Renal Flashcards
What are the 5 ways the kidneys regulate body fluids?
Regulation of plasma volume
Regulation of inorganic solutes
Regulation of osmotic balance
Regulation of of acid-base balance (pH)
Removing waste products
What are the 2 components of the kidney anatomically?
Tubular component and vascular component
What are the 4 arterial components we need to know in the nephron?
Afferent arterioles, glomerular capillaries, efferent arterioles, and peritubular capillaries
What do the afferent arterioles do?
Supply blood to the glomerulus
What do the efferent arterioles do?
Bring blood out of the glomerulus and connects to the peritubular capillaries
What are the two veins important to know in the nephron?
arcuate veins and interlobar veins
Why are glomerular capillaries leaky?
They are important for the filtration process and allow plasma to enter the bowman’s capsule
What process are peritubular capillaries for?
The reabsorption process
What is the functional unit of the kidney?
The nephron
What are the two capillary networkd associated with a nephron? And how are they connected?
Glomerulus and peritubular capillaries connected via the efferent arterioles
What are the 2 types of nephron and where is their glomeruli located?
Cortical nephron (glomeruli in the outer cortex) and Juxtamedullary nephron (glomeruli closer to the medulla)
Fill in the blank: vasa recta is referred to the specialized peritubular capillaries that are seen in ____ nephrons.
Juxtamedullary
What are the 3 processes that are important for renal function and formation of urine?
- Filtration
- Reabsorption
- Secretion
what is the calculation for urinary excretion rate?
excretion = filtration -reabsorption + secretion
What are the 3 reasons why the amount of filtration and reabsorption is so high?
- high permeability of the glomerular capillaries
- everything is freely filtered except cells and proteins
- concentration of most solutes in the plasma and within Bowman’s capsule is almost the same
What is the benefit of high filtration and reabsorption?
- The entire plasma is filtered many times each day
- waste products removed faster
What substances are excreted through filtration only?
most waste products (eg creatine and uric acid)
How are most electrolytes like sodium and chloride ions excreted?
filtration and partial reabsorption
What substances are excreted through filtration and complete reabsorption?
nutritional substances (glucose, amino acids)
When rapid clearance is needed, what excretion process is used?
filtration and secretion
For what substances does free filtration occur?
water and most solutes
what are glomerular capillaries important for?
filtration
what are peritubular capillaries are important for?
reabsorption
what are three things that the filtration rate of the glomerulus depends on?
1) hydrostatic pressure
2) colloid osmotic pressure
3) glomerular capillary filtration coefficient
what are the three layers of the glomerular filtration barrier?
1) endothelium of glomerular capillaries
2) basement membrane of the capillaries
3) epithelial cells of Bowman’s capsule
what factors mainly affect renal vascular resistance?
afferent arterioles
interlobular arterioles
efferent arterioles
how does sympathetic innervation affect vascular resistance?
increases vascular resistance
How is sodium reabsorbed into the epithelial cell at the lumen (apical) membrane from the
lumen of the tubule of the nephron?
sodium diffuses into the epithelial cell because of the electrochemical gradient
true or false: the transport maximums is the same for all nephrons
False
how is sodium reabsorbed at the basolateral membrane?
via active transport against the electrochemical gradient
What are the two main pathways in reabsorption?
through tubular epithelium into interstitial fluid and through peritubular
capillaries into the blood
what are the units of renal clearance?
mL/min
To calculate the Clearance Rate of substance X using the Excretion Rate, plasma concentration
of substance X should be determined using plasma from where?
arterial circulation
Which segment of the nephron is always highly permeable to water?
the thin descending loop of Henle
what segment in the loop of Henle has the greatest reabsorption capacity?
the thick ascending
what three hormones are involved in increasing water reabsorption?
Aldosterone
Angiotensin II
Antidiuretic hormone
Where is the site of aldosterone action and what does it help reabsorb and secrete?
Works in the collecting tubule and duct, helps with reabsorbing H2O and NaCl, and help
secrete K
where is 65% of ionized calcium reabsorbed?
proximal tubule
What proportion of filtered ionized calcium is reabsorbed in the kidney?
99%
