Renal Function Prt. 1 Flashcards by Kyra Catedral

KIDNEY
• Paired, bean-shaped organs found retroperitoneally in either side of the____
• About the size of a______
• Between_____

spinal column

fist (10-12cm)

T12-L3

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make up the functional tissue of the kidney

cortex & medulla

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MACROSCOPIC ANATOMY of the kidney (3)

Renal Cortex
Renal Medulla
Renal Pelvis

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• Outermost region
• Contains blood vessels which is connected to the nephrons

Renal Cortex

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Innermost region
• Contains the renal pyramid
•______ renal pyramids which contains about______ nephrons

Renal Medulla

8 - 12

1 million

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• Central region

Located in renal sinuses (cavity inside the kidney)

Where urine is being collected and is connected directing to the ureter

Renal Pelvis

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o is the functional unit of the kidney

Nephrons

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Glomerulus & Convoluted Tubules
• Found in the_______

renal cortex

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Collecting Ducts & Others
Found in the_____

medulla

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5 main parts nephron in order

Glomerulus
Proximal convoluted tubules
Loop of Henle
Distal convoluted tubules
Collecting ducts

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• Cluster or tuft of capillaries

Glomerulus

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Single layer of epithelial cells

Bowman’s Capsule

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TWO TYPES OF NEPHRON:

Cortical Nephron (85%)

Juxtamedullary Nephron (15%)

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• Very short nephron loop

Glomerulus is further away from the cortex-medulla junction

Efferent arteriole supplies peritubular capillaries

Cortical Nephron (85%)

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Capillaries that surround the PCT and DCT

Main function is more on re-absorbance.

peritubular capillaries

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Very long nephron loop

Glomerulus is closer from the cortex-medulla junction

Efferent Arteriole supplies vasa recta

Juxtamedullary Nephron (15%)

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• Capillaries that surround the Loop of Henle

• Main function is more on concentration gradient of the kidney

vasa recta

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Functions of Kidney?!

• Urine formation
• Fluid and electrolyte balance
• Regulation of acid-base balance
• Excretion of the waste products of protein metabolism
• Excretion of drugs and toxins
• Secretion of hormones

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Hormones secreted by kidney

REP1,25

Renin
Erythropoietin
1,25-Dihydroxyvitamin D3
Prostaglandin

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Helps control blood pressure & indirectlv helps maintain the level of sodium & potassium

Renin (Renin-Angiotensin-Aldosterone-System)

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• Stimulate RBC production

Ervthropoietin

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• Hormone involved in the absorption of calcium

1.25-Dihydroxyvitamin D3 (Complete name of the active vitamin D)

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(Pro-inflammatory substance)
• Help in the regulation of our renal blood flow

Prostaglandin

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BASIC RENAL PROCESS
Renal Glo Tur Tus

• Renal blood flow
• Glomerular filtration
• Tubular reabsorption
• Tubular secretion

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Renal Blood Flow mL/ minute

• 1,200-1,500 mL/min

Renal Blood Flow ARSIAC AGE PCAIRI

Aorta Renal artery Segmental artery Interlobar artery Arcuate artery Cortical radiate artery Afferent arteriole Glomerulus Efferent arteriole Peritubular capillaries or vasa recta Cortical radiate vein Arcuate vein Interlobar vein Renal vein Inferior vena cava

GLOMERULAR FILTRATION What are the factors that make the glomerulus the best site for filtration? Hi Se nega glo glo

High pressure in the glomerulus Semi-permeability of the glomerulus Negatively-charged basement membrane Glomerular Filtrate = 130-150 mL/min GLOMERULAR FILTRATION RATE

Glomerular Filtrate =

130-150 mL/min

What can pass through the glomerulus

Water Electrolytes Amino acids Glucose Urea Creatinine

What cannot pass through the glomerulus

Plasma proteins Cellular elements Protein-bound molecules

TUBULAR REABSORPTION Reabsorption occurs____% in the___ 75% of the____, ____, ____ 100% of the____

90% - PCT sodium, chloride, water glucose

TUBULAR REABSORPTION Almost all of the _____,______,_____ Variable amounts of____,_____,____ (Ca, Mg, K, HCO3)

amino acids, vitamins, proteins urea, uric acid, ions

TUBULAR REABSORPTION •_______ of uric acid, only to be secreted at the DCT • About only ____of glomerular filtrate actually leaves our body.

98-100% 1%

• Concentration of your substance in the blood above w/c the kidneys begins to remove it into the urine. • REMEMBER: If a substance's concentration exceeds the _______for tubular reabsorption, it will appear in the urine

renal threshold

renal threshold of glucose

160-180 mg/dL

Active transport

Glucose, amino acids, salts Chloride Sodium

Tubular reabsorption Glucose, amino acids, salts

Proximal convoluted tubule

Tubular reabsorption Chloride

Ascending LOH

Tubular reabsorption Sodium

Proximal and distal convoluted tubules

Tubular reabsorption Water

Proximal convoluted tubule Descending loop of Henle Collecting duct

Tubular reabsorption Urea

Proximal convoluted tubule Ascending loop of Henle

Tubular reabsorption Sodium

Ascending loop of Henle

Passive transport

Water Urea Sodium

Overproduction of aldosterone = increased sodium level

Conn Syndrome

Opposite of Conn's Syndrome -› Not producing enough aldosterone = lower Na level

Addison's Disease

• Increased ADH = more water reabsorbed

SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion)

Decreased ADH = lesser water reabsorbed

Diabetes Insipidus

Aldosterone ADH Targets?

