Compendium 7

The primary functions of the kidneys are the formation of urine and the regulation of fluid and electrolyte balance in the body.

Juxtamedullary nephrons have their renal corpuscle deep in the cortex and a long loop of Henle, while cortical nephrons have their corpuscles near the cortex with shorter loops.

The hilum is located on the medial side of the kidney, where the renal artery and nerves enter and the renal vein, ureter, and lymphatics exit.

<p>The renal corpuscle is the filtration unit of the nephron, consisting of the glomerulus and Bowman’s capsule, where blood filtration occurs.</p> Signup and view all the answers

<p>The adipose tissue provides cushioning and protection for the kidneys.</p> Signup and view all the answers

<p>Urine flows from the nephron to the papillary ducts, then to the minor calyces, major calyces, renal pelvis, and finally into the ureter.</p> Signup and view all the answers

<p>Bowman’s capsule features a visceral layer of podocytes that wrap around glomerular capillaries, enhancing the filtration process.</p> Signup and view all the answers

<p>Renal pyramids are cone-shaped structures in the inner medulla that contain nephrons and are involved in urine collection and transport.</p> Signup and view all the answers

<p>Fenestrae serve as small windows in the glomerular capillaries, facilitating the filtration of blood components into the nephron.</p> Signup and view all the answers

<p>The renal tubules consist of the proximal convoluted tubule, loop of Henle, and distal convoluted tubule, each involved in the process of filtration and reabsorption.</p> Signup and view all the answers

<p>The proximal convoluted tubule actively reabsorbs essential ions like Na+, K+, and Cl- back into the blood.</p> Signup and view all the answers

<p>The thick parts are made of simple cuboidal epithelium, while the thin parts consist of simple squamous epithelium.</p> Signup and view all the answers

<p>The pressure in the bladder compresses the ureters, preventing urine backflow.</p> Signup and view all the answers

<p>The renal arteries branch off the abdominal aorta, while the renal veins drain into the inferior vena cava.</p> Signup and view all the answers

<p>The trigone is a unique histological area that serves as a functional zone for urine entry and exit.</p> Signup and view all the answers

<p>Peristalsis is a smooth muscle contraction that propels urine from the renal pelvis down the ureters to the bladder.</p> Signup and view all the answers

<p>The ureters are lined with transitional epithelium, which can change shape to accommodate varying volumes of urine.</p> Signup and view all the answers

<p>The collecting duct consolidates urine from several distal convoluted tubules and plays a role in reabsorption and concentration of urine.</p> Signup and view all the answers

<p>Pressure forces the urine through the lumen of the nephron, facilitating its movement.</p> Signup and view all the answers

<p>Sympathetic stimulation decreases the frequency of urine movement through the ureters.</p> Signup and view all the answers

<p>The micturition reflex is triggered when stretch receptors in a full bladder send signals to the central nervous system, resulting in urination.</p> Signup and view all the answers

<p>The composition can vary in concentration and includes substances like urea, uric acid, and electrolytes based on the body’s hydration and metabolic state.</p> Signup and view all the answers

<p>The trigone area of the bladder helps prevent the backflow of urine into the ureters.</p> Signup and view all the answers

<p>The thin segments consist of simple squamous epithelium and are highly permeable to water, allowing some solutes to diffuse through.</p> Signup and view all the answers

<p>ADH increases the permeability of the tubule wall to water, leading to greater water reabsorption and more concentrated urine.</p> Signup and view all the answers

<p>The proximal convoluted tubule actively transports Na+ out of the cell, facilitating the reabsorption of most solutes through symport with Na+.</p> Signup and view all the answers

<p>Tubular secretion involves the movement of non-filtered substances, such as toxins and drugs, into the nephron for excretion, primarily in the distal convoluted tubule.</p> Signup and view all the answers

<p>The filtrate is reduced by approximately 15% through reabsorption of water and ions during its passage through the Loop of Henle.</p> Signup and view all the answers

<p>Symport is a mechanism where one substance, like Na+, is used to drive the transport of another substance, such as glucose, into the nephron cell.</p> Signup and view all the answers

