Chapter 13 Nephrons Flashcards
Nephron is smallest functional unit of the? And what is the function?
Kidney- filters blood
Counter current exchange allows?
hyperconcentration of substances
What is counter current exchange?
a pair of adjacent channels or tubes containing fluids flowing in opposite directions
Inside a counter current exchange there are? which allow?
gradient in between the 2 channels/ tubes which allow a flow between the two currents
when flowing in the same direction it is called?
equilibrium
what does equilibrium mean?
it means it is not concentrated that you have not accumulated heat, ion, salt (solute), etc. and stored it away
Why were we able to have create an electrical signal with the neurons?
Concentration Gradient, stored the ions / accumulated them somewhere and bc you accumulated them there was a difference / a gradient that you used
Stored it, created a concentration gradient and when you opened up the gate it releases the ions that go down the gradient
Reaching equilibrium means ?
no gradient, there is no stored substance / energy to work with and that is a problem / something we do not want to use inside of the Kidneys
The arrangement of tubes in THE SAME DIRECTION means that eventually
the concentration gradient will be reduced, and the flow will equalize across the two tubes
The arrangement of tubes in OPPOSITE FLOW DIRECTIONS means
that even as the bottom tube starts with lower concentration and picks up solutes, it will not reach equilibrium and will continue to pickup solute, as the concentration gradient always leads from the top tube to the bottom tube..
concentration is relatively higher in the?
top tube
In the exchange system heat? which moves? Reaches? Preventing?
drops which lowers the temp. moves to the right doesn’t reach equilibrium preventing same gradient
Exchange system allows you to
transfer as long as tubes are running togtehr
Countercurrent Exchange Tubes are
going in different directions
Substance can be protein, ions, solute, etc.
In this example, it is heat transfer
Heat will move from the Hotter Tube to the Colder Tube
countercurrent exchange system prevents
equilibrium because the gradient remains the same
In the counter current exchange sytem what must you do to the tubes in order to reach equilibrium
make them longer, you get more and more concentrated
Countercurrent Exchange –is in a _____Environment?
Cold Environment - you want to concentrate heat do not want it to go out – hold on to
In Warmer Environment, the Venous return is going to be
superficial veins
in a warm environment you want to
release heat / radiate heat out by taking arteriole blood which is coming from the core bc it is coming from the core it is carrying heat with it and you pump it out to the appendages
In the Warmer Environment the best way to get rid of heat is to
carry the blood to the surface of the body where you can radiate the heat, sweat, the sweat evaporates & carries heat away with it – how you cool yourself down
what caries the blood in the nephron system
efferent arteriole
where does the filtration occur in the nephron system
glomerulus
A COUNTERCURRENT EXCHANGE SYSTEM can only work if there is an
asymmetry in the system
In the case of the kidney, salts are being transported to
concentrate salts in the urine.
you are going to be able to conserve Water bc the more concentrated your urine is
the less water you are losing to your external environment, and the more you are retaining for yourself inside of your Body`
The reason we lose water in our urine is bc
some of the Waste Products that we are creating (like Protein breakdown) have to be dissolved in a solution in order for you to get rid of them so matter what you have to lose some water in order to get rid of some of the waste
the distal convulated tubule is a peice that?
afferent and efferent arterioles
Papilla is where
all the collecting ducts are emptying
after urine drians into the renal papila it drians into the ____ next?
minor calyx
there is a Mass of Cells at the Junction of the Arterioles in the DCT referred to as
apparatus
The major component of Blood is
plasma
the major component of plasma is
water
the major component of urine is
water
The more water you have the pressure
increases
the less water you have the pressure
decreases
So when you are dehydrated and do not have as much water in your system meaning pressure ____? What responds to it?
pressure decreases
Apparatus responds
Bowman’s Capsule / Glomerulus Capsule
has particular cells that are creating the lining
Filtration slits
Cells have extensions and the extensions coming off of the cells have gaps in between
Through the Filtration Slits you have access to the one layer
the Endothelium of the Capillary Wall
Why is the water flowing in that direction / what is driving it?
