of the prostate is located between the urethra and the ejaculatory ducts?
The median lobe.
What is the net flow of fluid according to 'Starling’s Forces' in the arterial capillaries?
A net flow of fluid out of the arterial capillaries (filtration).
Where do the renal veins drain into?
The renal veins drain into the inferior vena cava (IVC).
What protein is found in the intravascular compartment and contributes to colloid osmotic pressure?
Albumin.
Under the influence of which hormone can Ca2+ be reabsorbed from the distal convoluted tubule?
Parathyroid hormone (PTH).
Which muscles are associated with the positioning of the kidneys?
Psoas, Iliacus, and Quadratus Lumborum.
How do the kidneys control plasma volume?
By filtering and variably recovering sodium.
What are 'Starling’s Forces' responsible for?
Filtration and absorption of fluids across capillary walls.
Where is the third natural narrowing of the ureter located?
At the ureterovesical junction, where the ureter enters the bladder.
What does TBW stand for?
Total Body Water
What are the two main renal arteries visible in the anterior view of the left kidney?
Upper (1) and lower (2) left renal arteries.
Does the Interstitial Fluid (ISF) Compartment contain albumin?
No, it does not contain albumin.
Which renal vein is longer, and what is its path?
The left renal vein is longer and it passes under the superior mesenteric artery (SMA).
Which ion primarily regulates extracellular fluid (ECF) volume?
Na+ (Sodium).
Why can't Na+ diffuse through the plasma membrane?
Because it requires specific transport mechanisms like the Na+/K+ - ATPase.
What percentage of TBW is intracellular fluid?
66.6%
What does 'AA' stand for in the context of the left kidney vasculature?
Abdominal aorta.
What does the pelvic cavity in males contain?
The connection between urinary and reproductive tracts.
Why is the length and path of the left renal vein significant?
The left renal vein's longer length and path under the SMA can have clinical significance, such as susceptibility to compression (e.g., Nutcracker syndrome).
What role does the Na+/K+ - ATPase play in maintaining osmotic balance?
It maintains high [K+] in the ICF and high [Na+] in the ECF.
Which ion is primarily found inside cells and helps to pull water into cells?
K+ (Potassium).
What percentage of TBW is extracellular fluid?
33.3%
What does 'CT' represent in the dissection of the left renal arteries?
Celiac trunk.
How long is the male urethra compared to the female urethra?
The male urethra is approximately 18-20 cm long, which is longer than the female urethra.
How is osmotic pressure generated?
Through the inability of solutes to cross membranes.
What is the approximate osmolality of the intracellular, interstitial, and intravascular compartments?
~287 mOsm/kg.
What percentage of extracellular fluid is interstitial fluid?
75%
What are the two major glands associated with male reproduction?
The prostate and seminal vesicles.
What does 'IVC' stand for and what is its position in the dissection image?
Inferior vena cava, reflected down.
What forces are involved in the movement of fluid between compartments, according to Starling's Forces?
Filtration and Absorption.
What percentage of extracellular fluid is plasma?
25%
What does 'IPA' refer to in the context of the left kidney vasculature?
Left inferior phrenic artery.
What prevents Na+ from diffusing through the plasma membrane?
The plasma membrane (PM) itself.
What is the principal cation in extracellular fluid?
Na+ (Sodium)
What does 'LRV' stand for in the dissection of the left renal arteries?
Left renal vein.
What role does albumin play in the intravascular compartment?
Albumin pulls water into the plasma.
Does interstitial fluid contain albumin?
No
What is the 'PA' in the context of the left kidney vasculature?
Polar artery arising from the left upper renal artery.
What is the effect of Na+ on water movement in the interstitial fluid compartment?
Na+ pulls water into the ISF.
Does plasma contain albumin?
Yes
What does 'RRA' stand for in the dissection of the left renal arteries?
Right renal arteries.
What is the primary function of the ureters?
To transport urine from the kidneys to the bladder.
What type of pressure is associated with the movement of water due to albumin in the plasma?
Colloid osmotic pressure (π).
How long are the ureters?
25 – 30 cm long.
What is the major site of reabsorption from the tubular filtrate?
The proximal convoluted tubule (PCT).
What does 'SMA' represent in the context of the left kidney vasculature?
Superior mesenteric artery.
