Question

Can you paraphrase the following rationale for me, thank you!

Urinary System

1. Blood in the renal arcuate arteries flows next into which vessels?

a. Afferent arterioles

b. Efferent arterioles

c. Glomerular capillaries

d. Interlobar arteries

e. Interlobular arteries

Rationale:

The blood that goes to kidneys passes thru the INTERLOBAR ARTERIES first before flowing in the renal arcuate arteries. Then it goes to INTERLOBULAR ARTERIES passing thru AFFERENT ARTERIOLES then GLOMERULAR CAPPILLARIES before reaching EFFERENT ARTERIOLES.

2. Which cell type comprises the visceral layer of Bowman capsule?

a. Endothelial cells

b. Juxtaglomerular cells

c. Mesangial cells

d. Podocytes

e. Extraglomerular mesangial (or Lacis) cells

Rationale:

The inner wall of Bowman's capsule is a visceral layer, and it is composed of podocytes that closely surround the glomerular capillary tuft. Thus making Podocytes highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. This cell plays an active role in glomerular filtration by preventing plasma proteins from entering the urinary filtrate by providing a barrier comprising filtration slits between foot processes, which act as dynamic network of cellular extensions.

3. Which type of epithelium lines the thick ascending limb of the loop of Henle?

a. Pseudostratified columnar

b. Simple columnar

c. Simple cuboidal

d. Simple squamous

e. Transitional (urothelium)

Rationale:

The loop of Henle consist of two long loop lengths: one is the short loop that descends to the cortical-medullary border, and a long loop, which ascend to the renal papilla. Furthermore, there are 3 parts of Loop of Henle. (a) The short Henle loops have a descending thin limb and a thick ascending limb. The long Henle consists of thin descending and ascending thin limb followed by pars recta of the distal tubule. (b) The thin parts of the loop of Henle are lined with a single-layer flat epithelium with a high permeability for water (and ions via solvent drag) through a weak tight junction (zonula occludens). (c) The thick ascending limb of the Henle loop is lined by simple cuboidal cells without a brush border. These cells are specialized to perform a secretion and reabsorption of the substance resulting to the production of urine.

4. Which cell is a modified smooth muscle cell that secretes renin?

a. Macula densa cells

b. Mesangial cells

c. Podocytes

d. Juxtaglomerular cells

e. Endothelial cells

Rationale:

Juxtaglomerular cells are located near glumerulus that highly that synthesize, store, and secrete the enzyme renin. They are made up of specialized smooth muscle cells mainly resides on the walls of the afferent arterioles (and some in the efferent arterioles) that transport the blood to the glomerulus. In synthesizing renin, they play a crucial role in the renin–angiotensin system and thus play the role in self- regulation of the kidney.

5. Epithelial cell membrane domains containing many stiffened plaques of protein are an important feature in which part of the urinary system?

a. Juxtaglomerular apparatus

b. Bladder mucosa

c. Collecting ducts

d. Renal pyramids

e. Membranous urethra

Rationale:

The urinary bladder functions as storage reservoir for urine. Anatomically, urinary bladder is located in the pelvic cavity, posterior to the symphysis pubis, and below the parietal peritoneum. It composed of smooth muscle lining wall that is covered by a bladder mucosa thus separating muscle from the urine.

6. An immunohistochemical technique using antibodies against aquaporins to stain a section of kidney would be expected to stain cells in which structures most intensely?

  a. Collecting ducts

  b. Lining of the major and minor calyces

c. Proximal convoluted tubules

  d. Distal convoluted tubules

  e. Glomeruli

Rationale:

Immunohistochemical technique is used to detect antibody that was present in the specimen. Therefore, antibodies will aggregate where the antigens are. Since aquaporin antibodies is the basis of immunohistochemical technique stain, the target of the antibodies are the aquaporin that was found in the kidney which located at segment of collecting ducts.

7. What type of epithelium lines the prostatic urethra?

a. Simple columnar

b. Pseudostratified columnar

c. Stratified squamous

d. Simple squamous

e. Transitional (urothelium)

Rationale:

The transitional epithelium are the unique cell type structure that possess a high plasticity and defense mechanism for urethra. The urothelium stretch when filling phase of micturition reflex takes in place resulting umbrella cells to increase in size thus activation of the sensory fibers.

