Term
| What are the three basic steps to urine formation? |
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Definition
| filtration, reabsorption, secretion |
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Term
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Definition
| - blood in the glomerulus is filtered through to the Bowman's capsule. Filtration is across a highly selective filtration membrane |
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Term
| What is the filtration membrane made of? What does it not allow the passage of? |
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Definition
| endothelium of the glomerulus and epithelium of the Bowman's capsule, it does not allow the passage of blood cells or large proteins |
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Term
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Definition
| valuable substances are reclaimed from the filtrate and returned to the general circulation via the peritubular capillaries/vasa recta |
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Term
| Where does reabsorption mostly occur? |
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Definition
| in the proximal convoluted tubule |
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Term
| What is prevented from being lost as waste? |
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Definition
| water, glucose, salt, an amino acids |
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Term
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Definition
| the movement of substances from the blood (in peritubular capillaries/vasa recta) into the filtrate in the tubular lumen |
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Term
| Where does secretion mostly occur? |
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Definition
| occurs mostly at the DISTAL convoluted tubule and the COLLECTING DUCT |
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Term
| What does secretion allow for? |
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Definition
| allows for the elimination of substances from the blood that wasn't filtered through the glomerulus |
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Term
| What three pressures affect the filtering process? |
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Definition
| glomerular capillary blood pressure, plasma colloid osmotic pressure, bowman's capsular hydrostatic pressure |
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Term
| What is Glomerular capillary blood pressure (GCBP)? |
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Definition
| fluid pressure exerted by the blood within the glomerulus, pushes fluid and solutes across the filtration membrane |
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Term
| The GCBP is pressure that filtration ( 55Hg) |
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Definition
| The GCBP is POSITIVE pressure that FAVORS filtration (+55 Hg) |
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Term
| What is Plasma Colloid Osmotic Pressure? |
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Definition
caused by large plasma proteins that are too big to pass across the filtration membrane
Presence of these proteins causes the osmotic movement of fluid toward the GLOM |
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Term
| PCOP hinders the movement of into the and exerts a pressure ( 30 mmHg) |
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Definition
| Plasma Colloid Osmotic Pressure hinders the movement of FILTRATE into the BOWMAN'S CAPSULE and exerts a NEGATIVE pressure (-30 mmHg) |
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Term
| What is Bowman's Capsular Hydrostatic pressure? |
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Definition
| caused by the turbulence of filtrate into the Bowman's capsule |
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Term
| BCHP interferes with moving into the and exerts a pressure ( 15 mmHg) |
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Definition
| Bowman's Capsular Hydrostatic Pressure interferes with FLUID moving into the BOWMAN'S CAPSULE and exerts a NEGATIVE pressure (-15 mmHg) |
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Term
Adding the pressures together yields the
, which determines the G F R |
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Definition
| Adding the pressures together yields the net filtration rate which determines the Glomerulular Filtration Rate |
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Term
GCBP + PCOP + BCHP = mmHg =
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Definition
| (+55 GCBP) + (-30 PCOP) + (-15 BCHP) = +10 mmHg = Net Filtration Pressure (NFP) |
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Term
- Which numbers of Net Filtration Pressure calculation contribute to filtration?
-which ones hinder filtration?
-As long as the value of NFP is the process of filtration is . |
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Definition
-positive ones contribute to filtration
-negative ones hinder filtration
- as long as the value of NFP is positive, the process of filtration is favored |
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Term
| The filtrate you have the urine you will have and vice verssa |
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Definition
| The MORE filtrate you have the MORE urine you will have and vice versa. |
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Term
| Any in any of the pressures will cause a corresponding in GFR and vice versa |
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Definition
| Any INCREASE in any of the pressures will cause a corresponding INCREASE in GFR and vice versa. |
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Term
| What are the two mechanisms for regulation of Glomulular Filtration Rate? |
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Definition
| Renal Autoregulation/myogenic, and tubulo-glomerular feedback mechanism |
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Term
| What happens during Renal Autoregulation of the GFR? |
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Definition
1. vascular smooth muscle reflexively contracts after it has been stretched
2. if blood is flowing through the afferent arteriole at a high rate/ high volume, the afferent arteriole will be stretched, then reflexively contract |
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Term
| What does the afferent arteriole being stretched then reflexively constrict have an effect on? |
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Definition
| Slows blood flow to the glomerulus, preventing GCBP from becoming too high, therefore preventing GFR from becoming too high |
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Term
| A in flow rate/volume in the arteriole will cause it to . |
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Definition
| A decrease in flow rate/volume in the afferent arteriole will cause it to dilute. |
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Term
| The decrease in flow rate/volume in the afferent arteriole causes.... |
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Definition
| increases blood flow to the glomerulus, preventing GCBP from becoming too low, therefore preventing GFR from becoming too low |
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Term
| What is tubulo-glomerular feedback mechanism? |
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Definition
| involves a structure in the nephron called the juxtaglomerular apparatus |
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Term
| What type of cells is the Juxtaglomerular apparatus made of? |
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Definition
vascular cells
and
tubular cells |
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Term
| What is another name for vascular cells? why? |
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Definition
| granular cells because they contain renin granules |
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Term
| How is the RENIN in the vascular cells in the juxtaglomerular apparatus used? |
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Definition
| Renin is released when the cells sense a decrease in GFR; caused presumably by a decrease in systemic blood pressure |
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Term
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Definition
- constriction of the Efferent arteriole
- posterior pituitary to release ADH
- adrenal cortex to release aldosterone |
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Term
| Constriction of the arteriole, back pressure in GLOM, GCBP and GFR |
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Definition
| Constriction of the efferent arteriole, increase back pressure in GLOM, increasing GCBP and increasing GFR |
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Term
| Angiotensin II causes posterior pituitary to release , increasing reabsorption at the level of the collecting duct and the , blood volume, BP, GCBP, and . |
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Definition
| Angiotensin II causes posterior pituitary to release ADH, increasing water reabsorption at the level of the collecting duct and the distal convoluted tubule, increasing blood volume, Blood pressure, glomerulular capillary blood pressure, and glomerulular filtration rate |
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Term
| Angiotensin II causes to release increasing reabsorption, water reabsorption at the colecting duct and distal convoluted tubule, blood volume, BP, GCBP, and GFR. |
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Definition
| Angiotensin II causes adrenal cortex to release aldosterone, increasing water reabsorption, at the collecting duct and distal convoluted tubule, increasing blood volume, blood pressure, glomerulular capillary blood pressure, glomerulular filtration rate. |