<p>Diuretics, such as alcohol or caffeine, inhibit water reabsorption, leading to increased urine production and less concentrated urine.</p> Signup and view all the answers

<p>Ammonia, a toxic by-product of protein metabolism, is secreted into the nephron to be excreted, helping to eliminate harmful substances from the body.</p> Signup and view all the answers

<p>Substances in the Loop of Henle can move through both active and passive transport mechanisms, allowing for the reabsorption of water and ions.</p> Signup and view all the answers

<p>Peritubular capillaries are small blood vessels that surround the nephron, facilitating the exchange of substances between the nephron and the bloodstream.</p> Signup and view all the answers

<p>The three main processes are filtration, tubular reabsorption, and tubular secretion.</p> Signup and view all the answers

<p>The filtrate consists of water, glucose, fructose, amino acids, urea, ions like sodium and potassium, and creatine, but not blood cells or large proteins.</p> Signup and view all the answers

<p>The juxtaglomerular apparatus regulates filtrate formation and blood pressure by secreting the enzyme renin.</p> Signup and view all the answers

<p>Approximately 99% of the filtrate is reabsorbed back into the blood.</p> Signup and view all the answers

<p>Tubular reabsorption happens as good substances move from the nephron tubules into the interstitial fluid and then into the peritubular capillaries.</p> Signup and view all the answers

<p>The glomerular filtration rate (GFR) is the amount of filtrate produced per minute, averaging about 125 ml/min or 180 L/day.</p> Signup and view all the answers

<p>Substances like hydrogen ions, potassium ions, and certain toxins are primarily secreted into the nephron filtrate.</p> Signup and view all the answers

<p>The proximal convoluted tubule has simple cuboidal cells with microvilli that increase the surface area for reabsorption.</p> Signup and view all the answers

<p>Filtration pressure, driven by blood pressure, forces fluid from the glomerular capillaries across the filtration membrane into the Bowman's capsule.</p> Signup and view all the answers

<p>Main solutes include water, glucose, amino acids, sodium, potassium, calcium, and chloride.</p> Signup and view all the answers

<p>The renal capsule surrounds each kidney, providing protection and structural support.</p> Signup and view all the answers

<p>The nephron is the primary functional unit responsible for the filtration of blood.</p> Signup and view all the answers

<p>The loop of Henle creates a concentration gradient in the medulla, facilitating water reabsorption and concentrating urine.</p> Signup and view all the answers

<p>The renal pelvis is a funnel-shaped chamber that collects urine from the major calyces and channels it into the ureter.</p> Signup and view all the answers

<p>Juxtamedullary nephrons have longer loops of Henle which extend deeper into the medulla, allowing for enhanced concentration of urine.</p> Signup and view all the answers

<p>Podocytes have foot-like extensions that form filtration slits, preventing large molecules from entering the filtrate.</p> Signup and view all the answers

<p>Renal columns are extensions of cortical tissue that separate renal pyramids and provide structure to the kidney.</p> Signup and view all the answers

<p>The renal fascia is a thin layer of connective tissue that anchors the kidneys to the abdominal wall.</p> Signup and view all the answers

<p>The proximal convoluted tubule has a simple cuboidal epithelium with many microvilli and numerous mitochondria, increasing its surface area and energy for active transport.</p> Signup and view all the answers

<p>The distal convoluted tubule has very few microvilli compared to the proximal convoluted tubule.</p> Signup and view all the answers

<p>H+, K+, and penicillin are actively secreted into the nephron.</p> Signup and view all the answers

<p>The collecting duct's primary function is to concentrate urine by reabsorbing water, thus regulating urine volume and concentration.</p> Signup and view all the answers

<p>Parasympathetic stimulation increases the frequency of urine movement.</p> Signup and view all the answers

<p>The thick parts are lined with simple cuboidal epithelium, whereas the thin parts are composed of simple squamous epithelium, facilitating osmosis and diffusion.</p> Signup and view all the answers

<p>Urine is composed of approximately 95% water.</p> Signup and view all the answers

