Term
| principal of tubular reabsorption and secretion |
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Definition
| volume of fluid entering the PCT is 99% too much so we need to get it back to the blood stream. |
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Term
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Definition
| return of 99% of the water & solutes back to the blood stream. Epithelial cells along the renal tubules carry out reabsoprtion; most of this is done in the PCT. |
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Term
| solutes that get reabsorpted |
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Definition
- glucose
- amino acids
- sodium ions
- potassium ions
- calcium ions
- bicarbonate ions
- phosphates ions
- small plasma protiens are reabsorbed by pinocytosis
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Term
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Definition
| happens at the same time reabsorption happens; transfer of materials from the blood and tubular cells into the tubular fluid. |
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Term
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Definition
- hydrogen ions
- potassium
- amonia
- creatine
- drugs
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Term
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Definition
- secretion of hydrogen ion: controlling PH
- secreton of substnaces that are waste products of the body. body cells will eventually secrete their substanaces into the blood and thats how they get into the urine
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Term
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Definition
substances being reabsorpted from the fluid can take 2 different pathways to get to the peritubular pathways.
- paracellular reabsorption
- transcellular reabsorption
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Term
| paracellular reabsortpion |
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Definition
| substances move between adjacent cells. Passive process. |
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Term
| transcellular reabsorption |
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Definition
| more common. Can be both active and passive. Substances move from the fluid into the cells then into the paratubular capillaries. |
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Term
| transprot mechanism details |
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Definition
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· solutes are moved out or into the tubular fluid in only 1 directions.
· Reabsorption of sodium drives the reabsortption of most of our substances being reabsorpted in water.
· Sodium moves out of the cell and into the interstitial fluid by sodium potassium pumps. This requires atp.
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Term
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Definition
| pumping of substances across a membrane by the hydrolysis of atp. |
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Term
| secondary active transport |
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Definition
| energy stored in an ions electrical chemical gradient drives another substance across the membrane. Typically one substance moves down its electrical gradient while the other substance moves against. |
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Term
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Definition
| are membrane proteins that move 2 or more substances in the same direction across the membrane. Typically sodium symporters. |
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Term
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Definition
| membrane protein moves 2 or more substances in opposite directions across the membrane. |
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Term
| obligatory water reabsorption |
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Definition
solute reabsorption drives water reabsorption. Water moves by osmosis. 90% of water reabsorption occurs with the reabsorption of sodium, chlorine, and glucose. |
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Term
| faculatative water reabsortpoion |
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Definition
| last 10% of water reabsorpted is controlled by ant-diuretic hormone in the collecting duct. ADH is inhibited by alcohol. |
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Term
| reabsorption and secretion in PCT |
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Definition
| Largest amount of solutes and water reabsorption occurs here |
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Term
| percentages of reabsorption in PCT |
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Definition
- 100% of glucose and amino acid
- 65% of water
- 65% of sodium and potassium
- most of the reabsorption is done by sodium symporters & antiporters
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Term
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Definition
- NA+ Symporters
- NA+ -glucose symporters
- Na+/H+ antiporters
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Term
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Definition
| glucose and amino acids will move across |
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Term
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Definition
| 2 sodium ions and 1 glucose molecule move from tubular fluid into the cell. |
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Term
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Definition
| one sodium ion moves down its concentration granient and one hydrogen ion is secreted back into the fluid against its concentration granient. |
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Term
| solute reabsorption in PCT promotes? |
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Definition
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Term
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Definition
| that is a waste product from the break down of amino acids is removed in the proximal convoluted tubule and will be a waste product in the urine |
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Term
| reabsorption precentages in the loop of henle |
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Definition
- 15% of the water
- 30% of sodium and postassium
- variable amounts of calcium and magnesium
- reabsorption of water by osmosis is not automatically coupled to the reabsorption of solutes
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Term
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Definition
| membrane proteins reabsorb 1 sodium, 1 potassium, and 2 chloride ions from the fluid into the cells. |
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Term
| reabsorption percentages in the early DCT |
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Definition
- 10% of water
- 5% of sodium
- 5% of chloride(done by sodium chloride symporters)
- site where parathyroid hormone stimulates the reabsorption of calcium
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Term
| reabsorption and secretion in late DCT & Collecting duct |
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Definition
when fluid reaches here 90-95% of the solutes and water have been returned
- principal cells- reabsorb sodium and secrete potassium
- intercollated cells reabsorb potassiuma nd bicaronateion and secrete hydrogen ions
- adh acts on principal cells
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Term
| hormones involoved in tubular reabsorption and tubular secretion |
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Definition
- renin angiotensisn aldosterone system
- angiotensin 2
- antidiuretic hormone(adh)
- atrial natiuretic peptide(ANP)
- parathyroid hormone
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Term
| Renin-angiotensin-aldosterone system |
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Definition
| when blood volume or blood pressure decreases juxtaglomerular cells secrete rennin, rennin is ultimately converted to angiotensis 2, |
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Term
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Definition
| is the active hormone that decreases glomerular filtration rate by vasoconstricting the afferent arterial. Angiotensis 2 also enhances the reabsoprtion of sodium, chloride and water in the PCT(proximal convoluted tubule) agiotensis2 also stimulates the release of aldosterone which stimulates the reabsorption |
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Term
| Antidiuretic Hormone (ADH) |
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Definition
| released by the posterior pituitary and regulates facultated water reabsoprtion |
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Term
| Atrial natiuretic peptide (ANP) |
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Definition
| inhibits the reabsorbtion of sodium and water. The water then goes into urine. |
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Term
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Definition
| stimulates cells in the distal convulted tubule to reabsorb calcium. This will decrease blood pressure and increase urine production. |
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