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Revised August 2015 Name ______________________________
REVISED Renal Anatomy and Physiology Worksheet
- On the diagram below label the major organs of the urinary system.
- List the major functions performed by the kidneys. List as many as your textbook (or professor) has given.
- On the diagram below label the major parts of the kidney.
outermost connective tissue
conduit for blood vessels & nerves space space region region region
rounded tip
entire structure
space tube
- On the diagram below label the parts of the cortical and juxtamedullary nephrons and other non- nephron parts of the kidney.
capillaries
specialized cells
duct - not part of nephron
rounded tip
space - not part of nephron
- Which nephron above (A or B) is the cortical nephron and which is the juxtamedullary nephron?
A is the _____________________________ B is the __________________________
- a. Draw at least one arrow in each labelled part of the cortical and juxtamedullary nephrons above to indicate the direction of fluid flow. The more arrows the better.
O U T E R
C O R T E X
B A M E D U L L A I N N E R M E D U L L A
capillaries
specialized cells
d. Fill in blanks to trace urine flow from collecting duct to outside a female’s body.
collecting duct
___________________________ duct through ___________________________
___________________________ wide area
___________________________ tube
___________________________ hollow muscular organ
___________________________ sphincter (involuntary)
___________________________ tube
___________________________ sphincter (voluntary)
___________________________ opening to exterior
e. Fill in blanks to trace urine flow from collecting duct to outside a male’s body.
collecting duct
___________________________ duct through ___________________________
___________________________ wide area
___________________________ tube
___________________________ hollow muscular organ
___________________________ sphincter (involuntary)
___________________________ tube
___________________________ sphincter (voluntary) (omit membranous urethra)
___________________________ tube
___________________________ opening to exterior
- Three nephron processes are responsible for producing urine. On the simplified diagram below label each of these 3 processes on the bold label lines.
afferent arteriole
glomerular capillaries
efferent arteriole
Bowman’s capsule cortical radiate artery
peritubular capillaries
rest of nephron (proximal convoluted tubule through collecting duct)
urine
- Each of the 6 diagrams below is similar to the one above. Based on the arrows shown in each diagram determine whether the substance shown is NORMALLY only filtered, only secreted, filtered and completely reabsorbed, filtered and partially reabsorbed, filtered and secreted, or filtered and partially reabsorbed and secreted. THEN, name a substance that the nephron handles in exactly the manner shown.
a. This substance is __________________________
Optional: An example of a substance handled by the nephron in this manner is ________________
urine
e.
This substance is __________________________
An example of a substance handled by the
nephron in this manner is ___________________
urine
f.
This substance is __________________________
An example of a substance handled by the
nephron in this manner is ___________________
urine
- Write the names of renal blood vessels on the blanks below to indicate the direction of blood flow through a kidney. Note that the first line, “aorta” has been filled in for you, as have the names of some of the arteries and veins. On the three lines labelled “capillaries” you are to write the names of those particular capillaries.
aorta
segmental artery interlobar artery arcuate artery
______________________________ capillaries
from both cortical & from juxtamedullary juxtamedullary nephrons only nephrons
___________________ capillaries __________________ capillaries
cortical radiate (interlobular) veins arcuate vein interlobar vein
inferior vena cava
- a. Calculate a numerical value for net filtration pressure (NFP) in the peritubular capillaries using the values given below. Peritubular capillary blood (hydrostatic or hydraulic) pressure is 20 mm Hg; hydrostatic (hydraulic) pressure in interstitial fluid outside the capillaries is 3 mm Hg; colloid osmotic pressure of blood in the peritubular capillaries is 33 mm Hg; and colloid osmotic pressure of the interstitial fluid is 6 mm Hg. Please show your work and include units with your answer.
b. Does your answer to the above question indicate that filtration or reabsorption is occurring across the peritubular capillaries?
