Exam 3 Flashcards
Renal Phys
In terms of osmotic pressure, what way does water diffuse?
to the area with the greatest osmotic pressure
What has a higher osmolarity a dilute or concentrated solution?
concentrated
The kidneys are located ____ and slightly _____ in the lumbar region
dorsally and slighly posteriorly
T/F Simple diffusion is the organized movement of molecules with transporters
False, it is the random movement of molecules. (Brownian motion)
Is energy required for active transport?
Yes
T/F The osmolality of a urine sample which has both ionized and undisassociated substances measures 300 osmol of .15 mol/L exerts different osmotic pressure than 1 L of solution that has 300 osmol of 0.3 mol/L of glucuse which is intact.
F-same osmotic pressure.
T/F one kidney is usually more cranial and less attached to the abdominal wall.
False, one kidney is more cranial and more attached to the abdominal wall
A hypotonic solution has a _____effective osmotic pressure than red blood cell solution.
lower
What is the effect of decreased Na+ concentration in the extracellular fluid?
ECF osmolarity decreases
What 2 characteristics will make diffusion go faster?
A larger gradient and a more permeable membrane
Name four ways solutes interact at biological membranes
Diffusion facilitated diffusion active transport secondary active transport
In simple diffusion, if there is a concentration gradient, what way do molecules, ions or particles move?
Down a concentration gradient or from high concentration(High % of solutes) to low concentration.
When Na+ leaks into cells what happens?
Na+K+ATPases pump them back out at about the same rate.
What is the difference between secondary and primary active transport?
Transporter does not hydrolyze ATP and uses potential energy from elsewhere in the cell.
What is one of the main tasks of the kidney?
To control the osmolarity of the animal
T/F Glucose is an effective osmol
True-it cannot cross membranes
Water moves from ____ to _____ concentration.
high to low
What species can this kidney be found in?
Cat, Dog, Sheep and Goat
An effective osmole, generates __________, because it creates a ______ in water concentration.
n osmotic pressure, difference.
Movement of Na+ at the basolateral membrane of the proximal tubule uses _____by Na+K+ATPase.
Active transport
during simple diffusion what makes it faster?
A bigger gradient and a more permeable membrane
Diffusion is the movement of solute _____ or _____ its concentration gradient.
Down or with
At the luminal membrane of the proximal tubule the movement of glucose and amino acids move solute _______their concentration gradient using ____generated by the ____ movement of Na. This is called ______
against , potential energy, downhill, secondary transport
What is the Hilus do in the Kidney?
It is the cleft where the renal artery, renal vein and ureter enter the kidney
When NaCl disassociates to for Na+ and Cl-, How many osmols does .5 mole of substance equal?
1 osmol
Which would have a greater effect on the volume of a cell at equilibrium: solution A composed of 300 mosM NaCl and 200 mosM urea, or solution B composed of 200 mosM NaCl and 300 mosM urea?
Solution B- Hypotonic to the cell. Water will move in Solution A would be isotonic to the cell because urea is a penetrating solute.We can ignore its concentration at equlibrium. This solution is isotonic to the cell.
Can NaCl easily penetrate most cell membranes?
No- because they are charged ions
Ca 2+ is how many mEq?
300 mEq/L
How long does simple diffusion occur for?
Until equlibrium
what is osmosis?
diffusion of water
what is osmotic pressure?
quantitative measurement of the tendency of water to diffuse
Facilitated diffusion is the solute _____ or _____ its concentration gradient
down or with
In terms of particles, what determines osmotic pressure?
the number of particles
this is the kidney of what animal?
Cow
T/F Energy is not required for facilitated diffusion
True
How is energy provided during active transport?
Via the hydrolysis of ATP by a solute.
What is electrochemical equivalence?
Same as molarity but assumes not all solutes have the same charge. (H+ has half the Charge of Ca2+)
How do we define concentration in terms of fluid therapy?