What is the diameter of the ureters?
Around 3 – 4 mm in diameter.
What percentage of sodium ions (Na+) is reabsorbed in the PCT?
65%.
With what are the ureters continuous superiorly?
The renal pelvis.
What percentage of chloride ions (Cl-) is reabsorbed in the PCT?
65%.
What is the anatomical location of the ureters?
The ureters are tubes that carry urine from the kidneys to the bladder.
What are the bony landmarks associated with the ureters?
The ureters pass anterior to the psoas major muscle and cross the pelvic brim at the bifurcation of the common iliac arteries.
What percentage of potassium ions (K+) is reabsorbed in the PCT?
65%.
How is the renal pelvis formed?
By a condensation of several minor calices.
What percentage of urea is reabsorbed in the PCT?
50%.
Where do the ureters enter the bladder?
The ureters enter the bladder at the ureterovesical junction.
Where does the renal pelvis become the ureter?
At the ureteropelvic junction.
What is the significance of the ureter's path in relation to the psoas major muscle?
The ureters pass anterior to the psoas major muscle, which is a key anatomical landmark for their location.
On which aspect of the psoas major do the ureters descend?
The medial aspect.
What percentage of phosphate (PO4 2-) is reabsorbed in the PCT?
85%.
Where are the kidneys anatomically positioned in the human body?
The kidneys are located retroperitoneally on either side of the spine, between the levels of T12 and L3 vertebrae.
At what point do the ureters cross the pelvic brim?
The ureters cross the pelvic brim at the bifurcation of the common iliac arteries.
What percentage of hydrogen carbonate (HCO3-) is reabsorbed in the PCT?
90%.
What is the relationship of the female pelvis to the uterus and rectum?
The female pelvis is anatomically related to both the uterus and the rectum.
What do the ureters cross at the pelvic brim?
The common/external iliac arteries.
What is the anatomical position of the ureters in the human body?
The ureters run from the renal pelvis of each kidney, descend along the posterior abdominal wall, and enter the bladder at its base.
What is a key advantage of conventional radiography in imaging the urinary system?
It is useful for visualizing radio-opaque stones and is relatively cheap.
What percentage of glucose and amino acids is reabsorbed in the PCT?
100%.
How long is the female urethra?
Approximately 4 cm.
Describe the anatomical position of the bladder in males and females.
In males, the bladder is located anterior to the rectum and superior to the prostate gland. In females, it is located anterior to the uterus and vagina.
What are the disadvantages of conventional radiography for imaging the urinary system?
It uses ionizing radiation, has poor resolution, and is rarely used for urinary system imaging.
How is water reabsorbed in the PCT?
By osmosis, keeping the filtrate isotonic.
Why do females have an increased risk of urinary tract infections (UTIs) compared to males?
Due to the shorter length of the female urethra.
Where is the urethra located in males and females?
In males, the urethra runs through the prostate and penis. In females, it is shorter and opens anterior to the vaginal opening.
What is an intravenous urogram (IVU) particularly useful for?
Checking the normal function of kidneys and determining the course of the ureter, as well as the presence and location of stones.
What percentage of filtrate is reabsorbed from the PCT into the peritubular capillaries?
Around 67%.
What are the main components of the gross structure of the urinary system in males?
The main components include the kidneys, ureters, bladder, and urethra, with the urethra passing through the prostate and penis.
What are the disadvantages of an intravenous urogram (IVU)?
It requires the injection of a contrast medium into a vein and multiple doses of ionizing radiation.
What substances are secreted into the PCT?
Substances like drugs, NH4+, and H+.
What are the main components of the gross structure of the urinary system in females?
The main components include the kidneys, ureters, bladder, and urethra, with the urethra being shorter and opening anterior to the vaginal opening.
What is the gold standard imaging technique for renal cancer staging?
CT (computed tomography).
What is the primary function of the urinary bladder?
To store urine until it is excreted from the body.
What are the medulla, cortex, and renal pyramids in the human kidney?
The cortex is the outer layer, the medulla is the inner region, and the renal pyramids are cone-shaped structures within the medulla.
What are the advantages of CT (computed tomography) in urinary system imaging?
It creates 3D axial slices of the body, can be used with or without contrast, and is highly sensitive and specific for imaging stones.
