Urinary System international university of Kyrgyzstan

Urinary system

1. INTERNATIONAL UNIVERSITY OF KYRGYZSTAN
Lecturer : Malika Kukeshova

3. Some anatomical and structural features of the
components of the urinary system of children are as
follows:

1.1 Kidney /The position of the kidney in young children is lower than in older
children and adults. The lower pole of the kidney is at the level of the IV-V lumbar
vertebrae.
Shape: The kidneys in young children are bean-shaped
Weight: The weight of the kidney increases gradually with age, like a newborn
baby, the kidney weighs about 11 -12g; 6 months 24-25g; 1 year old 36-37g;
Puberty weighs about 115-120g.

4. Structure: The kidney consists of the cortex and the medulla, the ratio between
the cortex and the medulla is 1: 4 in infants, 1: 3 in breastfed infants, and 1: 2 in
adults.

5. The structure of the nephron renal unit is similar to that of an adult, including the
glomerulus, the proximal tubule, the loop of Henle, the distal tubule, the collecting
duct.

6. Ureterus
The ureter in children is
relatively large and long,
so it is easier to bend.
The ureter connects to
the kidney and exits to
form a right angle, while
in older children and
adults, it is an obtuse
angle, so urine is easy.

7. Bladder
The bladder in children is located high above
the pelvis, so when it is filled with urine, the
bladder bridge is easy to feel.
Bladder capacity: This capacity increases with
age.
●Newborns: 30 - 60 ml
●Breastfed babies: 60 - 100 ml
●Children over 5 years old: 100 - 200 ml
●Children over 10 years old: 150 - 350 ml
●Children 15 years old: 200 - 400 ml

8. Urethra
The urethra is the passageway urine from the
bladder out of the body, in young children the
size of the urethra depends on age and sex.
❏Girls: The urethra is wide but short, about
2 - 4 cm. Because of their short and wide
structure, they are more susceptible to
infection upstream than boys.
❏ Boys: The urethra is narrow but about
6-15 cm long.

9. 2. Functional characteristics of the urinary system in
children
1.Glomerular Filtration
2. Reabsorption function
3.Excretion function
4.Endocrine function

10. 1.Glomerular Filtration is the most important function of the
glomerulus and the first step in urine formation. Through the
membrane at the glomerulus, the substances with large molecular
weight are retained and the substances of low weight are eliminated.
The glomerular filtration rate in newborns is still low, only reaching
about 25% of the average value of older children and increasing with
age until about 2-3 years old, the index is similar to that of adults.

11. 2.Reabsorption function of the renal tubules
After the blood is filtered in the glomerulus, the first urine is formed and then followed
by the renal tubules to the renal calyces. However, the composition of the first urine is
full of substances such as amino acids, glucose, salts Ca, Mg, K, Na, Cl... Therefore,
when the first urine passes through the renal tubules, it will be reabsorbed.

❏Children < 2 years old: The renal tubular reabsorption function is still poor, so the
urine density is low. Due to the poor concentration, if the child is dehydrated, the
body is not able to retain water.
❏Children > 2 years old: The reabsorption function is similar to that of adults.

12. Excretion function of renal tubules
Substances that are not necessary for the body, but have a large molecular weight
or have a structure that links molecules together to form a network that will not be
able to be eliminated through the membrane through the filter. They will be
eliminated via secretion in the distal tubule and part of the collecting duct.
The renal tubular secretion
function in children under 2
years old is worse than in
children over 2 years old
and adults.

13. Endocrine function
Endocrine function is an important function of the paraglomerular organization.
The paraglomerular organization works well from the moment the baby is born and
produces two substances:
Erythropoietin: A substance that stimulates the bone marrow to produce red blood
cells.
Renin: Has the effect of activating vasoconstrictor chemicals, causing an increase
in blood pressure.

14. Examination of the child's uropoietic system :

➢anamnesis,(Family history)
➢Perinatal history
➢Personal anamnesis(frequency of urination in 24 hours; fluid intake in 24
hours;The nature of the urine flow,)
➢physical exam,(Inspection,Palpation,Tapotement, Blood pressure)
➢laboratory examination,(bacteriological examination of urine,chemical examination of urine)
➢imaging methods,(Ultrasonography, Ascending pyelography, CT)

15. Palpation
The kidneys and urinary tract are not normally visible or palpable, they are not painful .
Physiologically, the kidneys are felt only in neonatal age (they are relatively large and
relatively higher)

The patient lies on his back; with one hand we lift the kidney at a costvertebral angle,
with the other we palpate the lower pole of the kidney under the rib arch in deep
inspiration,
positive in hydronephrosis, polycystosis, solitary cyst, kidney tumor,

16. Tapotement
It is performed by
striking the fist of
one hand against the
dorsal surface of the
other hand,.
Normally, percussion
should not elicit
tenderness.
can be reliably
assessed only at
preschool age.

17. Laboratory examination
Observing urine:


❖Smell that is strongly ammoniacal may be the sign of infection;
❖Appearance should be straw coloured(соломенно желтый)
❖Children normally void urine five or six times per day depending on their
drinking volumes and environment conditions

18. GLOMERULAR DISEASES
❖Synonyms :
- Glomerulonephritis (GN)
- Glomerulopathy
❖ Definition
- A group of conditions in which glomerular injury occurs

19. Pathogenesis:
Glomerular injury includes several mechanisms:
- Damage by immune complexes
- Damage by autoantibodies
- Cell-mediated immune injury
- Damage by complement and proinflammatory mediators

20. Classification according to etiology
(Gold is used most often to treat rheumatoid arthritis.)
(A substance made from morphine).
is a rare
inherited
disorder that
damages
the tiny
blood
vessels in
the kidneys.

21. Classification according to clinical features
(glomerular syndromes)