Renal Function Flashcards
Kidneys are about the size of a _________ and measures around __________
fist; 10-12 cm
Specific location of the kidney
between T12 to L3 (12th Thoracic vertebrae & 3rd Lumbar vertebrae)
3 Macroscopic Anatomy of the Kidney
Renal Cortex
Renal Medulla
Renal Pelvis
it is the outermost layer of the kidney and contains blood vessels connected to nephrons
Renal Cortex
it is the innermost layer of the kidney and contains 8-12 renal pyramids, which contain 1 million nephrons
Renal Medulla
the central region of the kidney;
location of renal sinuses; and
it is where urine is collected continuing to the ureter
Renal Pelvis
Functional unit of the kidney
Nephron
Glomerulus and Convoluted tubules are in the
Renal cortex
Cluster of capillaries
Glomerulus
A single layer of epithelial cells
Bowman’s capsule
Proximal tubule, Loop of Henle, Distal tubule and collecting duct are located in the
Renal Medulla
2 types of Nephron
Cortical Nephron & Juxtamedullary Nephron
85% ;
SHORT nephron loop;
Glomerulus FURTHER from the cortex-medulla junction;
Supplies PERITUBULAR CAPILLARIES
Cortical Nephron
15%;
LONG nephron loop;
Glomerulus CLOSER from the cortex-medulla junction;
Supplies VASA RECTA
Juxtamedullary Nephron
surrounds the proximal and distal convoluted tubules
Peritubular capillaries
Function of Peritubular capillaries
Absorbance
meshwork of capillary system;
surrounds the Loop of Henle
Vasa Recta
Function of Vasa Recta
Concentrating or Diluting Urine
6 Function of Kidneys
1 Urine Formation
2 Fluid and Electrolyte balance
3 Regulation of acid-base balance
4 Excretion of the waste products of protein metabolism
5 Excretion of drugs and toxins
6 Secretion of hormones
What 4 hormones does the kidney secrete?
Renin
Erythropoietin
1,25-Dihydroxy vitamin D3
Prostaglandins
Which of the 4 hormones help control our blood pressure and indirectly helps maintain level of Na and K?
Renin
Which of the 4 hormones stimulate red blood cell production?
Erythropoietin
Which of the 4 hormones helps on absorption of Ca (Calcium)?
1,25-Dihydroxy vitamin D3
Which of the 4 hormones regulate renal blood flow?
Prostaglandins
Summarized and generalized order for the kidneys to maintain balance
Basic Renal Process
Renal Blood Flow per minute
1200-1500 mL per minute
15 process of the Renal blood flow path:
Aorta
Renal Artery
Segmental Artery
Interlobar Artery
Arcuate Artery
Cortical Radiate Artery
Afferent Arteriole
Glomerulus (Capillaries)
Efferent Arteriole
Peritubular capillaries (Vasa Recta)
Cortical Radiate Vein
Arcuate Vein
Interlobar vein
Renal Vein
Interior Vena Cava
4 Basic Renal Process
1 Renal Blood Flow
2 Glomerular Filtration
3 Tubular Reabsorption
4 Tubular Secretion
Volume of blood filtered per minute
130-150 mL/min
Why is the glomerulus the best site for filtration?
- High Pressure due to the presence of 2 arterioles
- Semi-permeable - molecular size of less than 66,000 Daltons
- Negatively-charged basement membrane - repelling substances carrying negative charges
Substances that CAN pass through the glomerulus
Water, Electrolytes, Glucose, Amino acids, Urea, Creatinine
Substances that CANNOT pass through the glomerulus
Plasma proteins, Cellular elements, Protein-bound molecules (lipids), Albumin, Bilirubin
Happens 90% in the proximal convoluted tubule
Tubular reabsorption
Happens when substances from TUBULES to PERITUBULAR CAPILLARIES or VASA RECTA and
Tubular reabsorption
75% being reabsorb back
Sodium, water and chloride
100% being reabsorbed back
Glucose -since you can’t find sugar in the urine.
