LAB [U1] - Renal Functions Flashcards
What is the functional unit of the kidney?
Nephron
What percentage of nephrons are cortical?
85%
What structure serves as a nonselective filter in the kidney?
Glomerulus
Which arteriole carries blood into the nephron?
Afferent arteriole
What is the name of the hormone system regulating blood flow in the glomerulus?
Renin-Angiotensin-Aldosterone System (RAAS)
What is the term for the plasma concentration at which active transport stops?
Renal Threshold
Where is water reabsorbed via osmosis in the nephron?
Descending Loop of Henle
What renal function involves the elimination of waste products not filtered by the glomerulus?
Tubular Secretion
What is the earliest clearance test developed for assessing renal function?
Urea Clearance Test
What formula is used to calculate Creatinine Clearance?
C = UV / P
What is the most sensitive indicator of a decrease in glomerular filtration rate (GFR)?
Beta 2-Microglobulin
What test measures the ability of tubules to reabsorb essential salts and water?
Tubular Reabsorption Test
Which test uses P-aminohippuric acid (PAH) to assess renal blood flow?
Tubular Secretion and Renal Blood Flow Test
What instrument measures osmolality by detecting freezing point depression?
Freezing-Point Osmometer
What is the average total renal blood flow in mL/min?
1200 mL/min
What type of transport moves glucose and amino acids in the Proximal Convoluted Tubule?
Active Transport
Which nephron type is involved in concentrating urine?
Juxtamedullary nephron
What is the plasma concentration level of glucose that typically defines renal threshold?
160-180 mg/dL
What is the primary disadvantage of the Inulin Clearance Test?
Requires constant infusion
What term describes a result of zero in free water clearance tests?
No effect
What structure regulates blood flow within the glomerulus?
Juxtaglomerular Apparatus
What ion is actively transported in the ascending loop of Henle?
Sodium (Na⁺)
What substance is secreted by the adrenal cortex to regulate sodium reabsorption?
Aldosterone
What enzyme converts renin to angiotensin I?
angiotensinogen
What substance is reabsorbed in exchange for sodium in the distal tubule?
Potassium (K⁺)
What is the normal range for urine osmolality?
275–900 mOsm/kg
What process is responsible for removing hydrogen ions to maintain blood pH?
Tubular Secretion
What condition is indicated by a GFR <60 mL/min/1.73 m² for three months or longer?
Chronic Kidney Disease (CKD)
What waste product is derived from muscle metabolism?
Creatinine
Which organ releases erythropoietin in response to hypoxia?
Kidney
What term describes the ability of the kidney to maintain a constant GFR despite changes in blood pressure?
Autoregulation
What is the primary driving force for glomerular filtration?
Hydrostatic Pressure
What is the term for substances that are not reabsorbed and appear in urine?
Excreted Substances
What nephron segment reabsorbs most filtered water and electrolytes?
Proximal Convoluted Tubule
What part of the nephron concentrates urine by creating a medullary gradient?
Loop of Henle
What hormone increases water reabsorption in the collecting ducts?
Antidiuretic Hormone (ADH)
What is the term for substances actively transported into the tubular fluid?
Secreted Substances
What is the primary component of the glomerular filtration barrier?
Basement Membrane
What molecule is freely filtered but neither secreted nor reabsorbed, making it ideal for GFR testing?
Inulin
What plasma protein level reflects glomerular damage if elevated in urine?
Albumin
What hormone is secreted in response to high blood calcium levels?
Calcitonin
What condition results from the inability to concentrate or dilute urine?
Isosthenuria
What urinary test measures concentrating ability by comparing urine to plasma osmolality?
Water Deprivation Test
What molecule acts as an indicator of effective renal plasma flow?
Para-aminohippuric Acid (PAH)
What is the normal renal threshold for glucose?
160–180 mg/dL
What is the term for urine output of less than 400 mL/day?
Oliguria
What type of clearance test assesses GFR using an endogenous substance?
Creatinine Clearance Test
What is the normal range for serum creatinine in males?
0.6–1.2 mg/dL
What blood test measures nitrogen from urea to assess renal function?
Blood Urea Nitrogen (BUN)
What substance measures the ability of the kidney to excrete hydrogen ions?
Ammonium
What is the name of the capillary network surrounding the loop of Henle?
Vasa Recta
What instrument is used to measure specific gravity?
Refractometer
What hormone is released by the heart to counteract high blood pressure?
Atrial Natriuretic Peptide (ANP)
What process removes excess potassium in the distal tubule?
Tubular Secretion
What structure in the nephron is responsible for sensing sodium concentration?
Macula Densa
What is the main function of the proximal tubule?
Reabsorption
What term refers to the kidneys’ ability to excrete concentrated urine during dehydration?
Concentrating Ability
What protein in urine is an early marker for kidney damage in diabetes?
Microalbumin
What condition is defined as inflammation of the glomeruli?
Glomerulonephritis
What is the principal nitrogenous waste product excreted in urine?
Urea
What is the term for substances reabsorbed by passive transport in the nephron?
Water
What structure collects urine from the collecting ducts?