What type of muscle makes up the wall of the urinary bladder?
Detrusor muscle, which is a type of smooth muscle.
What is the renal blood supply?
The renal arteries supply blood to the kidneys, branching off from the abdominal aorta, and the renal veins drain blood from the kidneys into the inferior vena cava.
What are the disadvantages of CT (computed tomography) in urinary system imaging?
It involves a high dose of ionizing radiation, is more costly than X-ray, and the X-ray beam moves around the body in a circle.
What is the name of the triangular area at the base of the bladder?
Trigone.
Describe the course of the ureters in relation to the iliac vessels and reproductive organs.
The ureters cross over the iliac vessels and in males, they pass near the vas deferens, while in females, they pass near the uterine ovary.
What are the advantages of MRI (magnetic resonance imaging) in urinary system imaging?
It uses radio waves and magnets, doesn't use ionizing radiation, has excellent resolution, and is good for evaluating soft tissue.
What is the ultra-structure of the urethra and its muscle layers?
The urethra is lined with epithelial cells and surrounded by smooth muscle layers that facilitate the passage of urine.
What are the two sphincters associated with the urinary bladder?
The internal urethral sphincter and the external urethral sphincter.
What imaging technique is used to detect a stone in the right kidney?
Ultrasound.
What are the disadvantages of MRI (magnetic resonance imaging) in urinary system imaging?
It is noisy, time-consuming, expensive, and requires the patient to remain still for a prolonged amount of time.
Which part of the nervous system controls the internal urethral sphincter?
The autonomic nervous system.
What is the musculature of the bladder?
The bladder is composed of a muscular layer called the detrusor muscle, which contracts to expel urine.
What is ultrasound used for in urinary system imaging?
It is used to quickly evaluate the size and shape of the kidneys, and for imaging stones, hydronephrosis, and focal lesions.
How does a kidney stone appear on an ultrasound?
As a bright echo.
Which part of the nervous system controls the external urethral sphincter?
The somatic nervous system.
What are the advantages of ultrasound in urinary system imaging?
It uses high-frequency sound waves, provides good resolution, and is operator-dependent.
What is the acoustic shadow in an ultrasound of a kidney stone?
It is the shadow that appears behind the stone.
What type of epithelium lines the urinary bladder?
Transitional epithelium.
What is tubular reabsorption?
Tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid and returns them to the circulating blood.
What is the capacity of the average adult urinary bladder?
Approximately 400-600 milliliters.
What is tubular secretion?
Tubular secretion is the transfer of materials from peritubular capillaries to the renal tubular lumen, which helps in the removal of waste products and the regulation of blood pH.
Which part of the nephron is primarily responsible for reabsorption?
The proximal convoluted tubule (PCT) is primarily responsible for reabsorption.
What role does the loop of Henle play in urine formation?
The loop of Henle concentrates urine by reabsorbing water and salts, creating a concentration gradient in the medulla.
How does the distal convoluted tubule (DCT) contribute to urine formation?
The distal convoluted tubule (DCT) fine-tunes the reabsorption of ions and water, and is involved in the secretion of ions, acids, drugs, and toxins.
What is the function of the collecting duct in the nephron?
The collecting duct adjusts the final concentration of urine by reabsorbing water and urea, influenced by antidiuretic hormone (ADH).
What is the urinary bladder?
A subperitoneal reservoir for urine that can hold up to approximately 500 ml.
What is the significance of the peritubular capillaries in the nephron?
Peritubular capillaries surround the renal tubules and are involved in the exchange of substances between the blood and the tubular fluid, facilitating reabsorption and secretion.
How does the size, shape, and wall thickness of the urinary bladder vary?
The urinary bladder can vary greatly in size, shape, and wall thickness.
How does aldosterone affect tubular reabsorption?
Aldosterone increases sodium reabsorption and potassium secretion in the distal convoluted tubule and collecting duct, which helps regulate blood pressure and fluid balance.
Where is the urinary bladder positioned when empty?
Anteriorly in the lesser pelvis.
What is the role of antidiuretic hormone (ADH) in the nephron?
Antidiuretic hormone (ADH) increases water reabsorption in the collecting ducts, concentrating the urine and reducing urine volume.
Where does the urinary bladder extend when full?
