Term
| can you list the functions of the kidney |
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Definition
-production of urine
-water and salt balance
-red blood cell production
-acid-base balance
-activition of vitamin D for metabolic use
-blood pressure regulation by water and salt volume as well as renin release |
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Term
| production of urine in the kidney |
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Definition
| for excretion of metabolic and foreign waste from the body |
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Term
| water and salt balance in the kidney |
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Definition
| maintains homeostatic balance of water and salt volume in the blood and tissues |
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Term
| red blood cell production in the kidney |
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Definition
| erythropoietin is released from the kidneys under a hypoxic conditions to stimulate the marrow to make more RBC (erythropoiesis) |
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Term
| acid-base balance of blood in the kidney |
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Definition
| controls homeostatic pH by release of HCO3- |
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Term
| can you describe the two types of nephrons |
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Definition
-cortical: entire nephron is located within the cortex
-juxtamedullary: has a long loop of henle that extends into the medulla. its loop nephron is very good at water reabsorbtion |
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Term
| can you describe the portal system of the nephron |
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Definition
| the two capillary beds are the glomerulus and the peritubular capillaries, which are seperated by the efferent arteriole |
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Term
| do you know the name of the peritubular capillaries of juxtamedullary nephron |
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Definition
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Term
| can you describe the three pressure forces acting within the glomerular capsule that leads to filtration |
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Definition
-hydrostatic pressure: pressure against the walls of the vessels caused by a fluid (blood) 55 mmHg
-colloidal osmotic pressure: pressure due to the protien albumin in the blood that results in osmosis into the capillary. 30 mmHg
- Capsular pressure: backpressure form bowman's capsule that force filtrate back into the glomerulus. 15 mmHg |
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Term
| can you list the various substances that will leave the blood by filtration in the glomerular capsule |
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Definition
| anything small enough to diffuse out of the capillary and past the filtration slits: includes water, sugars, amino acids, vitamins and metabolic wastes like urea, creatinine and uric acid |
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Term
| do you know the other name for the glomerular capsule |
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Definition
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Term
| do you know which special cells form the filtration slits around the glomerulus? |
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Definition
Podocytes, they inhibit large substances (large protiens and cells) from being filtered out of the blood if they make it past the blood capillary wall it self
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Term
| can you describe the primary functions of the proximal convuluted tubule |
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Definition
| tubular reabsorption of molecules the body wants to keep: glucose, amino acids, vitamins |
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Term
| can you describe Glomerular Filtration Rate (GFR) and what is its normal value in humans |
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Definition
| the amount of filtrate leaving the glomerulus per unit of time. it is usually reported as 125 mL/ min. This is also 180 L/Day |
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Term
| can you describe the mechanism for substances that move from the lumen of nephron tubule into the proximal convoluted tubule |
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Definition
| from the PCT cell molecules that are not lipid soluble are transported in by secondary actice transport with sodium. lipid soluble molecules (water, urea) use simple diffusion down their gradient into the cell |
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Term
| can you describe the mechanisms for substances that move from the proximal convoluted tubule cell into the extracellular fluid (and thus into the peritubular capillary) |
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Definition
| from the PCT cell to the capillary the molecules that are not lipid soluble use facilitative transport and the sodium is pumped by primary active transport. the lipid soluble molecules use simple diffusion |
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Term
| what is mean by transport maximum |
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Definition
| the maximum amount of substance that can be transported across a membrane due to the total number of transport proteins available |
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Term
| describe the mechanisms for water and salt control in the loop of henle? |
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Definition
| in the descending limb water diffuses from the lumen through aquaporins then into the pertubular capillaries.in the ascending limb sodium is pumped by primary active transport from the lumen into the peritubular capillaries |
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Term
| can you describe the change in sodum concentration in the loop of henle? |
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Definition
| entering the loop the concentration is 300 mOsm and the sodium is concentrated on the way down the tube. concentration at the bottom of the tube is 1200 mOsm. on the way up the ascending limb sodium is removed and thus is diluted to 100 mOsm by the time it leaves the loop |
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Term
| can you describe the function of the juxtaglomerular apparatus. what are the other cells of the juxtaglomerular apparatus |
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Definition
they contain baroreceptors to detect blood pressure in the afferent arteriole as it enters the glomerulus. renin will be released if blood pressure is low.
-macula densa cells, which contain osmoreceptors |
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Term
| do you know the function and mechanism of aldosterone in the kidney. where is aldosterone made/secreted |
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Definition
| aldosterone acts on the DCT and collecting duct by turning on genes that code for sodium/patassium ATPase pumps. the pumps are used to increase sodum reabsorption, and thus water in the blood. it is secreted from the adrenal cortex |
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Term
| do you know what hormones release is stimulated by renin from the hypothalmus (posterior pituitary) |
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Definition
| Antidiuretic hormone (ADH) this hormone turns on genes that code for aquaporins in the collecting duct this promotes increased water reabsorption |
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Term
| can you describe tubular secretion. where does it occur and can you give an example of a sustance that would be secreted |
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Definition
| it is active transport to remove substances from the blood that the body sees as foreign and pump it into the tubule lumen in the DCT. these substances are too large to come out of the blood as filtrate. antibiotics and toxins are examples |
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Term
| what is the equation for urine excretion |
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Definition
| excretion=filtration-reabsorption+ secretion |
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Term
| how much plasma is filtered daily? what percent is excreted daily |
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Definition
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Term
| what is the average value for the amount of urine produced and excreted daily |
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Definition
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Term
| what is the name for the types of chemicals thta inhibit ADH. examples |
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Definition
| antidiuretics. caffeine, hypertension/edema drugs |
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Term
| do you know what anuria is and can you examples what can cause it |
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Definition
| low urine output. anything that lowers NFP (net filtration pressure) which determines NFR, such as trauma, renal failure, nephritis, toxins. |
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