In essence, there is a little bit higher pressure inside of the Vessel than the outside of the Lumen
Goes from the Lumen of the Blood Vessel into the Lumen of the Bowman’s Capsule and when that happens it carries dissolved substances with it
what you are trying to carry out of the Blood is? and into?
waste products and into the Lumen of the Bowman’s Capsule
Inside of the Bowman’s Capsule is? and goes to?
not urine yet but Filtrate – water with dissolved Solutes in it and it goes to the PCT
Proximal Convoluted Tubule
initiate concentration of glomerular filtrate
About __% of ____ removed by ___ transport here, and ____ follows passively.
75% of sodium is removed by active transport and chloride follows
Remaining fluid in nephron tube is about same concentration as that of surrounding ____.
interstiatial fluid
Remaining fluid reduces to about __% original volume
25%
What gives you a better opportunity to remove Waste Products
multiple filters so nothing gets clogged
We have created a filtrate which is inside of the _______ of the Nephron
Lumen of the tubules
What is in the Lumen is now (for all intends and purposes) ____ of your BODY
outside
If you are taking something like Water, fluid, salt, etc. and you take it out of the Lumen
you have filtered it and pushed it in to the Lumen with Water Pressure, Fluid Pressure, etc. now it is on the outside of your Body
if you then take some of the Fluid back into your Body that is called
reabsorption
*Na has a ___charge, Cl has a ___charge and how do they work together?
*Na+ has a positive charge, Cl- has a negative charge
they are attracted to each other so when you actively remove the Na+ and you reabsorb the Na+ the Cl- is going to passively follow bc it is attracted to the Na+ so you are also going to reabsorb Cl-
loops of henle
Acts in manner of counter current exchanger
Note that each limb of loop has
fluid moving in opposite directions (even thought hey are connected at one end)
loops of henle further concentrates?
urine
Also means that salt concentration will be highest near ______.
bend in the loop
Ascending loop of henle put salts into?
interstiaital space
A concentration gradient IN THE INTERSTITIAL SPACE is being set up by the _____.
chloride transport
The Water is going to go out of the Lumen of the Tube and it goes into the Interstitial of the Medulla
When that happens what happens to the concentration of the Water?
The solution gets more concentrated but not as concentrated than what is in the Interstitial of the Medulla, the Medulla is also getting more concentrated bc we already used the Ascending Limb to create / set up the Concentration Gradient
You are still going to reabsorb Water
Concentrate the Solution because you reabsorb Water, gets more and more concentrated and by the time you get to the Bottom of the Loop of Henle it is?
and the rate is?
the most concentrates
the rate is the fastest
As you go up the Ascending Loop of Henle, the rate of transfer
slows down ( the lowest rate of transfer & the lowest concentration getting pumped out)
whats the second chance to excrete/ get rid of waste products
DCT
In the DCT the gradient is in the?
interstial
The DCT is affecting the?
descending limb bc wate ris permeable there
If you make the system (Loop of Henle) longer, then you are going to be able to
concentrate urine even more
Second opportunity to concentrate
collecting duct
Once it comes out of the Collecting Duct, now you will not be able to?
what you produce there is?
concentrate it anymore
what you produce there is as concentrated as you are going to make the urine / not filtering it out anymore
Collecting ducts recieves from many?
distal convulted tubules
By setting up a countercurrent system, a salt concentration gradient is set up in the
interstitial space of the Medulla
lower conc. next to the?
Cortex
As fluid in collecting tubules reacts to concentration gradient, water is ____, concentrating filtrate as ____.
pulled out
concentrating filtrate as urine
part that contains the convoluted tubules and proximal part of Loop of Henle, and proximal part of collecting tubules
cortex
contains distal part of Loop of Henle, and distal part of collecting tubules. Where most of the active transport takes place.
medulla
Kidneys are intimately tied to?
fluid regulation (water balance), and therefore blood pressure regulation
The way you increase Blood Volume is by increasing the amount of
water that is in your blood
The Amount of water to be removed or retained is controlled in part by the
kidneys
water gain is?
Ingested food and fluid; metabolic water
water loss
urine, feces, sweat, evaporation at lungs or skin.
Urine production controls
how much water you are going to lose in your urine affecting water balance
In regards to urine production, the most important hormone is
ADH (anti diuretic hormone)
ADH makes the DCT and collecting duct ___permeable to_____?
MORE permeable to water
Diuresis
Anti
– increasing urination / more urine,
– not going to produce as much urination