% or parts of solute per 100 of solvent
T/F diffusion is slower at high concentrations
F-faster
Active transport is an ______ movement and ______energy.
uphill, requires
What kidney is located more cranially?
usually the right except in the pig
This is the kidney of what animal?
Horse
How much water makes up the body?
60%
what is the universal physiological solvent?
Water, solvent for chemicals in the body
Solute moves from ____ to _____ in secondary active transport.
low to high
In Osmosis does water move from an area where water concentration is higher or lower?
Water moves down its concentration gradiet Water will move to the area with high solute low water concentration.
What are the membranes of cells generally made of?
Lipid Bilayer (Thin film of lipid)
What is a concentration gradient?
A difference in concentrations
T/F Knowing the osmolarity of a solution can tells us its tonicity
False - we need to know if the soluts are pentrating
What is tonicity of a solution?
The amount of effective osmols in a fluid.
What will happen if a Red Blood cell is put in a hypotonic solution?
It swells and the solution is said to be hypotonic to plasma
In active transport solutes move ______ and _____ its concentration gradient
up and against
Why is water ideal for transporting media into cells and throughout the body? ?
High specific heat (heat can be absorbed without a large temp. increase) Provides lubrication to minimize friction
T/F Diffusion requires energy
False
What is Molarity?
A more precise term for defining the amt. of solute (in moles) (moles per liter)
How is osmolarity different from molarity?
disassociation Concentration of NaCl-moles of NaCl per liter Osmolarity od 1 M NaCl solution = 2 Osm (1 mole contains 2 moles of potentially osmotically active ions. (Na and Cl)
what species is this structure found in?
Pig
The transprt or Na+, K+, and Cl- in the macula densa to monitor glomecular fileration uses ______ across the membrane
facilitated diffusion
In moles what is the concentration of NaCl in physiological saline?
150 mM
In the luminal membrane of the promixal tubule how does glucose and other amino acids move into the cell?
Secondary active transport-Na+ goes into cell via a gradient established by NA+K+ATPase and that enegry is used.
What contributes to the tone of a solution and what is it called?
Only particles that for which a membrane is not permeable called an effective osmol.
Kidneys release _____ that is important in regulating blood pressure
renin
Water moves from _____ to _____ Osmolarity.
Water Moves from Low to High Osmolarity.
When is facilitated diffusion used?
If the membrane is not permeable to solute (polar or charged)
What is an effective osmole?
A solute on one side of a membrane (it cannot penetrate) creates a difference in water concentration tthat which creates osmotic pressure.
What makes the kidney difficult to discern?
perirenal fat-protective function
What does the kidney do?
Clean the blood Maintenance of extracellular fluid Endocrine function
Solute moves from ____ to ______ during active transport.
low to high
_____ is released from the kidney and aids in red blood cell production
EPO
What does facilitated diffusion use for transport across the membrane?
Transporters or pores
_________gradients are critical in driving both solute and slovent accross membranes.
Chemical
T/F in a normal state the solution of erythrocytes is in osmotic equilibrium with plasma
True-
How does the kidney clean the blood?
Filters blood to produce an ultrafiltrate Selectively reabsorbs desired components and returns them to bloodstream/
If a cells volume increases in response to a solution, the solution is said to be ____ to the cell.
Hypotonic
What provides the energy in active transport?
hydrolysis of ATP
What is an example of simple diffusion in the kidney?
In the late proximal tubule, paracellular Cl- is reabsorbed.
Diffusion is a _____ movement.
downhill
What can cross a lipid bilayer?
lipid soluable molecules like oxygen and CO2
What is one of the most important functions of the kidney?
Handle water and Na+
In Secondary active transport, solute moves _____ or _____ its concentration gradient
up or against
Where is the kidney situated on each side?
Fossa of the liver
In a practical sense, what is the tone of a solution infused into the blood compared with?
