Term
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Definition
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Term
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Definition
| temporary storage reservoir for urine |
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Term
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Definition
| Transport urine from the kidneys to the bladder |
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Term
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Definition
| Transports urine out of the body |
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Term
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Definition
Removal of toxins& wastes
Blood volume regulation
Gluconeogenesis during prolonged fasting
Renin(blood pressure & kidney function)
Erythropoietin(RBC production)
Activation of Vit D |
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Term
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Definition
| Structural and functional units that form urine |
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Term
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Definition
| a tuft of capillaries, part of the nephron |
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Term
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Definition
| begins as cup-shaped glomerular (Bowman's) capsule surrounding the glomerulus |
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Term
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Definition
| Glomerulus and its glomerular capsule, part of the nephron |
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Term
| Fenestrated glomerular endothelium |
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Definition
| Tissue of the nephron, fenestrated means it has pores |
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Term
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Definition
| Has parietal layer, visceral layer. Visceral layer made of podocytes and filtration slits |
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Term
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Definition
| Have little extensions that come off them that end in foot processes or pedicles. |
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Term
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Definition
| Space between the pedicles |
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Term
| Proximal convoluted tubule (PCT) |
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Definition
| part of the renal tubule, made of cuboidal cells with dense microvilli and large mitochondria. The microvilli serve to increase surface area |
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Term
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Definition
| With ascending (thick) and descending (thin) limbs |
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Term
| Distal convoluted tubule (DCT) |
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Definition
| Cuboidal cells with very few microvilli, function in secretion, not really reabsorption |
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Term
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Definition
| Receive filtrate from many nephrons, fuse together to deliver urine into minor calyces. Intercalated cells and principal cells |
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Term
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Definition
| make up 85% of nephrons. Have short loops of Henle and glomerulus further from the corticomedullary junction |
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Term
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Definition
| Long loops of Henle deeply invade the medulla |
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Term
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Definition
| Glomerulus, peritubular capillaries, vasa recta |
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Term
| Juxtaglomerular Apparatus (JGA) |
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Definition
Modified ascending loop of Henle and afferent arteriole.
Granular cells as mechanoreceptors to sense blood pressure
Macula densa as chemoreceptors to sense NaCl content
Extraglomerular mesangial cells connected by gap jctns |
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Term
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Definition
| Between blood and capsular space, allows passage of water and solute smaller than most plasma proteins. Consists of fenestrated endothelium; visceral membrane of glomerular capsule; gel-like basement membrane |
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Term
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Definition
| Blood plasma minus proteins. |
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Term
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Definition
| Made up from less than 1% of total filtrate and contains metabolic wastes and unneeded substances |
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Term
| Three major renal processes |
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Definition
Glomerular filtration
Tubular reabsorption
Tubular secretion |
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Term
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Definition
Passive mechanical process driven by hydrostatic pressure.
The glomerulus is a very efficient filter |
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Term
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Definition
The pressure responsible for filtrate formation. Determined by Glomerular hydrostatic pressure.
Opposed by colloid osmotic pressure of glomerular blood and capsular hydrostatic pressure |
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Term
| Glomerular Filtration Rate (GFR) |
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Definition
| Volume of filtrate formed per minute by the kidneys. Governed by total surface area available for filtration, filtration membrane permeability and NFP |
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Term
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Definition
| Maintains a nearly constant GFR. Two types are myogenic mechanism and tubuloglomerular feedback mechanism |
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Term
| Intrinsic Controls: Myogenic Mechanism |
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Definition
increased BP leads to constriction of afferent arterioles
decreased BP leads to dilation of afferent arterioles |
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Term
| Intrinsic Controls: TUbuloglomerular Feedback mechanism |
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Definition
| Flow-dependent mechanism directed by the macula densa cells. If GFR increases, filtrate flow increases in tubule and macula densa cells respond to increased NaCl by releasing vasoconstricting chemical |
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Term
| Extrinsic Controls: Sympathetic Nervous System |
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Definition
Under normal conditions renal blood vessels are dilated
Under stress, norepinephrine is released by the SNS and epinephrine is released by the adrenal medulla |
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Term
| Extrinsic controls: Renin-Angiotensin Mechanism |
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Definition