<p>The micturition reflex is initiated by stretch receptors in a full bladder.</p> Signup and view all the answers

<p>Transitional epithelium allows for expansion and contraction of the ureters as urine passes through them.</p> Signup and view all the answers

<p>The trigone prevents backflow of urine from the bladder into the ureters.</p> Signup and view all the answers

<p>The efferent arteriole drains blood from the glomerulus and branches into peritubular capillaries, which surround the nephron for reabsorption.</p> Signup and view all the answers

<p>Peristalsis of smooth muscle in the ureters propels urine from the renal pelvis to the urinary bladder.</p> Signup and view all the answers

<p>The trigone is a unique histological area that maintains the stability of ureteral entry points and is key in preventing backflow during bladder contraction.</p> Signup and view all the answers

<p>The renal arteries carry oxygenated blood from the abdominal aorta to the kidneys, while the renal veins transport deoxygenated blood back to the inferior vena cava.</p> Signup and view all the answers

<p>Filtration slits between podocyte foot processes allow selective passage of small molecules while retaining larger ones like proteins and cells.</p> Signup and view all the answers

<p>Na+ is actively transported across the basal surface which creates a low concentration inside the cell, allowing Na+ to move in through the apical surface.</p> Signup and view all the answers

<p>ADH increases the permeability of the tubule wall to water, leading to more water reabsorption and concentrated urine.</p> Signup and view all the answers

<p>Symport allows glucose to enter the nephron cell by 'piggybacking' on Na+ moving down its concentration gradient.</p> Signup and view all the answers

<p>The Loop of Henle facilitates the reabsorption of water and ions, reducing the filtrate volume by approximately 15%.</p> Signup and view all the answers

<p>Tubular secretion is the movement of non-filtered substances into the nephron for excretion, primarily occurring in the distal convoluted tubule.</p> Signup and view all the answers

<p>Diuretics like alcohol or coffee increase urine production by inhibiting water reabsorption in the renal tubules.</p> Signup and view all the answers

<p>The thin segments are lined with simple squamous epithelium, making them highly permeable to water and allowing some solute diffusion.</p> Signup and view all the answers

<p>Ammonia, a toxic by-product of protein metabolism, is secreted into the nephron for excretion to maintain body homeostasis.</p> Signup and view all the answers

<p>Ions in the Loop of Henle move through both active transport mechanisms and passive diffusion depending on concentration gradients.</p> Signup and view all the answers

<p>Urine composition is influenced by reabsorption and secretion processes, resulting in variable concentrations of water, ions, and waste products.</p> Signup and view all the answers

<p>The three processes are filtration, tubular reabsorption, and tubular secretion.</p> Signup and view all the answers

<p>Filtrate is the fluid that passes through the filtration membrane and contains water and small molecules, while urine is the final product that is excreted, containing waste and excess substances.</p> Signup and view all the answers

<p>The juxtaglomerular apparatus regulates filtrate formation and blood pressure by secreting the enzyme renin.</p> Signup and view all the answers

<p>GFR indicates the amount of filtrate produced each minute, which is approximately 125ml/min or 180L/day, essential for assessing kidney function.</p> Signup and view all the answers

<p>Main substances include water, glucose, amino acids, sodium, potassium, calcium, and bicarbonate.</p> Signup and view all the answers

<p>Filtration pressure, driven by blood pressure, forces fluid from the glomerular capillaries through the filtration membrane into Bowman's capsule.</p> Signup and view all the answers

<p>Peritubular capillaries allow for reabsorption of water and solutes from the renal tubules back into the bloodstream.</p> Signup and view all the answers

<p>Approximately 99% of the initial filtrate is reabsorbed back into the blood.</p> Signup and view all the answers

<p>Active transport moves substances against their concentration gradient using energy, while passive transport allows substances to move along their gradient without energy expenditure.</p> Signup and view all the answers

<p>The renal fraction is the proportion of total cardiac output that passes through the kidneys, varying from 12-30% in healthy resting humans.</p> Signup and view all the answers