Age related differences in anatomy and physiology of the renal system (infants)

Question 1

When does the urinary system begin to develop in utero?

Answer 1

The urinary system begins to develop during the 3rd week of gestation.

Question 2

What gene plays a significant role in all stages of kidney development?

Answer 2

gene WT1

Question 3

What develops in stages and continues to develop through the ninth month of gestation?

Answer 3

glomeruli

Question 4

The kidneys development during gestation.

Answer 4

The kidneys ascend to the sacral area around 6 weeks gestation. to the 3rd lumbar area by the 3rd month of gestation. and to the first lumbar area at 9 months of gestation.

Question 5

At birth the kidneys…

Answer 5

occupy a large portion of the posterior abdominal wall.

Question 6

At birth the ureters…

Answer 6

are shorter than an adult

Question 7

all nephrons at birth….

Answer 7

are present at birth and the number does not increase as the infant matures

Question 8

When do the kidneys reach adult size?

Answer 8

The kidneys reach adult size by adolescence and this represents a 5-fold increase in weight from birth.

Question 9

Urine formation in gestation….

Answer 9

Urine formation and excretion begin by the 3rd month of gestation and contributes to the amniotic fluid.

Question 10

At birth the bladder…..

Answer 10

At birth the bladder is close to the abdominal wall and descends into the pelvis with growth.

Question 11

When will a newborn void?

Answer 11

The newborn may not void for 12-24 hours after birth.

Question 12

Immediately after birth renal blood flow and GFR?

Answer 12

increase due to a decrease in vascular resistance and the need to function now that the placenta is detached

Question 13

Renal vascular resistance is? in newborns

Answer 13

Renal vascular resistance is high in newborns and infants because of increased levels of renin. The resistance decreases as the baby ages.

Question 14

When does GFR reach adult levels?

Answer 14

GFR reaches adult levels by age 2

Question 15

Infants vs adult urine…

Answer 15

Infants have a more dilute urine up to age 6 months when compared to adults.

Question 16

Are infants kidneys more or less responsive to ADH?

Answer 16

Their kidneys are less responsive to ADH.

Question 17

Why is urea excretion low in infants?

Answer 17

Urea excretion is low in infants because of a high anabolic state and use of their protein for growth.

Question 18

What results due to the immature tubular system?

Answer 18

The tubular system is immature in infants and this results in a decreased ability to excrete potassium, reabsorb bicarbonate, or buffer hydrogen with ammonia.

Question 19

When does the tubular system mature?

Answer 19

The tubular system matures by the age of 2