Urinary System II

Question 1

How does metenephros position change during differentiaion?

Answer 1

Changes from pelvic to the lumbar region

Question 2

With respect to the degenerating mesonephros, where is the definitive kidney located?

Answer 2

The definitive kidney occupies the position dorsal to the degenerating mesonephros

Question 3

Explain the migration of the right kidney in domestic animals

Answer 3

With the exception of pigs, the right kidney in domestic animals migrate more cranially than the left kidney

-Left is last and lagging

Question 4

With development of nephron and collecting duct system how is the kidney organized?

Answer 4

Into outer cortical and inner medullary regions

Question 5

Parts of the cortex

Answer 5

Renal Corpuscles

Proximal and distal convuluted tubules

Question 6

Parts of medulla

Answer 6

Loops of Henle

Collecting Ducts

Question 7

What leads to the term Medullary Pyramid?

Answer 7

Conical arrangement of loops of Henle and collecting ducts

Question 8

What is the base of the pyramid covered by?

Answer 8

The base of the pyramid is covered by the cortex of the kidney

Question 9

What is a renal Lobe?

Answer 9

A medullary pyramid with cortical covering

Question 10

Explain the topography of the pyramid

Answer 10

Base of the pyramid is covered by the cortex of the kidney and the apex as a papilla projecting into the pelvis of the kidney

Question 11

What are the variations of kidney anatomy between species a result of?

Answer 11

Differences in the branching of the ureteric bud and arrangement of nephrons associated with these branches

Question 12

In early embryo, caudal end of hindgut terminates in an endodermally lined chamber known as?

Answer 12

The cloaca

Question 13

What closes the cloaca?

Answer 13

Cloacal membrane

Question 14

What type of tissue is found between the hindgut and base of the allantois, and what is it called?

Answer 14

Mesodermal tissue called the urorectal septum is found between the hindgut and base of the allantois

Question 15

What occurs as development continues?

Answer 15

As development continues, the septum grows towards cloacal membrane dividing cloaca into rectum and urogenital sinus

Question 16

Once partitioned, what is the cloacal membrane now split into?

Answer 16

Anal and urogenital membranes

Question 17

What does the bladder develop from and what does this follow?

Answer 17

Bladder develops from pelvic region fo urogenital sinus (following cloacal partitioning)

Question 18

What does the more caudal part of the urogenital sinus develop into?

Answer 18

Urethra

Question 19

What is the urogential sinus continuous with?

Answer 19

The allantois

Question 20

What is different about the bladder from the rest of the urinary system?

Answer 20

Bladder is endodermally derived, the rest of the urinary system is derived from the intermediate mesoderm

Question 21

Explain the incorporation of the terminal parts of the mesonephric and ureteric ducts into the bladder

Answer 21

As bladder grows it incorporate the terminal parts of the mesonephric and ureteric ducts

Each duct system though develops own separate opening into developing bladder

Mesonephric ducts are initially anterior to the ureteric buds

Positions gradually shift so ureteric buds finally open into bladder laterally and anterior to the mesonephric ducts

A triangular area in the dorsal wall of the bladder called the trigone marks the region of the mesonephric duct and ureteric bud incorporation

Question 22

What is renal agenesis?

Answer 22

Complete absence of one (unilateral) or both (bilateral) kidneys.

Question 23

What can renal agenesis be associated with?

Answer 23

Absence of ureter

Question 24

What is the most commone congenial kidney condition in pigs?

Answer 24

Unilateral renal agenesis

Question 25

What is renal agenesis a result of?

Answer 25

THe failure of the development of one or both ureteric buds - so there is no induction of the metanephric mass to form renal tubules

Question 26

What is renal hypoplasia?

Answer 26

Substantially small kidneys due to immature glomeruli and tubules. Unilateral and bilateral forms

Question 27

What is the most common renal anomaly in many breeds of dogs?

Answer 27

Renal hypoplasia

Question 28

How do you treat renal hypoplasia?

Answer 28

Managing associated chronic renal failure

Question 29

What are the two migration defects of kidney?

Answer 29

Most common form leaves a kidney in pelvic cavity

Another form is crossed ectopia which is one kidney and its associated ureter on the same side as the other kidney

Question 30

What is horseshoe kidney?

Answer 30

Kidneys become fused at inferior poles. Origin is uncertain.

Question 31

What are polycystic kidney?

Answer 31

Multiple cysts form in the kidney - organs are enlarged

Question 32

What are polycystic kidneys a result of?

Answer 32

Failure of developing nephrons to connect with their collecting ducts

Question 33

What do cysts in polysyctic kidneys arise from?

Answer 33

Accumulation of urine within the nephrons that are isolated from collecting ducts

Question 34

What is an ectopic ureter a result of?

Answer 34

Improper development of the metanephric duct systems

Question 35

What is a patent urachus?

Answer 35

Improper closing of canal which feeds through the umbilicus in fetus, improper closing causes for leakage of urine from naval

Question 36

What are urachal remnants?

Answer 36

Congenital anomaly resulting from imcomplet urachal closure.