- The following are cause and effect chains of events. In each a sideways arrow () means “causes.” An up arrow () means “increases.” A down arrow () means “decreases.” Always assume that any items or variables not listed remain unchanged and so can be ignored. Fill in each blank with either an up arrow, a down arrow, or No to indicate “no change” in the listed variables. As an example to get you started, the blanks in the first chain of events have been filled in for you.
a. afferent glomerular capillary NFP GFR arteriole blood pressure constriction renal blood flow
b. afferent ____ glomerular capillary ____ NFP ____ GFR arteriole blood pressure dilation ____ renal blood flow
c. efferent ____ glomerular capillary ____ NFP ____ GFR arteriole blood pressure constriction ____ renal blood flow
d. efferent ____ glomerular capillary ____ NFP ____ GFR arteriole blood pressure dilation ____ renal blood flow
e. both afferent ____ glomerular capillary ____ NFP ____ GFR and efferent blood pressure arteriole constriction ____ renal blood flow equally
- a. Below is part of the wall of a generalized nephron, i.e., the cells could be from any part of the nephron - the proximal or distal convoluted tubule, thin descending or thin ascending limbs of Henle’s loop, thick ascending limb of Henle’s loop, connecting tubule, or the collecting duct. Label the parts shown. Words in small font beneath the lines provide additional information to guide you. Of course not all parts of the nephron are composed of the non-microvilli simple cuboidal cells shown in the diagram. So in parts b.-d. at the bottom of the page name the nephron segment(s) composed of the cell type listed.
Fluid Flow Blood Flow
space
seal epithelial cell of nephron
this particular surface or membrane
this particular surface or membrane
route through cell
route through seal and between cells
fluid or space
blood vessel
b. In the __________________________________ the simple cuboidal cells all have microvilli. 1 nephron segment
c. In the ______________________________________________________________________ 2 nephron segments the cells are simple squamous cells.
d. In the ______________________________________________________________________ 4 nephron segments the cells are mainly simple cuboidal cells (without microvilli) as shown above.
b. Specific directions: Show how H 2 O, Cl−, K+, Ca2+, and urea are reabsorbed from luminal filtrate to blood across the proximal convoluted tubule below. You may wish to start by redrawing the reabsorption of Na+^ from the previous page as a reminder that all of these substances follow Na+. Draw and label aquaporin channels for water. Transporters and channels for other substances do not have to be shown. Draw arrows (as described in the general directions on page 12) to show the pathway(s) for reabsorption of each of the substances above. Show which substances are reabsorbed via the transcellular route, which via the paracellular route, and which via both routes.
interstitial peritubular lumen fluid capillary
fluid flow ↓ blood flow ↓
PCT cell
PCT cell
PCT cell
c. Specific directions: Show how the proximal convoluted tubule removes bicarbonate ion, HCO 3 −, from the filtrate and adds it to the blood. Show that this process is not technically reabsorption because the HCO 3 −^ removed from the filtrate is not the same one that is released into the blood. In the lumen write the complete chemical reaction of HCO 3 −^ with H+^ to H 2 CO 3 and then to CO 2 and H 2 O. Show which step is catalyzed by a famous enzyme. Draw in the location of the enzyme and label it. Show which substance(s) can cross the apical (luminal) membrane and enter the cell. Use the appropriate arrows described in the general directions on page 12. Next write the complete chemical reaction that these substances undergo within the proximal convoluted tubule cell being sure to show again which step is catalyzed by the famous enzyme and labelling that enzyme. Lastly, use the appropriate arrows to show the correct movement of the products of this chemical reaction out of the cell, into the interstitial fluid and peritubular capillary blood.
interstitial peritubular lumen fluid capillary
fluid flow ↓ blood flow ↓
PCT cell
PCT cell
PCT cell
- On page 17 is a diagram of a juxtamedullary nephron, well, at least most of one. It includes Bowman’s capsule, proximal convoluted tubule, descending limb of the loop of Henle, thin and thick ascending limbs of the loop of Henle, and the distal convoluted tubule. Collecting ducts for this nephron are shown on pages 19 & 20. The general instructions for page 17 are to show which substances are reabsorbed and/or secreted in each segment from the proximal convoluted tubule through the collecting duct. For each substance use the symbol drawn across the nephron’s wall to represent active transport, either primary or secondary, and the symbol also drawn across the nephron’s wall to represent passive transport. Of course each arrow could be coming out of the tubular fluid to represent reabsorption or going into tubular fluid to represent secretion. The line representing the nephron’s wall is a composite of BOTH the luminal (apical) and basolateral (basal) membranes. If a substance is actively reabsorbed or secreted across either membrane, use the active transport symbol ( ) to show its movement. If a substance is passively reabsorbed or secreted across both membranes, use the passive transport symbol () to show its movement. Specific instructions for each nephron segment follow. A curved arrow glancing off the nephron’s wall shows that the nephron segment is impermeable to that substance. These curved arrows have been added for you on page 17.