DCT Collecting Ducts

Movement of substances from the peritubular capillary plasma to the tubular lumen

Tubular Secretion

Tubular cells secrete products of their own cellular metabolism to the filtrate in the tubular lumen

Tubular secretion

TUBULAR SECRETION Movement of substances from the _______ to ______

peritubular capillary plasma to the tubular lumen

TUBULAR SECRETION Two maior functions:

1. Eliminating waste products not filtered by the glomerulus 2. Regulating the acid-base balance in the body through the secretion of hydrogen ions.

Tubular secretion Regulating the acid-base balance in the body through the secretion of_____

hydrogen ions

Tubular secretion Eliminating waste products _____by the glomerulus

not filtered

RENAL FUNCTION TESTS

• Glomerular Filtration Tests (GFTs) • Tubular Reabsorption Tests • Tubular Secretion Tests • Renal Blood Flow Tests

WHY PERFORM RENAL FUNCTION TESTS? • These rely on the measurement of the waste products in the blood (usually______ and _____) which accumulate when the kidneys begin to fail. • Alarming once the substances that are not usually present in urine was detected

urea and creatinine

There should be ______ of the nephrons still functioning (advanced renal failure) before the concentration of these products begin to accumulate in the blood.

20%-30%

Clearance Test is for???

GLOMERULAR FILTRATION TESTS

• standard test used to ***measure the filtering capacity of the glomeruli*** • Measures the rate at which the kidneys are able to ***remove a filterable*** substance from the blood

Clearance Test

GLOMERULAR FILTRATION TESTS Clearance Test Common tests

Urea clearance test Creatinine clearance test Inulin clearance Cystatin C

GLOMERULAR FILTRATION TESTS Clearance Test Uncommon tests

• Beta-2 Microglobulin • Beta Trace Protein • Tryptophan glycoconjugate • Neutrophil Gelatinase Associated Lipocalin (NGAL)

To ensure accuracy of the test, the substance to be analyzed must: 1. Be neither______ and_____ 2. Be_____ in the urine during a possible 24-hour collection period 3. Have a consistent_____ level 4. Be______ to the_____ 5. Be available for________ (can be tested)

reabsorbed nor secreted stable plasma available, body chemical analvsis

• Regarded as the gold standard for clearance test (glomerular filtration test) Cannot be reabsorbed & secreted Requires intravenous infusion

Inulin Clearance

Clearance test • Available in the body = inhibitor of your cysteine proteinase • _____ is completely reabsorbed. • Produced by all of our nucleated cells • Not affected by age, sex, or muscle mass • Readily filtered by the glomerulus = very small size & is positively charged.

Cystatin C

is present in the urine, which gives us an early identification of a possible kidnev failure.

Cystatin C

• Protein being expressed by vour neutrophils & epithelial cells in PCT • Acute Kidney Injury makes the concentration of NGAL rises wlin 2-6 hours A verv useful early predictor of vour acute kidnev iniurv.

Neutrophil Gelatinase Associated Lipocalin (NGAL)

Concentration tests are for???

TUBULAR REABSORPTION TESTS

Determine the ***ability of the tubules to reabsorb the essential salts and water*** that have been non-selectively filtered by the glomerulus

Concentration Test

Concentration Test (4)

• Osmolality and osmolarity • Free water clearance • Fishberg Test • Mosenthal Test

Measures the amount of solute free water excreted in the kidney.

Free water clearance

24-hour water deprivation. Afterward, measurement of the specific gravity of the urine.

Fishberg Test

• In relation to checking the specific gravity • Day vs. night time of checking of specific gravity • Comparing the volume and specific gravity of your urine sample in the morning and in the evening to evaluate the concentrating ability of kidney/tubules.

Mosenthal Test

To measure the ***exact amount of blood flowing through the kidney,*** it is necessary to use a substance that is: • Completely removed from the blood (peritubular capillaries) rather than being removed when the blood reaches the glomerulus

TUBULAR SECRETION AND RENAL BLOOD FLOW TESTS

TUBULAR SECRETION AND RENAL BLOOD FLOW TESTS (3)

• PAH (P-aminohippuric) Test) • Titratable Acidity • Urinary Ammonia

Nontoxic substance (exogenous substance). Loosely bound to plasma proteins Not readily present in the body = it is taken up.

PAH (P-aminohippuric) Test

Measures the amount of acid present in a solution • Ability of your kidney to produce acidic urine.

Titratable Acidity

• Total Acidity - Titratable Acidity • Both tests can be run simultaneously. • Collect a 2-hr interval of sample (before and after) the intake of oral ammonium chloride.

Urinary Ammonia

How many percent of sodium, chloride, and water is reabsorbed in the tubules?

75%

How many percent of glucose is reabsorbed in the tubules?

100%

How many percent of amino acids, vitamins , proteins is reabsorbed in the tubules?

Almost all

How much urea, uric acid, ion are reabsorbed in the tubules?

Variable amounts

How many percent of uric acid is reabsorbed in the tubules?

98-100%

How many glomerular filtrate leaves the body?

Conn Syndrome

Increase ALDOSTERONE and SODIUM

Addison disease

decrease ALDOSTERONE and SODIUM

Syndrome Inappropriate Antidiuretic Hormone Secretion

Increase ADH and WATER

Diabetes Insipidus

Decrease ADH and WATER