Renal Pelvis
What is the term for the volume of plasma cleared of a substance per unit of time?
Clearance
What is the name of the test that evaluates tubular concentrating ability using urine osmolality?
Fishberg Concentration Test
What nephron structure filters blood to form the initial filtrate?
Glomerulus
What protein helps maintain oncotic pressure in the glomerulus?
Albumin
What process returns essential nutrients and water from filtrate to the blood?
Reabsorption
What is the normal range for blood pH?
7.35–7.45
What hormone regulates water balance by increasing permeability of the collecting ducts?
Antidiuretic Hormone (ADH)
What kidney function test uses radioactive isotopes to measure renal plasma flow?
Renogram
What part of the nephron is impermeable to water?
Ascending Loop of Henle
What condition results from excessive loss of bicarbonate?
Metabolic Acidosis
What enzyme converts angiotensin I to angiotensin II?
Angiotensin-Converting Enzyme (ACE)
What is the average daily urine output in adults?
1200–1500 mL/day
What is the major site of urea reabsorption in the nephron?
Collecting Duct
What hormone is responsible for calcium reabsorption in the kidney?
Parathyroid Hormone (PTH)
What test evaluates renal blood flow by measuring the excretion of para-aminohippuric acid?
PAH Clearance Test
What is the primary site of secretion of drugs and toxins in the nephron?
Proximal Tubule
What structure carries blood away from the glomerulus?
Efferent Arteriole
What is the term for a test that measures the ability of the kidney to remove solutes from plasma?
Clearance Test
What substance is used in renal tests as a marker of glomerular filtration rate?
Creatinine
What is the name of the highly coiled structure located in the renal cortex?
Proximal Convoluted Tubule
A renal function where substances are removed from the glomerular filtrate and returned to the blood
Tubular Reabsorprtion
A procedure that is considered as the most associated test with the tubular secretion and renal blood flow
PAH Test
T/F: Free water clearance test is a test under the glomerular filtration rate (GFR Test)
False
except free water clearance test
T/F: Creatinine clearance is an example of an endogenous procedure
T
Organ where blood is filtered
Kidney
Tissue type present in the bladder
Transitional epithelial cell;oi,
Organ where urine output is stored
Bladder
Cortical/Juxtamedullary:
Concentrate urine reabsorption of water
Juxtamedullary
T/F: Bicarbonates are almost 100% reabsorbed
T
The human kidney receives __% of the total blood volume. While __% circulates in the organs.
25; 75
The function of the peritubular capillaries is:
A. Reabsorption
B. Filtration
C. Secretion
D. Both A and C
D
Fix in the Blood flow through the nephron in order:
- Efferent arteriole
- peritubular capillaries
- vasa recta
- afferent arteriole
Afferent arteriole > efferent arteriole > peritubular capillaries > vasa recta
The renin–angiotensin–aldosterone system is responsible for all of the following except:
A. Vasoconstriction of the afferent arteriole
B. Vasoconstriction of the efferent arteriole
C. Reabsorbing sodium
D. Releasing aldosterone
A
The primary chemical affected by the renin–angiotensin–aldosterone system is:
A. Chloride
B. Sodium
C. Potassium
D. Hydrogen
B
Secretion of renin is stimulated by:
A. Juxtaglomerular cells
B. Angiotensin I and II
C. Macula densa cells
D. Circulating angiotensin-converting enzyme
C
The fluid leaving the glomerulus has a specific gravity of:
A. 1.005
B. 1.010
C. 1.015
D. 1.020
B
Which of the tubules is impermeable to water?
A. Proximal convoluted tubule
B. Descending loop of Henle
C. Ascending loop of Henle
D. Distal convoluted tubule
C
What results from the smaller size of efferent arterioles and the glomerular capillaries?
clue: enhances filtration
Glomerular filtration
Active/Passive Transport:
low to high concentration
Active
Active/Passive Transport:
High to low concentration
Passive
When the plasma concentration of a substance is normally completely absorbed reaches a level that is abnormally high, the filtrate concentration exceeds the ________ of the tubules, and the substance begins appearing in the urine.
Maximal reabsorptive capacity (Tm)
Active/Passive:
Water, Urea, Sodium
Passive
Active/Passive:
Glucose, amino acids, salts
Active
Active/Passive:
Chloride
Active
Active/Passive:
Sodium
Active
Water goes through passive transport in the nephron’s parts, except in the _________
Ascending loop of Henle
Polymer of fructose
Inulin
Original reference method of clearance test in the past
Inulin Clearance Test
Most abundant organic substance in the urine
Urea
Most commonly used clearance test
Creatinine clearance test
Obsolete Tubular Reabsorption Test that compares the daytime and night time urine
Mosenthal Test
On the 16th hour in the Fishberg test, urine is more concentrated and should have a specific gravity of ______
1.025
Free Water Clearance (result interpretation):
+2
Positive (hydration)
Free Water Clearance (result interpretation):
0
Zero (No effect)
Free Water Clearance (result interpretation):
-2
Negative (dehydration)
Unilateral kidney test that uses an exogenous substance
Indigo carmine test