4 Movements in reabsorption
Osmosis, Diffusion, Passive and Active Movement
Exceeding concentration of substance in the blood in which the kidneys begin to remove it to the urine
Renal Threshold
Active transport substances
Glucose, Amino acids, Salts, Chloride, Sodium
Passive transport substances
Water, Urea, Sodium
What disease is making too much aldosterone and increase of sodium level
Conn syndrome
What disease is not producing enough aldosterone?
Addison’s Disease
Increased antidiuretic hormone (ADH), more water being absorbed.
Syndrome of Inappropriate Antidiuretic Hormone Secretion
Decreased antidiuretic hormone, decrease water being reabsorbed.
Diabetes Insipidus
Movement of substance from Peritubular capillaries to the Tubular Lumen
Tubular secretion
2 major functions of Tubular secretion
- Eliminating waste products not filtered by the glomerulus
- Regulating the acid-base balance in the body through the secretion of hydrogen ions
3 Renal Function Tests:
- Glomerular Filtration Tests (GFTs)
- Tubular Reabsorption Tests
- Tubular Secretion Tests and Renal Blood Flow Tests
Example of a GFT
Clearance Tests
Standard test used to measure the filtering capacity of the glomeruli
Clearance Tests
Measures the rate at which the kidneys are able to remove a filterable substance from the blood
Clearance Tests
8 Examples of the Clearance Tests
- Urea clearance test
- Creatinine clearance test
- Inulin clearance
- Cystatin C
- Beta-2-Microglobulin
- Beta Trace Protein
- Tryptophan glycoconjugate
- NGAL (Nitrogen Gelatinase Associated Lipocalin)
a type of clearance test that is the gold standard but requires intravenous infusion, is expensive and time consuming
Inulin Clearance
a type of clearance test that is available in the body;
is an inhibitor of cysteine proteinase;
not affected by sex, age and muscle mass;
very difficult to measure and is expensive
Cysteine C
a type of a clearance test in which when present in urine, it means a sign of kidney failure
Cysteine C
a type of clearance test in which protein is expressed by neutrophil
NGAL
Immediately rise within 2-6 hours if there is an acute kidney injury
NGAL
The first function to be affected when a patient has renal diseases.
Tubular Reabsorption Tests
Example of a Tubular Reabsorption test
Concentration Tests
Determine the ability of tubules to reabsorb the essential salts and water that have been non-selectively filtered by the glomerulus
Concentration Tests
Determine the ability of tubules to reabsorb the essential salts and water that have been non-selectively filtered by the glomerulus
Concentration Tests
4 Examples of Concentration Tests
- Osmolality and Osmolarity
- Free Water Clearance
- Fishberg Test
- Mosenthal Test
a type of concentration test that measures the concentration of analytes in the urine
Osmolality and Osmolarity
a type of concentration test that measures the concentration of analytes in the urine
Osmolality and Osmolarity
Number of osmose of solute in KILOGRAMS
Osmolality
Number of osmose of solute in LITER
Osmolarity
a type of concentration test that measure the amount of solute-free water being excreted in the kidney
Free water clearance
a type of concentration test that is 24 hour water deprivation
Fishberg Test
a type of concentration test that is day vs night
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 Test & Renal Blood Flow tests
3 Examples of Tubular Secretion tests & Renal Blood Flow Tests
- PAH (p-aminohippuric) test
- Titratable Acidity
- Urinary Analysis
a type of tubular test that is a nontoxic substance;
not present in the body so it is being taken orally;
loosely bound to plasma protein
PAH test (p-aminohippuric) Test
a type of tubular test that measures the amount of acid present in the solution
Titratable Acidity
a type of tubular test that is “tubular acidity - titratable acidity”;
hydrogen ion present;
concentration of ammonia
Urinary Ammonia
Waste products of the blood
Urea & Creatine
The kidney must have ___________ of nephrons still functioning to survive
20-30%
