Main parts of the urinary system are: a) kidneys b) ureters c) the urinary bladder d) the urethra...

Main parts of the urinary system are:a) kidneys b) ureters c) the urinary

bladder d) the urethra

The location of the kidneys* The two kidneys lie against the muscles of

the back in the upper abdomen. * Each kidney is enclosed in a membranous

capsule. * The kidneys, as well as the ureters, lie

behind the peritoneum, in the retro peritoneal space.

Functions of the kidneys are:

•Regulation of the volume of the extra cellular fluids and PH of the organism

•Excretion of the toxic substances or the waste products of the human metabolism that should be removed from the human body

•Production of renin, an enzyme which is important in the regulation of blood pressure.

•Production of the hormone erythropoetine, which stimulates the production of red blood cells in red bone marrow (when the kidneys do not get enough oxygen).

Development of the kidneys:

The whole urinary system has 3 stages of the development:

*The 1st stage is called pronephros (the 3rd week) - has dorsal-lateral caudal position, has no excretory function.*The 2nd stage is called mesonephros (the 4th week of gestation) - develops as a tubular part up to collecting tubules entering cloacae.*The 3rd stage is called metanephros - is the final kidney and develops from two parts: mesoderm and the mesonephros.

•The budging of mesonephrotic duct grows and differentiates into uretras, pelvis, calyxes and collecting tubules.

•Along with the development of the tubules the mesoderm accumulates and regroups around them forming the capsule of the glomeruli.

•The parietal cells multiply more rapidly than the visceral.

•Capillary system enters Bowman’s capsule forming future glomeruli of the kidney.

Development of the kidneys (continued):

Development of the kidneys (continued):

Simultaneously the tubular part of the nephron develops later being fused to the collecting ducts of the mesonephros. *The formation of the final kidney goes on in the pelvic part of the body.

Development of the kidneys (continued):

•With development of the urinary organs they ascend to the lumbar part locating retroperitoneally.

•Simultaneously the rotation of the kidney starts and at the final position they are bean - shaped and their convex margin is faced laterally.

•The abnormal development of the urinary system results in the formation of the different malformations: cystic kidney, renal agenesis or aplasia, dislocations, S – like kidney, L – like kidney horseshoe kidney and so on.

•Placenta plays a role of kidney before the full development of the urinary tract is finished.

Development of the kidneys (continued):

*Relatively big size*Lower position of the kidney up to the 2 years.*At the age of 5 years and in older children the structure of

the kidney is similar to those of adults.

The anatomical and morphological peculiarities of the kidneys:

–Nephron is not fully differentiated before 2 year. Thus the Bowmen capsules visceral layer is covered by the cubical epithelial cells which make the filtration difficult.

–At the age of 2 - 4 years the cubical epithelium exists only in the small foci of the kidney, mainly it is replaced by the plane one.

The anatomical and morphological peculiarities of the kidneys (continued):

–Relatively small size of renal glomeruli before 2 year results in lower filtration surface.

–The renal tubules are short, and their lumen is narrower.

–The loop of Henle is shorter and the lumen is narrower than in adults so the re-absorption of the primary urine is restricted.

The anatomical and morphological peculiarities of the kidneys (continued):

The anatomical and morphological peculiarities of the kidneys (continued):

–Lobular surface. By the 2nd year the lobularity of kidney surface disappears.

–Cortex is not fully developed

–Hyper motility during respiration

–The renal pelvis is developed fully, but the muscular and elastic tissue is not completely formed.

*The urinary lymphoid system has a connection to the GIT lymphoid system which contributes to the contamination of the urinary system by the GIT microbes.

*The urethras have bigger diameter, they are relatively longer so they form a folders and loops.

The anatomical and morphological peculiarities of the kidneys (continued):

–The urinary bladder has a poorly developed muscular layer and elastic tissue. Conversely the mucous is fully developed and well vascularized.

–The urinary bladder in children is smaller, has a higher position than the pubic symphysis, which makes the palpation and the puncture easier.

The anatomical and morphological peculiarities of the kidneys (continued):

The anatomical and morphological peculiarities of the kidneys (continued):

–the position of urinary bladder is higher

–The urinary bladder has a poorly developed muscular layer and elastic tissue. Conversely the mucous is fully developed and well vascularized.

–The urinary bladder in children is smaller, has a higher position than the pubic symphysis, which makes the palpation and the puncture easier.

–The urethra is shorter, has poorly developed elastic fibers and connective tissue.

The anatomical and morphological peculiarities of the kidneys (continued):

*There are sexual differences in the length and the еight of the urethra. Urethra length is 5 to 6 cm in boys, 1 - 2 cm in girls. So due to the shorter urethra in girls the possibility of the retrograde infection increases.

*The volume of urinary bladder in newborn is 50 ml, at age of 1 year- 200ml, and in adults it is 400ml.

The anatomical and morphological peculiarities of the kidneys (continued):

The daily amount of the urine in 1 month children – 200-250ml, in 1 year – 600ml.

The daily amount of the urine in children at age 1-10 years can be counted by the following formula

600+100(n-1)

n – age in years.

The anatomical and morphological peculiarities of the kidneys (continued):

–There are differences in the chemical content and the osmolarity of the urine which depend on the age. The osmolarity of the urine is lower.

–The content of the uric acid in the final urine is higher at the 3-4th day of the life often resulting in kidney infarctions.

The anatomical and morphological peculiarities of the kidneys (continued):

*The children’s kidneys are not capable to excrete the whole necessary amount of water

*Creatin clearance is lower as well as the whole glomerular filtration.