The solution inside RBC’s
What is molality?
moles per kg of solvent
What is required on facilitated diffusion?
a transporter
high osmotic pressure occurs when?
when there is a greater number of particles
In the kidney how does glucose move into the cells?
Active transport (Glucose into blood from lumen-low to high)
What uses active transport in the kidney?
Na+K+ATPase moves Na+ at the basolateral membrane of the proximal tubule and other nephron sections.
How many kg is 1 L
1 L if water = 1 kg
What is the main difference in active transport and secondary actuve transport
In secondary active transport, ATP is not hydrolzed by the transporter, instead ATP generated in other areas of the cell for energy and this process usesit as potrntial energy
What is the electrochemical equlivance of saline?
One equlivant (eq) combines with or replaces 1 mole of H+Na+ in saline is about 150 mEq/L
What happens to red blood cells in a hypertonic solution?
They shrink called crenated cells.
How many Eq is one mole of Ca2+?
2
Where can facilitated diffusion be observed in the renal system?
In monitoring glomerular filteration, NKCC2 transports Na+, K+ and Cl- in the macala densa
How does glucose move in most areas of the body into the cell?
Facilitated diffusion
What is central to how the kidney works?
Osmolarity Differences
What is a hypotonic solution?
It has a lower effective osmotic pressure than the solution of RBCs
1 eq is equal to what?
Same charge (positive or negative)
In the late proximal tubule of the kidney, paracellular reabsorption of Cl- uses _______
Diffusion
What is the percent concentration of physiological saline?
0.9% NaCl (parts per 100)
You place a cell with an internal concentration of 300 mosM in a 400 mosM solution. What happens to the volume and osmolarity of the cell at equilibrium?
We don’t know what happenes to the volume cause we don’t know if the solute is penetratable or nonpenetrateable Osmolarity increases Thus you can predict that the cell will become more concentrated, either because water moves out into the solution, or because penetrating solute moves into the cell. You do not know the solutes in the solution, and you do not know the relative volumes of the cell and the solution. Without this information, you cannot say what the actual osmolarity will be at equilibrium. You can only say that osmolarity has increased.
What is active transport?
Movement `opposite to natural diffusion, usually needs a carrier
If water is the universal solvent why cannot it easily go into cells?
The lipid bilayer is hydrophobic
For osmosis to occur, the membrane must _____permeable to the solute in question
Not (otherwise it would move down its concentration gradient until water inside = water outside)
T/F Energy is required for simple diffusion
F
T/F Knowing the osmolarity of a solution can tells us its tonicity
False
T/F The kidneys are located outside the perintoneum
True called retroperitoneally
T/F diffusion is passive
True-no energy required
What is it called when ions or molecules are at the same concentration?
Equilibrium
If Na+ is in solution would it move to where there is more Na+ or less?
Less, it always moves from high to low concentration by diffusion regardless of the presence of other substances
How much cardiac output does the Kidney receive?
25%
How does water get into a cell?
Through protein channels that provide pores for water and water soluable substances.
1 Osmol = ?
1 mole of nonionized or nondisassociated substance
In facilitated diffusion what way do molecules move?
High Concentration to Low
T/F Ions always generate osmotic pressure
F- since membranes differ in permeability, just because something that can generate osmotic pressure does not mean that it always does.
The difference between the cortex and medulla is ________ and _________.
physical and chemical
Dogs and cats have a _________ kidney
Unilobular
Where is the renal papilla?
At the base of the renal pyramid
What does the structure of the renal papilla have?
An area full of holes called the area cribosa
In unilobular kidneys what is the renal papilla called?
Renal crest
why is the renal papilla full of holes?
To allow drainage of urine from the medulla to the renal pelvis
What is the functional unit of the kidney?
The nephron
What lines the nephron?
epithelium
what are the two types of nephron?
cortical and juxtamedullary
Where does the cortical nephron turn?
outer medulla
where does juxtamedullary nephron turn?
inner medulla
How do the different types of nephron differ?