| Triggered when the granular cells of the JGA release renin |
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Term
| Effects of Angiotensin II |
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Definition
Constricts arteriolar smooth muscle, MAP rises
Stimulates the reabsorption of Na+
Stimulates hypothalamus to release ADH and activates thirst center
Increases fluid reabsorption
Decreases surface area available for filtration |
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Term
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Definition
Selective transepithelial process
Transcellular and Paracellular routes |
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Term
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Definition
1. Transport across laminal membrane
2. Diffusion through the cytosol
3. Transport across the basolateral membrane
4. Movement through the interstitial fluid and into capillary |
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Term
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Definition
| Movement through leaky tight junctions particularly in the PCT |
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Term
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Definition
| Na+ most abundant cation in filtrate. Primary active transport out of the tubule cell . Passes in through the luminal membrane by secondary active transport or facilitated diffusion mechanisms |
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Term
| Reabsorption of Nutrients, Water, and Ions |
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Definition
| Na+ reabsorption provides the energy and the means for reabsorbing other substances. Water is reabsorbed by osmosis, aided by aquaporins |
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Term
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Definition
1. At the basolateral membrane, Na+ is pumped into the interstitial space
2. Downhill Na+ entry at luminal membrane
3. Reabsorption of organic nutrients and certain ions by cotransport at the luminal membrane
4. Reabsorption of water by osmosis
5. Lipid-soluble substances diffuse by transcellular route
6. Cl-, K+ and urea diffuse by paracellular route |
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Term
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Definition
| Site of most reabsorption |
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Term
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Definition
| Site of most reabsorption |
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Term
| Loop of Henle Reabsorption |
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Definition
Descending: H20
Ascending: Na+, K+, Cl- |
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Term
| DCT and collecting duct reabsorption |
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Definition
hormonally regulated
Ca2+ (PTH), water (ADH), Na+(aldosterone and ANP) |
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Term
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Definition
Targets collecting ducts and DCT
Promotes Synthesis of luminal Na+ and K+ channels
Promotes synthesis of basolateral Na+ K+ ATPases |
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Term
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Definition
Reabsorption in reverse. Solutes move from peritubular capillaries or tubule cells into filtrate
Controls blood pH by altering amounts of H+ or HCO3- in urine |
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Term
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Definition
Regulates Urine Concentration and volume.
Number of solute particles in 1 kg of H20
Reflects ability to cause osmosis |
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Term
| Osmolality of body fluids |
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Definition
Expressed in milliosmols.
Kidneys maintain osmolality of plasma at 300 mOsm, using countercurrent mechanisms |
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Term
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Definition
| Occurs when fluid flows in opposite directions in two adjacent segments of the same tube. Establish and maintain an osmotic gradient from renal cortex through the medulla |
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Term
| Countercurrent multiplier |
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Definition
1. The long loops of Henle of the justamedullary nephrons create the medullary osmotic gradient
2. The vasa recta preserve the medullary gradient while removing reabsorbed water and solutes |
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Term
| Formation of Dilute Urine |
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Definition
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Term
| Formation of Concentrated Urine |
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Definition
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Term
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Definition
| Chemicals that enhance urinary output like osmotic diuretics, ADH inhibitors, and substances that inhibit Na+ reabsorption and obligatory H20 Reabsorption |
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Term
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Definition
| Volume of plasma cleared of a particular substance in a given time. Tests used to determine GFR, detect glomerular damage, follow the progress of renal disease |
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Term
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Definition
RC=UV/P
RC- renal clearance
U-concentration of the substance in urine
V- flow rate of urine formation
P- concentration of the same substance in plasma |
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Term
| Layers of the bladder wall |
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Definition
1. Transitional epithelial mucosa
2. Thick detrusor muscle (3 layers of smooth muscle)
3. Fibrous adventitia |
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Term
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Definition
1. Prostatic urethra (within prostate gland)
2. Membranous urethra (passes through the urogenital diaphragm)
3. Spongy urethra (passes through penis & opens via external urethral orifice |
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Term
| Micturition= 3 simultaneous events |
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Definition
1. Contraction of detrusor muscle by ANS
2. Opening of internal urethral sphincter by ANS
3. Opening of external urethral sphincter by somatic nervous system |
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Term
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Definition
1. Pontine storage center inhibits micturition
2. Pontine micturition center promotes micturition |
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Term
| Neural control of micturition |
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Definition
1. Stretch receptors
2. Signals from parasympathetic fibers in pelvic nerve
3. Efferent signals excite detrusor muscle
4. Efferent signals relax internal urethral sphincter.
5. For voluntary control, pons receives signals from stretch receptors
6. If it is timely to pee, pons relaxes internal urethral sphincter
7. If untimely, pons keeps external sphincter contracted
8. If timely, signals from pons cease and external sphincter relaxes. |
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