RENAL + UROGENITAL DEV'T. Flashcards
The urogenital ridge is derived from the…
Intermediate mesoderm, located along the posterior abdominal wall.
The lateral plate mesoderm differentiates into what two types of mesoderm?
The parietal (somatic) which forms the lateral folds of the body cavity and the visceral (splanchnic) which forms the walls of the gut tube.
Define the cloaca and it’s significance.
The cloaca is an embryonic membrane where external genitalia forms alongside it (in the perineum)
Describe the functions and significance of the kidneys.
Kidneys are located in the lumbar region behind ribs 10-12. They filter 180 liters of blood per day to empty 1-2 liters of urine into the bladder via the ureters. They are primary retroperitoneal organs that play a role in acid-base balance and BP regulation through hormones.
List the layers of the kidney from superficial to deep. Include the collecting portion.
Outer cortex > medullary region > papilla > minor calyx > major calyx > renal pelvis > ureter > urinary bladder.
Compare and contrast nephrons from collecting tubules.
Nephrons are the functional unit of filtration for the kidney in the medullary region. Collecting tubules transport the urine to empty it into the calyxes and eventually into the ureters.
Define the SMA “Nutcracker” Syndrome.
An enlarged SMA or aneurysm of the nearby aorta can compress the left renal vein, 3rd part of duodenum and or the pancreas. This is associated with a dilated left gonadal vein since the backflow is from the left renal vein.
Where do kidney stones occur and what kind of pain can be felt with them?
Kidney stones can occur at constriction points such as the ureteropelvic junction, the pelvic brim and the ureterovesicular junction. These can be felt as low loin-to-groin colic pain as the smooth muscle squeezes to move the stone periodically.
Describe the path of blood flow for the supply to the kidney.
The renal artery gets off at L1/L2 > multiple segmental arteries > arcuate arteries (@ corticomedullary junctions) > interlobar arteries > afferent arterioles > glomeruli.
What are the components of uriniferous tubules?
Nephrons (metanephros) in the renal cortex and collecting tubules (ureteric buds) in the renal medulla are the 2 parts of these tubules.
Define the pronephros, where it is located and its purpose in the embryo.
The pronephros is the anterior portion of the nephrogenic ridge @ the cervical region. It is non-function and regresses after week 4.
Define the mesonephros, where it is located and its function in the embryo.
The mesonephros is a temporary portion of the nephrogenic ridge located at the thoracic-lumbar region. It was briefly functional but regressed a little after. It is vestigial in females but becomes efferent tubules in males.
Define the mesonephric duct and its components.
The mesonephric duct is a specialized part of the mesonephros that gives rise to the ureteric bud. It is composed of the male internal genital system, the trigone (caudal end) that will incorporate into the posterior bladder, and the ureteric bud which forms parts of the collecting system.
Define the metanephros, its location and function.
The metanephros is the caudal portion of the nephrogenic ridge that is the PERMANENT filter for the embryo. It is located at the sacral-pelvis region and later forms the renal cortex (filtering system) of the kidney. It is also known as the “definitive kidney”.
Describe the process of reciprocal induction in the formation of the kidneys.
Ureteric bud and metanephric caps tell each other what to do as the buds grown into the caps. Ureteric buds cause the metanephric caps to elongate and differentiate into convoluted tubules. Whereas, these buds themselves become future collecting tubules as they elongate too.
The right gonadal vein drains into the ______; whereas the left gonadal vein drains into the _______ which drains into the ______.
Right gonadal vein > IVC;
Left gonadal vein > Left renal vein > IVC
The embryonic __________ makes up the filtering portion of the kidney which is composed of _______ (the kidney functional unit). The embryonic _______ makes up the collecting portion of the kidney, which make future _______.
Metanephros, Nephrons;
Ureteric bud, Collecting ducts
The mesonephric duct becomes what 3 components?
- Ureteric bud = future collecting tubules of kidney
- Wolffish duct (male) = internal effluent tubes
- Trigone = caudal end that becomes the posterior bladder
Polyhydramnios involves _____ amniotic fluid in the womb that results from ________ swallowing. In the developing fetus this indicates: _________ or ___________.
A lot of amniotic fluid;
impaired (too little swallowing);
Duodenal atresia or Anencephaly
Oligohydramnios features _________ amniotic fluid in the womb from a ______ of urine production. This indicates a lethal congenital defect known as ______.
Too little amniotic fluid;
Lack of urine production;
Bilateral Reynaldo agenesis (not viable)
Define Potter’s Sequence.
A syndrome of congenital defects consisting of:
Pulmonary hypoplasia, Oligohydramnios, Twisted face, Twisted skin, Extremity deformities, Renal agenesis (bilateral)
Describe what causes an Ectopic kidney.
As the kidneys ascend the inferior poles fuse together leading to a horseshoe shaped kidney that is stuck at the inferior mesenteric artery. The kidneys remain in the pelvis instead of at the L4/5 vertebral levels.
As the _________ ducts fold in to become integrated in the posterior bladder wall, this becomes the embryonic _________ and _________.
Mesonephric ducts;
Trigone and Ureteric buds
What 2 features of the bladder prevents a backflow of urine into the ureters?
- Oblique angle of the ureters as they enter the bladder
2. Shunts at the ureterovesical junction
