Lecture 16 Flashcards
- kidney
- ureter
- bladder
- urethra
- nephron
- minor calyx
- major calyx
- papilla
- renal cortex
- renal pelvis
- renal medulla
- renal pyramid
- capsule of kidney
- ureter
left side then right side
renal artery
segmental arteries
interloper arteries
arcuate arteries
interlobular arterioles
______ nephron is when it is less deep and _____ nephron is deeper
cortical nephron
juxtamedullary nephron
starts to go in from the ______ to ______and goes out the ______ in the nephron
afferent arteriole
glomerulus
efferent arteriole
left to right
glomerulus
bowman’s capsule
proximal tubule
distal tubule
loop of henle
fluid follows _____ in osmosis
solute
__________ throughout the body have different permeability to substances and fluids.
Determined by what the organ the capillaries supply need, or the function the organ supplies to the body.
Capillary beds
In the kidneys, different areas have different permeabilities.
This includes:
_________ , ________, ________
Glomerulus
Proximal and Distal Tubules
Kidney Medulla
_______________ (beginning) - water and most solutes in the blood plasma move across the _________ wall and collects in the urinary (Bowman’s) space and then flows into the renal tubule.
glomerular filtration
glomerular capillary
______________- As fluid flows through the renal tubule substances are transported out of the tubular fluid and subsequently returned to the capillary blood which surrounds the kidney tubules
Tubular reabsorption
tubular transport can either be ___________, depending upon the transported substance and particular conditions of transport
active or passive
_______________: As fluid flows through the renal tubule and collecting duct, the tubule and duct cells secrete other waste materials.
Tubular Secretion
___________: refers to the elimination via the urine, expressed as: ______________
Excretion
Filtered-Reabsorbed +Secreted
how do new assess kidney function?
As clearing substances from the blood plasma (renal clearance).
When a certain substance is found in the urine, it is said to be cleared from the blood—a process called __________
renal clearance
renal clearance equation
Cx= (Ux)( x )(V)
______________
Px
- x is the substance
- Cx is the clearance of substance x
- Ux is the urine concentration of substance x
- Px is the plasma concentration of substance x
- V is the urine flow rate.
- The product of Ux times V equals the excretion rate and has dimensions of amount per unit time
(e.g. mg/min or mEq/day).
amount of blood flowing into the kidney is __________
renal blood flow (RBF)
renal blood flow is _____% of the cardiac output
it is ______ proportional to the pressure difference between the renal artery and renal vein.
it is ______ proportional to the resistance of the renal vasculature
20-25%
directly
indirectly
______________ of renal arterioles, which leads to decreased RBF
Vasoconstriction
___________ of renal arterioles, which leads to increased RBF
Vasodilation
Due to the normally high ____ seen in the glomerulus of the kidney, the fluid entering the proximal convoluted tubule in just a _____ is greater than the total blood plasma volume.
Obviously a good portion of this fluid must be returned to the blood.
GFR
half hour
_________ is the return of most of the filtered water and many of the filtered solutes to the blood.
Reabsorption
Under normal conditions, ____% of the filtered water is reabsorbed, with the proximal convoluted tubule making the largest contribution.
Solutes are reabsorbed by both active and passive processes. These solutes include: _____
99%
Na+, K+, Ca2+, Cl-, HCO3-, HPO42-
(bicarb and phosphate)
As the fluid passes along the proximal tubule, cells located downstream ___ the ______ processes to maintain homeostatic balances of water and selected ions.
fine tune
reabsorption
A substance being reabsorbed from the tubular fluid has two options before entering the peritubular capillaries:
It can move ____________
between (paracellular) or through adjacent tubule cells (transcellular)
__________ faces and contacts the tubular fluid.
Normally has various cells surface specializations that increase absorptive surface area (e.g. microvilli) as well as some transporters.
Apical membrane
_________ faces and contacts the interstitial fluid at the base and sides of the cells.
Contains different junctions, pumps and transporters such as tight junctions and the Na+/K+ pump
basolateral membrane
_______ surround and join the neighboring cells to one another (much like the plastic rings that hold a six-pack of soda cans together).
Tight junctions
The third major function of the nephrons and collecting ducts is________________-the transfer of materials between the blood and tubule cells into the tubular fluid.
Commonly secreted substances include: _______
tubular secretion
H+, K+, NH4+, creatinine, and certain drugs such as penicillin
Two important outcomes result from tubular secretion ?
- The secretion of H+ helps control blood pH
- The secretion of other substances helps to eliminate them from the blood stream/body.
Kidney acts ______ but __________
Blood volume_____, if arterioles don’t expand to meet this pressure enough (_____) then the increase in pressure causes excess volume to be excreted by the kidneys.
slowly
significantly
increases
capacitance
Wait, isn’t the kidney just a filter for the blood?
- It is, but it is also the primary regulator of ________.
- Renal blood flow is significant.
blood volume
Far more blood flows through the kidneys than is needed for nutrient supply and waste removal
Why?
Fluid regulation via filtration and reabsorption
pressures of renal system
Systemic pressure (arterial) = Renal Artery pressure.
Systemic venous pressure is much lower, 3 to 4 mmHg
Autoregulation of RBF is accomplished by ________.
changing or adjusting renal vascular resistance
If ______ changes, a proportional change occurs in renal vascular resistance to maintain a constant RBF.
- RBF remains constant over the range of arterial pressures from _____ mm Hg (autoregulation)
arterial pressure
80-170
Main Mechanism for Autoregulation of RBF
myogenic mechanism
what is myogenic mechanism?
where the renal afferent arterioles contract in response to stretch
Thus increased renal arteriole pressure stretches the arterioles, causing the smooth muscle to contract and thus increase resistance to maintain a constant RBF.
