RENAL FUNCTION Flashcards
The kidneys are bean shaped and are located on the posterior abdominal wall in the area known as the peritoneum.
A. True
B. False
B. False
RETROperitoneum
Functional unit of kidney and its approximate amount
Nephron (1-1.5 million)
The renal vein supplies blood to the kidney. The human kidney receives approximately 75%.
A. First statement is true, second statement is true.
B. First statement is false, second statement is true.
C. First statement is true, second statement is false.
D. First statement is false, second statement is false.
D. First statement is false, second statement is false.
- Renal ARTERY
- Receives 25%
What are the three main forces involved in glomerular filtration?
- Hydrostatic Pressure
- Glomerular Capillary Pressure
- Oncotic Pressure
This is caused by the higher protein concentration in the plasma
Oncotic pressure
This pressure is created by the varying sizes of the arterioles
Hydrostatic pressure
Net filtration pressure of the three main forces of glomerular filtration
10 mmHg
Average of hydrostatic blood pressure
55 mmHg
supplies blood individually to the glomerulus of each nephron
afferent arteriole at the vascular pole
This maintain consistency of Glomerular capillary pressure and renal blood flow within the glomerulus
Hydrostatic Pressure
Order of blood flow in the nephron
- Glomerulus
- Renal vein
- Peritubular capillaries
- Renal artery
- Afferent arteriole
- Efferent arteriole
- Vasa recta
4 - 5 - 1 - 6 - 3 - 7 - 2 (RA-AA-G-EA-PC-VR-RV)
Renal artery → Afferent arteriole → Glomerulus → Efferent arteriole → Peritubular capillaries → Vasa recta → Renal vein
Order of urine formation from the Nephron
- ALH
- Bowman’s capsule
- Collecting Ducts
- Glomerulus
- DLH
- PCT
- DCT
4 - 2 - 6 - 5 - 1 - 7 - 3 (G-BC-PCT-DLH-ALH-DCT-CD)
Glomerulus→ Bowman’s capsule → PCT → DLH→ ALH→
DCT→ Collecting Ducts
consists a coil of approximately eight capillary lobes referred to collectively as the capillary tuft.
Glomerulus
General functions of the Kidney: (6)
- Excretory function
- Regulation of water balance in the body.
- Regulation of acid-base balance
- Regulation of electrolytes
- Regulation of Blood pressure through secretion of Renin
- Stimulates Erythropoiesis through secretion of EPO
Nephron that have loops of Henle that extend deep into the medulla of the kidney. Their primary function is the concentration of urine.
Juxtamedullary nephrons
makes up approximately 85% of the total nephron. Found mainly in the cortex of the kidney and are responsible primarily for removal of waste products and reabsorption of nutrients.
Cortical Nephrons
Where is glomerulus located
Within Bowman’s capsule
Three layers of glomerulus where plasma filtrate must pass through
- Capillary wall membrane
- Basement membrane
- Visceral epithelium of Bowman’s capsule
Intertwining foot processes
Podocyte
Barriers that prohibits the filtration of large molecules:
- Fenestrations in capillary walls of glomerulus
- Podocyte
- Shield of negativity
Repels molecules with a negative charge even molecules are small enough to pass
Shield of Negativity
The macula densa maintains the glomerular blood pressure. It is found in the DCT, sensor of change in blood pressure.
A. First statement is true, second statement is true.
B. First statement is false, second statement is true.
C. First statement is true, second statement is false.
D. First statement is false, second statement is false.
B. First statement is false, second statement is true.
- The Juxtaglomerular apparatus maintains the glomerular blood pressure.
- Macula densa is found in DCT.
- Increase Blood pressure = Constriction of afferent arteriole, Dilation of efferent arteriole.
- Decrease Blood Pressure = Constriction of afferent arteriole, dilation of efferent arteriole.
A. First statement is true, second statement is true.
B. First statement is false, second statement is true.
C. First statement is true, second statement is false.
D. First statement is false, second statement is false.
C. First statement is true, second statement is false.
- Decrease BP dilates AA, and constricts EA.
System regulates the flow of blood to and within the
glomerulus
Renin-Angiotensin-Aldosterone System (RAAS)
Primary electrolyte affected when RAAS is activated:
Sodium
A small protein (molecular weight 13,359) produced at a constant rate by all nucleated cells. It is readily filtered by the glomerulus and reabsorbed and broken down by the renal tubular cells. It has potential as a marker for long-term monitoring of renal function
Cystatin C
It dissociates from human leukocyte antigens at a constant rate and is rapidly removed from the plasma by glomerular filtration. It is a better marker of reduced renal tubular function than of glomerular function
BETA-2-MICROGLOBULIN
A polymer of fructose. It is an extremely stable substance that is not reabsorbed or secreted by the tubules. It is not a normal body constituent, however, and must be infused by IV at a constant rate throughout the testing period.
Inulin
Reference method for Glomerular filtration
Inulin Clearance test
A waste product of muscle metabolism that is produced enzymatically by creatine phosphokinase from creatine, which links with ATP to produce ADP and energy.
Creatinine
Most commonly used clearance test for glomerular filtration
Creatinine clearance test
Passive reabsorption of water takes place in all parts of the nephron except the descending loop of Henle. Sodium is actively transport in all part of the nephron except in the Ascending loop of Henle.
A. First statement is true, second statement is true.
B. First statement is false, second statement is true.
C. First statement is true, second statement is false.
D. First statement is false, second statement is false.
B. First statement is false, second statement is true.
- Passive reabsorption of water takes place in all parts of the nephron except the ASCENDING loop of Henle.
the maximal rate of reabsorption of a solute by the tubular epithelium per minute (mg/min)
Maximal Tubular reabsorptive capacity
The plasma concentration at which active transport
stops is termed the renal threshold. Sodium renal threshold is 110-130 mmol/L.
A. First statement is true, second statement is true.
B. First statement is false, second statement is true.
C. First statement is true, second statement is false.
D. First statement is false, second statement is false.
A. First statement is true, second statement is true.