Into the abdominal cavity.
How does water move across cell membranes?
Water can cross cell membranes freely by osmosis.
In males, what structure crosses over the ureter posterior to the urinary bladder?
The ductus deferens.
What drives the movement of water across cell membranes?
The movement of water always occurs passively and is driven by osmotic forces.
In females, what structure crosses over the ureter lateral to the cervix of the uterus?
The uterine artery.
What is osmotic concentration (osmolarity)?
Osmotic concentration (osmolarity) is the total concentration of substances that do not cross the membrane freely.
Which substances are included in osmotic concentration?
All ions (e.g., Na+, K+, Cl-) and some organic molecules (e.g., urea).
How is osmolarity measured?
Osmolarity is measured as the number of osmoles (Osm) per litre (Osm/L).
What is 1 Osm?
1 Osm is 1 mol (Avogadro's number) of any non-dissociable substance.
What is the normal osmolarity of ECF and ICF?
Approximately 287 mOsm/L.
Why does urea not contribute to osmotic pressure at equilibrium?
Because urea can cross cell membranes freely.
What is Nutcracker syndrome?
A condition where the left renal vein is compressed between the aorta and the superior mesenteric artery.
Which vein is affected in Nutcracker syndrome?
The left renal vein.
What anatomical structures compress the left renal vein in Nutcracker syndrome?
The aorta and the superior mesenteric artery.
What are common symptoms of Nutcracker syndrome?
Symptoms can include hematuria (blood in urine), flank pain, and varicocele in males.
How is Nutcracker syndrome diagnosed?
It can be diagnosed using imaging techniques such as Doppler ultrasound, CT angiography, or MRI.
What are potential treatments for Nutcracker syndrome?
Treatment options may include observation, stenting of the renal vein, or surgical intervention.
What is the outer region of the kidney called?
Renal cortex
What is the inner region of the kidney that contains the renal pyramids?
Renal medulla
What are the cone-shaped structures in the renal medulla called?
Renal pyramids
What is the tip of a renal pyramid that releases urine into the minor calyx?
Renal papilla
What are the structures that separate the renal pyramids?
Renal columns
What is the primary function of the renal arteries?
To supply blood to the kidneys.
What are the structures that collect urine from the renal papillae?
Major and minor calyces
What is the role of the afferent arterioles in the kidneys?
They carry blood to the glomeruli.
What is the funnel-shaped structure that collects urine from the major calyces?
Renal pelvis
What is the function of the glomeruli in the kidneys?
To filter blood and form urine.
What is the tube that carries urine from the renal pelvis to the bladder?
Ureter
What do the efferent arterioles do in the kidneys?
They carry blood away from the glomeruli.
What is the role of the peritubular capillaries?
To surround the renal tubules and facilitate reabsorption and secretion.
What is the vasa recta and its function?
A series of straight capillaries in the medulla that help concentrate urine.
How does blood leave the kidneys?
Through the renal veins.
What are the main fluid compartments of the body?
The main fluid compartments of the body are the intracellular fluid (ICF) and the extracellular fluid (ECF).
What is the composition of intracellular fluid (ICF)?
Intracellular fluid (ICF) is rich in potassium, magnesium, phosphate, and proteins.
What is the composition of extracellular fluid (ECF)?
Extracellular fluid (ECF) is rich in sodium, chloride, bicarbonate, and has lower concentrations of proteins compared to ICF.
What are the main components of the urinary system?
The main components of the urinary system are the kidneys, ureters, bladder, and urethra.
What is the structure of the kidney?
The kidney has an outer cortex, an inner medulla, and contains functional units called nephrons.
What is the structure of a nephron?
A nephron consists of a renal corpuscle (glomerulus and Bowman's capsule) and a renal tubule (proximal tubule, loop of Henle, distal tubule, and collecting duct).
What are the physiological roles of the kidneys?
The kidneys are responsible for the excretion of waste products, control of osmolarity, control of blood volume, and regulation of body fluid pH.
How do the kidneys control osmolarity?
The kidneys control osmolarity by regulating the concentration of solutes in the blood through selective reabsorption and secretion.
How do the kidneys contribute to the control of body fluid pH?
The kidneys regulate body fluid pH by excreting hydrogen ions and reabsorbing bicarbonate from urine.