Ability to absorb various things and the way they respond to some hormones. We can attribute this to the difference in location
Dogs and cats only have a ________nephron
juxtamedullary
Beavers only have a ______ nephron
cortical
Where are the renal corpuscles found?
Only in the cortex
What type of tubules are found in the cortical labyrinth?
proximal and distal convoluted tubules
What is found in the outer zone of the medulla?
loops of henle, distal straight tubules, and collecting ducts
where are the collecting ducts located in the kidney and what is their function?
Inner Medulla and transport urine to the renal crest.
Where is the site of filtration?
Renal corpuscle
What is the first step in renal physiology?
Filteration
How does the glomerulus filter blood?
Blood enters and it is squeezed through walls of capillaries
Where does the filtrate from the glomerulus collect?
Bowman’s capsule
Where do the capillaries enter on the renal corpuscle?
The vascular pole
Where does the proximal tubule leave the renal corpuscle?
At the urinary pole
What generates high pressure in the glomerulus?
The stretchiness difference of arterioles
What arteriole generates more resistance to blood flow, afferent/efferent?
Efferent
The _______ comes back around to make contact with the arterioles/glomerulus in a region called ____
distal straight tubule, macula densa
Why are the capillaries of the glomerulus fenestrated/
to allow blood to get filtered into the urinary space.
The intraglomerular cells are called _______ and they are ________, ___________ and __________
mesangial cells, supportive , contractile, and phagocytic
where are the extraglomerular mesangial cells located?
vascular pole
What are extraglomerular cells important for?
renin-angiotensin system
The macula densa is in close association with _______ __________ _________ and has no _______ ____________.
extraglomerular mesenglial cells, basal lamina.
The visceral layer of the glomerulus makes _______ contact with the ________ and is the ________
layer
What type of epithelium is the parietal layer of the renal corpuscle?
simple squamous
What type of cells are found in the visceral layer of the renal corpuscle?
podocytes-help with filtration
Podocyes in the visceral layer of the glomerulus have
specilized processes called pedicels that wrap around capillaries and interdigitate with other podocytes/pedicels.
The epithelium of the filtration has ______ to aid in the 1st step of filtration.
pores of different sizes in the capillaries
The capillaries are enveloped in
cells
The macula densa is part of _________ tubule and ______ part of the glomerulus
distal, not
The juxtamedullary nephron and cortical nephron differ by _______ and _______.
location and depth of loop of henle
Where is the basal lamina in the renal corpuscle?
in the visceral layer
What is the glomerular basement membrane composed of?
lamina rara (interna and externa) and lamina densa
plasma passes through 3 filters: _______ _______ and ______
fenestrated capillary, glomerular basement membrane and a slit diaphram
Filtration in the renal corpuscle is based on ______ and ______.
size and charge
the capillaries of the glomerulus are covered in ______ and ________ which ______ negativly charged molecules.
laminin and fibronectin, repel
the filtration barrier repels ______-
negatively charged ions
Which of the following anatomical portion of a nephron connects the Bowman’s capsule to the loop of Henle?
Proximal convoluted tubule
As glomerular filtrate moves through the ascending loop of Henle, the filtrate becomes more dilute: why?
The ascending loop of Henle is permeable to ions but impermeable to water
Most reabsorption occurs in the _______
proximal tubule
Which molecule is entirely reabsorbed in the proximal tubule?
Glucose
If increase the diameter of the afferent arteriole then
The GFR decreases
Blocking production of renin in juxtaglomerular cells cause urine production to
increase
The nephron is bad at reabsorbing _______
proteins
What drives fluid movement out of the glomerulus?
hydrostatic and onconic pressures
Where is the protein concentration higher?
Capillaries-generates an osmotic pull of fluid into the capillaries
Clinical evaluation of renal function is done by measuring _______ and _________.
Creatine or BUN
