Ren 1 - Renal Embryology and Anatomy

Question 1

What does the pronephros becomes?

Answer 1

It disappears at week 4.

Question 2

What does the mesonephros becomes?

Answer 2

Functions as a fetal kidney during the first trimester. Later becomes part of the male genital system.

Question 3

What does the metanephros becomes?

Answer 3

It becomes the adult kidney; appears during the fifth week of gestation.

Question 4

What is the ureteric bud and from what structure does it appear from?

Answer 4

1. It gives rise to the entire collecting system, it appears from the caudal end of the mesonephros.
2. It induces metanephros to differentiate into the renal tubular epithelial structures; into the nephrons.

Question 5

What is Potter sequence?

Answer 5

AKA Potter syndrome:
[POTTER]
-Pulmonary hypoplasia.
-Twisted skin (wrinkled skin).
-Twisted face (facial deformities).
-Extremities (limb deformities).
-Renal agenesis (the cause of Potter sequence).

Question 6

What happens when there are no ureteric buds?

Answer 6

• No collecting system.

- Bilateral renal agenesis: without the ureteric buds to inducing the metanephros to develop into the nephrons.

Question 7

What is a horseshoe kidney?

Answer 7

When the inferior poles of both kidneys fuse, forming a single kidney, in a U shape. As this kidney ascends from the pelvis in development, it gets hung up under the inferior mesenteric artery (IMA) and stay low on the abdomen.

Question 8

Which artery traps the horseshoe kidney?

Answer 8

Inferior mesenteric artery (IMA).

Question 9

Which syndrome is associated with horseshoe kidney?

Answer 9

Turner syndrome.

Question 10

Where in the kidney is the glomerulus found?

Answer 10

In the cortex of the kidney.

Question 11

Through which vessels does blood get into the glomerulus and which vessel leaves the glomerulus?

Answer 11

Blood enters through the (accepts) Afferent arteriole.

Blood leaves through the (emits) Efferent arteriole.

Question 12

What are the layers of the glomerulus layer?

Answer 12

1. Capillary endothelium (it is fenestrated).
2. Basement membrane (negatively charged).
3. Podocyte foot process.

Question 13

Where are the Juxtaglomerular cells located? And where are the macula densa cells at?

Answer 13

It is just between afferent arteriole and distal tubule. The macula densa are on the distal tubule.

Question 14

Which cells make up the Juxtaglomerular apparatus?

Answer 14

1. Juxtaglomerular apparatus.

2. Macula densa.

Question 15

What do Juxtaglomerular cells release? And what does the Macula densa do?

Answer 15

The macula densa senses Sodium levels. The Juxtaglomerular cells to release renin on the command of the densa macula.

Question 16

What are the three things that tells the juxtaglomerular cells to release renin?

Answer 16

1. Beta-adrenergic stimulation.
2. Low sodium in the DCT (under the command of the macula densa.
3. Low pressure in the afferent arteriole.

Question 17

What does Renin do?

Answer 17

It cleaves angiotensinogen into angiotensin I. Then the ACE (Angiotensin converting enzyme) turns angiotensin I into angiotensin II.

Question 18

What does angiotensin II do?

Answer 18

1. Vasoconstrictor (raises BP).

2. Stimulates adrenals to make aldosterone (aldosterone causes sodium and water retention).

Question 19

Where are the glomerulus found in the kidney versus where are the nephrons found in the kidney? Where are the collecting tubules drain into?

Answer 19

• Glomerulus are found in the Cortex.
• Nephrons are found in the Medulla.
• The collecting tubules drain into Medullary pyramids.

Question 20

Where do the ureters merge to?

Answer 20

They run retroperitoneally down towards the bladder at the uretrovesicular junction (UVJ)- a common site for renal stones to get stuck.

Question 21

What is the difference of ureter placement between men and women?

Answer 21

[Water under the bridge]

• On men, they pass under uterine artery (women).
• On women, pass under vas deferens (men).

Question 22

What artery prevents a horseshoe kidney from ascending into the abdomen?

Answer 22

Inferior mesenteri artery (IMA).

Question 23

What fundamental problem creates Potter sequence?

Answer 23

Oligohydramnios.

Question 24

What cell type releases renin?

Answer 24

Juxtaglomerular cells.

Question 25

What are the three primordial structures that gives rise to the kidney?

Answer 25

1. Pronephros.
2. Mesonephros.
3. Metanephros.