PROXIMAL CONVOLUTED TUBULE: In the proximal convoluted tubule segment of the nephron on page 17 use the symbols or to show the reabsorption or secretion (if applicable) for each of the following substances: Na+, H 2 O, Cl, K+, Ca2+, HCO 3 , H+, urea, glucose, and amino acids. Label each symbol with the substance being reabsorbed or secreted. As an example Na+, H+, and H 2 O have been done for you. Note: Here we simplify HCO 3 − handling and say it is reabsorbed. As you showed on page 14, the HCO 3 −^ ion that enters the blood is not the same one that was filtered. However, the net effect is that HCO 3 −^ is removed from the filtrate and added to the blood as if it had been reabsorbed.
DESCENDING LIMB OF THE LOOP OF HENLE: In the descending limb of the loop of Henle on page 17 use the appropriate symbols to show the reabsorption or secretion (if applicable) of H 2 O and urea. The curved arrow with Na+Cl−^ at its end shows that this segment is impermeable to Na+^ and Cl−.
THIN ASCENDING LIMB OF THE LOOP OF HENLE: In the thin ascending limb of the loop of Henle on page 17 use the appropriate symbols to show the reabsorption or secretion (if applicable) of Na+, Cl, and urea. The curved arrows with H 2 O show that this segment is impermeable to water.
THICK ASCENDING LIMB OF THE LOOP OF HENLE: In the thick ascending limb of the loop of Henle on page 17 use the appropriate symbols to show the reabsorption or secretion (if applicable) of Na+, Cl, and K+. The curved arrows with H 2 O and urea at their ends show that this segment is impermeable to both water and urea.
DISTAL CONVOLUTED TUBULE: In the distal convoluted tubule on page 17 use the appropriate symbols to show the reabsorption or secretion (if applicable) of Na+^ and Cl, and then Ca2+^ when parathyroid hormone (PTH) is present. The curved arrows with H 2 O and urea at their ends show that this segment is relatively impermeable to both water and urea. (Note: Connecting tubule will be included with the collecting duct in the next section.)
Na+^ H 2 O
H+^ to collecting duct
Na+Cl−
Na+Cl−
H 2 O
H 2 O
urea
H 2 O urea
H 2 O for H 2 O essentially unable to pass through collecting duct (see example on p. 17)
Lastly, at the bottom of each side of the collecting duct, circle the most appropriate Na+, Cl−, K+, and H 2 O contents of the urine produced.
COLLECTING DUCT UNDER HIGH AND LOW K+^ CONDITIONS: The purpose of this section is to show the net reabsorption and/or net secretion of K+^ under conditions of high K+^ (left side) and low K+^ (right side). In this section ignore the effects of acidosis/alkalosis. They will be covered in the next section. Also, because the collecting duct is constantly reabsorbing some K+ and can only change K+^ secretion, show only the net K+^ reabsorption or net K+^ secretion. Use the symbol K+^ or K+^ to show net active transport of K+, and K+^ or K+^ to show net passive transport of K+. Lastly, at the bottom of each side of the collecting duct, circle the most appropriate K+^ content of the urine produced.
COLLECTING DUCT DURING ANIMAL PROTEIN DIET/ACIDOSIS OR VEGETARIAN DIET/ALKALOSIS: The purpose of this section is to show how the collecting duct is involved in acid-base regulation by reabsorbing or secreting H+^ and HCO 3 −^ and how this process affects K+ reabsorption/secretion. At the top of each collecting duct, write the type of intercalated cell carrying out the transport processes you will show below. Use the following symbols to show the movement across the collecting duct: H+^ or H+^ for active transport of H+ H+^ H+ or for the active transport exchange of H+^ for K+ K+^ K+ HCO 3 −^ or HCO 3 −^ for passive transport of HCO 3 −
Lastly, at the bottom of each side of the collecting duct, circle the most appropriate H+, HCO 3 −, and K+^ contents of the urine produced.
- ADH ADH + aldosterone aldosterone
interstitial interstitial fluid fluid and and blood blood
more Na+^ in urine more Na+^ in urine more H 2 O in urine more H 2 O in urine less Na+^ in urine less Na+^ in urine less H 2 O in urine less H 2 O in urine more Cl^ in urine more Cl^ in urine large urine volume large urine volume less Cl^ in urine less Cl^ in urine small urine volume small urine volume more K+^ in urine more K+^ in urine iso-osmotic urine iso-osmotic urine less K+^ in urine less K+^ in urine hyperosmotic urine hyperosmotic urine more H 2 O in urine more H 2 O in urine hypo-osmotic urine hypo-osmotic urine less H 2 O in urine less H 2 O in urine