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Term
1. What is another name for tubular cells?
2. What do tubular cells do? |
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Definition
1. macula densa
2. sense the rate of NaCl flow |
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Term
| If rate of NaCl flow is high, the tubular cells release |
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Definition
| if rate of NaCl flow is high the tubular cells release endothelin |
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Term
| What happens after the release of endothelin cause by high rate of NaCl flow? |
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Definition
| afferent arteriole constricts, decreasing blood flow to the GLOM, decreasing GCBP, and decreasing GFR |
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Term
| If NaCl flow rate is low (GFR IS NEGATIVE), the tubular cells release . |
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Definition
| If rate is low (GFR IS NEGATIVE), the tubular cells release Brady Kinin |
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Term
| What happens after Brady Kinin is released due to a low rate of NaCl flow? |
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Definition
| Afferent arteriole dilates, increasing blood flow to GLOM, increasing GCBP, increasing GFR |
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Term
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Definition
| movement of valuable substances out of the filtrate within tubules and into the blood of the peritubular capillaries |
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Term
- What is Na+ reabsorption?
- Process is driven by a / . The is located on the surface of the tubule epithelial cells |
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Definition
-80% of the ATP needed by the kidneys is used for actively reabsorbing Na+
- the process is driven by a Na+/K+ ATPase pump. The pump is located on the BASOLATERAL surface of the tubule epithelial cells |
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Term
Na+ reabsorption
(picture) |
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Definition
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Term
| What role do Cl- and HCO3 play in reabsorption? |
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Definition
Cl- and HCO3 are reabsorbed following electrical gradients
- they maintain electrical neutrality in plasma and filtrate |
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Term
| What happens to the non-reabsorbed substances? |
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Definition
| there is a high concentration of non-reabsorbed substances in the urine, which are either too large to be reabsorbed or don't have the specific carrier proteins |
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Term
| What are the specific carrier proteins? |
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Definition
| urea, creatine, and uric acid |
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Term
| What are the specific TUBUlar regions of reabsorption? |
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Definition
| Proximal convoluted tube, loop of henle, distal convoluted tube, collecting duct |
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Term
| What is reabsorbed in PCT? |
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Definition
Proximal Convoluted Tube
-all glucose and amino acids
-a majority of H2O, Na+, HCO3-, Cl-, K+ |
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Term
| What is reabsorbed in Loop of Henle? |
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Definition
some Na+, Cl-, and K+ at ascending loop of henle (salts)
some H2O at descending loop of Henle |
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Term
- What does reabsorption in the distal convoluted tubule and collecting duct depend on?
- what does it target tissues for? |
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Definition
- what the body needs and circulating hormone levels
- ADH and Aldosterone |
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Term
Distal Covoluted tubule, and Collecting Duct
(picture) |
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Definition
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Term
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Definition
| movement of substances (not needed) from the blood in the peritubular capillaries and into the filtrate in the tubular lumen |
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Term
Secretion of is important in maintaining pH.
Where does secretion of this occur?
What does the secretion of this depend on? |
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Definition
Secretion of H+ is important in maintaining pH.
- it occurs at proximal convoluted tubule, distal convoluted tubule and collecting duct
- it depends on the acidity of BODY FLUIDS |
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Term
if the body fluids are:
too acidic = secretion of H+
too basic = secretion of H+ |
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Definition
too acidic = increase secretion of H+
too basic = decrease secretion of H+ |
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Term
K+
- where it is secreted from?
- what it does? |
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Definition
- active secretion in distal convoluted tubule and collecting duct
- coupled to Na+ reabsorption via the Na+/K+ ATPase pump at the basolateral surface of the tubule epithelial cells |
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Term
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Definition
coupled to Na+ reabsorption via the Na+/K+ ATPase pump at the basolateral surface of the tubule epithelial cells
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Term
| What effect does aldosterone have on K+ reabsorption? |
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Definition
Aldosterone alters the rate of K+ secretion at the same time it alters the rate of Ha+ reabsorption
INCREASE in ALDOSTERONE = INCREASE in Na+
reabsorption = increase in K+ secretion |
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