8. A 14-year-old patient presents in the nephrology clinic with fatigue, malaise, anorexia, abdominal pain, and fever. She reports a loss of 6 lb in the past 2 months. Serum gamma globulin and the immunoglobulins IgG, IgA, and IgM are all elevated. Her serum creatine is 1.4 mg/dL (normal 0.6-1.2 mg/dL) and urinalysis of glucose and protein are 2+ on a dipstick test, confirmed by laboratory at 8.0 g/ dL and 0.95 g/dL, respectively. A renal biopsy is prepared for light microscopy, and an infiltrate containing lymphocytes, plasma cells, and eosinophils is found among tubules having cells with prominent brush borders. Which one of the following statements correctly pertains to these epithelial cells?

a. Impermeable to water despite presence of ADH

b. The primary site for the reduction of the tubular fluid volume

c. The site of the countercurrent multiplier

d. The site of action of aldosterone e. Indirectly involved in the release of renin

Rationale:

The primary site for the reduction of the tubular fluid volume takes place mainly in proximal convoluted tubule of the nephron. Since prominent brush borders are present to the biopsy that can be only seen in PCT, PCT are the affected cell.

9. A 45-year-old man presents with nephrolithiasis or kidney stones. The process of calcium oxalate stone formation as seen in this patient begins with Randall plaques found in the basement membranes of which one of the following structures found only in the renal medulla?

a. Proximal convoluted tubules

b. Distal convoluted tubules

c. Thin loops of Henle

d. Afferent arterioles

e. Collecting ducts

Rationale:

Randall’s plaque is plaque of calcium deposited in the tissue of the renal papilla. Large amounts of Randall’s plaque plays a vital role as pre requisite to form a kidney stone. Calcification happens at the basement of loop of henle and from there, Randell plaques spread throughout kidney toward urothelium. Due to the failure on urothelium, plaques can be exposed to urine resulting to formation of renal stones. Renal stones are formed within the collecting ducts of kidney resulting to growth of crystals into stones that later will calcified. This calcified stones located in the basement membrane of the loops of Henle, from which it extended into the medullary cavity.

10. A 15-year-old male presents with hematuria, hearing loss, lens dislocation, and the onset of cataracts. Genetic analysis reveals a mutation in the COL4A5 gene. Transmission EM examination of a renal biopsy confirms that the disorder has affected a component of the renal corpuscles in which damage disrupts normal glomerular filtration. Which one of the following structures would most likely be abnormal in the TEM of this patient’s biopsy?

a. Pedicels

b. Filtration slits

c. Slit diaphragms

d. Glomerular basement membranes

e. Fenestrated endothelium of glomerular capillaries

Rationale:

COL4A5 is a gene mutation that causes a changes to a protein called collagen. Collagen was known important to the structure and function of the kidney. This changes to protein can lead on hearing loss and eye problem. This gene is known to be present to those patients who is suffering Alport syndrome. Alport syndrome is a disease that damages the blood vessels inside the kidney that result to loss of kidney function. It is known to cause hematuria by the attacking the glomerular basement membrane. Glomerular basement membrane is a unique thick basement membrane that keeps kidney’s filtration barrier. The glomerular basement membrane is made up of podocyte and endothelial cell basement membranes throughout glomerulogenesis.

Answer 1

Question no 1

Option e is the answer as the blood the us reaching the renal artery nice into the kidney through the segmental artery which then turns into the interlobar artery in the kidney. And the arcurate artery receive it's blood from the interlobar artery and the next the blood moves into the interlobular artery . After the blood reach the interlobular artery from the arcurate artery it will reach the afferent arterioles which undergo the filtration process .

Option a is wrong as after going through the interlobular artery only it will reach the afferent arterioles so it is wrong

Option b is Wrong as the blood goes into interlobular artery from arcurate artery and not into efferent Arterioles as the efferent Arterioles will only come after reaching the afferent arterioles.

Option c is wrong as glomerular capillary lie after afferent arterioles and not after the arcurate artery

Option d is wrong as interlobar artery lie before the arcurate artery