Histology - Urinary System

Front 1

1.What are the components of the nephron.

Back 1

The nephron includes: Renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule. Of all these, just the loop of Henle is a medullar structure while the rest reside in the renal cortex.

Front 2

1.What are the differences between the nephron and the uriniferous tubule.

Back 2

The nephron plus the collecting tubule and collecting duct makes the uriniferous tubule (anatomofunctional unit of the kidney).

Front 3

1.What is the specific function of the juxtamedular nephrons?

Back 3

Most nephrons are cortical, and the juxtamedular ones, although less abundant, contribute with most of the urine concentration.

Front 4

1.The _____________ create the visceral layer of the Bowman capsule, and their secondary processes known as ______________ define the filtration slits where filtration actually happens.

Back 4

The cells of the visceral layer of the Bowman capsule, known as podocytes, have finger-like cellular projections known as pedicels, which intertwine with the ones of the neighboring cell. Between the pedicels the filtration slits are created.

Front 5

1.Mention in order the components of the filtration barrier.

Back 5

The filtration barrier is made by:
Endothelial cells
Fused basal laminae (that is, the basal lamina of the podocytes fused with the basal lamina of the capillary vessel).
Podocytes

Front 6

1.Afferent arterioles branch creating the _____________ and they join to create the _______________ that branches again to create _______________ that finally join to create venules.

Back 6

Arterial circulation in the kidney

Interlobar arteries – arcuate arteries – interlobular arteries – afferent arterioles – glomerulus – efferent arterioles – intertubular cortical and medullar capillaries (interstitial capillaries) - venules

Front 7

1.What type of capillary vessels is found in the glomerulus?

Back 7

Efferent arterioles

Front 8

1.What are mesangial cells?

Back 8

Mesangial cells thrive mostly inside the glomerulus. They modify the diameter of the glomerular capillaries and may act as macrophages.

Front 9

1.The _________________ tubule is the most abundant tubular structure in the cortex, it has a remarkable ______________________ activity, and has as function the __________________ of macromolecules.

Back 9

Proximal tubule
1.Most abundant tubular structure in the renal cortex
2.Abundance of mitochondriae, microvilli and basal infoldings. Activity of acid phosphatase.
Function: reabsorption of macromolecules.

Front 10

1.Mention the functions of the loop of Henle.

Back 10

Mostly a medullar structure
Function: Water and salt are reabsorbed. Most of the gradient of hypertonicity (urine concentration) is acquired here

Front 11

1.What major differences both morphologically and functionally the distal convoluted tubule has, if compared to the proximal convoluted tubule?

Back 11

Distal tubule
1.Better defined lumen and cytoplasm than the proximal tubule
2.Function: water is reabsorbed. Some substances are excreted into the urine

Front 12

1.What are the components of the juxtaglomerular apparatus?

Back 12

Juxtaglomerular cells: Modified smooth muscle cells that secrete renin.
Macula densa: Specialized portion of the distal tubule facing the vascular pole of the renal corpuscle.
Pole cushion (aka polkissen or lacis cells): Extramesangial cells at the vascular pole of the renal corpuscle.

Front 13

1.What is the macula densa?

Back 13

Macula densa: Specialized portion of the distal tubule facing the vascular pole of the renal corpuscle.

Front 14

1.What is the pole cushion?

Back 14

Pole cushion (aka polkissen or lacis cells): Extramesangial cells at the vascular pole of the renal corpuscl

Front 15

1.What is renin and what are its functions?

Back 15

Enzyme that regulates the body's overall arterial blood pressure

Front 16

1.What is the function of the interstitial cells?

Back 16

Between the tubules, these cells respond to low concentrations of oxygen. releasing erythropoietin, whose action is to increase the circulating erythrocytes.

Front 17

1.What parts make the excretory portion of the urinary system?

Back 17

Excretory portion (ureter, bladder, urethra)

Front 18

1.What epithelium is found in the excretory portion of the urinary system?

Back 18

All they have the highly elastic transitional epithelium (urothelium).

Front 19

1.What is the disposition of the muscularis in the ureter?

Back 19

1.Muscularis: Inner layer is longitudinal, outer layer is circular (contrary to what we had in the digestive tract)
Third layer, outer and longitudinal, confined to the lower third

Front 20

1.What is the disposition of the muscularis in the urinary bladder?

Back 20

Muscularis: three layers (outer and inner longitudinal; middle circular)

Front 21

1.Mention the most outstanding differences between the male and female urethra.

Back 21

Length, three epithlia in male, 2 in female, female is prone to infection

Front 22

1.What is the lamina propria of the male urethra.

Back 22

Lamina propria at the penis: corpus spongiousum

Front 23

1.What are the Littré glands?

Back 23

Also at the penile urethra: Littré glands (secrete mucus)

Front 24

1.What characteristic makes the female urethra more prone to infections?

Back 24

length