Functional peculiarities of the urinary tract in children (continued):

Functional peculiarities of the urinary tract in children (continued):

–The reabsorbtion of the glucose is decreased, so the glucosuria is one of the physiological peculiarities of the childhood period.

–The reabsorbtion of the sodium is higher which results in the accumulation of the water in the circulatory system.

Functional peculiarities of the urinary tract in children (continued):

–Excretion of the acidic radicals is lower so the kidney ability to regulate the alkaline – basic balance is much more lower.

–Excretion of the ammonia is lower

–The secretion of some substances, like penicillin or para-aminohippuric acid, is decreased.

–The number of urination in newborn- 20-25, in infant- 15.

Assessment of the urinary system

Anamnesis:

-Complaints,

-History of the disease

-Family history.

The main complaints are:

•Pains on urination (sharp or burning pains/colic on urination)

•Back pain

•Headaches

•Changing of the urine color and /or the amount of daily urine output

•Edema

•Thirst

*The presence of preceded diseases (during the last month), like tonsillitis, scarlet fever, acute respiratory infections, allergic reactions, vaccinations, etc., which have diagnostic value.*Family history of the urinary tract disorders, hearing loss

(Alport syndrome), arterial hypertension, urinary tract malformations.

It is important to clarify:

–Abnormal pregnancy: gestosis, infections (chlamydeous, mycoplasma, cytomegalovirus etc).

–Possibility of nephrotoxic impacts: bottle feeding, drug taking, poisonings, other chemical substances

It is important to clarify (continued):

It is important to clarify (continued):

–To establish the presence of such specific symptoms as:

–Dysuria - frequent and painful urination, imperative urge to void urination, etc

It is important to clarify (continued):

–Low back pain and/or abdominal pain

–Edema (slight edema or puffiness of eyelids/lower extremities; general edema/anasarka )

–Changes in urinalysis (proteinuria, hematuria, leucocyturia etc.)

Inspection:

*Skin color changes (can be indicative for the different diseases):

-pallor – in nephritis - peripheral vasoconstriction, edemas, anemia

-pallor with grayish shade – in pyelonephritis-dryness and pilling of the skin in case of chronic renal failure

*Edema – expressiveness (slight/general) / localization (in the facial region, extremities, abdominal cavity

•Heart and vascular system: measurement of the arterial blood pressure, of the cardiac left border enlargement, accentuated S1 cardiac tone on the apex and S2 cardiac tone on the aorta.

•Signs of dysembriogenesis

Inspection (continued):

Palpation of the kidneys :

*Is possible only in childhood and mainly in thin children with small weight (more frequent right kidney).

*Positive result of palpation of the kidney in older children indicates increase of the sizes of the kidneys (tumor, hydronephrosis, polycystosis, etc.) or kidneys displace.

Percussion of the kidneys :

•Is done in the lumbar area (in the corner between low rib and vertebral column).

•Positive Pasternatsky (from one or two side the patient feels pain) is indicative for the kidney inflammatory disorders.

Laboratory examination:

*General urine analysis evaluation includes:

*the physical and the chemical characteristics ( the transparency, color, odor, density)

*microscopy of the urine for determination the cell content – epithelial cells, leucocytes, erythrocytes, cylinders, salt.

Laboratory examination (continued):

The transparency: the healthy urine is transparent.

*The clouding can be caused by the increased amount of the salts, cells, mucous.

Color is yellowish or amber.

Color can be changed to:

•reddish – hematuria, amidopyrinum intake, beet in the diet

•dark red – hemoglobinuria in hemolytic anemias, noncompatable blood transfusion

•dark brown – alcaptonuria, mechanical jaundice

•yellowish –intake of the santonin

•milky white – chyluria in case of lymphostasis

•beer color – hepatitis

Laboratory examination (continued):

Odor can be changed and be like

*acetone smell - ketonurias when diabetes mellitus or acetonemic vomiting

*mouse smell - phenilketonurias

Laboratory examination (continued):

Sugar is absent in general in urine and its appearance can be due to enzyme deficiencies like disaccharides insufficiency, tubulopathies, diabetes mellitus.

Epithelial cells, leucocytes exists in urine constantly:

•epithelial cells no more than 9-10 cells within eyeside

•leucocytes no more than 4-6 cells within eyeside

Laboratory examination (continued):

*Leucocyturia characteristic for inflammation – pyelonephritis.

*Presence of the erythrocytes is almost always connected with existing of the pathological process (exception - rare cases transitory erythrocyteuria due to heavy physical exertion).

*Hematuria is an excessive loss of the erythrocytes through the kidney in comparison with the age normal values. Can be observed in glomerulopathies, hemolytic anemia, renal bleedings, renal tuberculosis.

Laboratory examination (continued):

Cellular content of the urine

* Daily amount of leucocytes (2.5106 ), erythrocytes (8105 ), cylinders – 2000 (Addis – Kakovski test)

* Amount of leucocytes (2000 cells), erythrocytes (1000 cells) in 1 ml of the urine. (Nechiporenko test), cylinders – not more 250 in 1 ml

Protein can be found in healthy urine in amount:*general analysis – 0.033g/l*daily amount – 0.03 -0.150 g/ daily

Proteinuria can be as a sign of:*glomerular damage: inflammatory or noniflammatory glomerulopathy*cellular origin, when there is erythrocyteuria, leucocyteuria.*tubular – chronic pyelonephritis, interstitial nephritis, heavy metal poisoning

Proteinuria can be:

•Mild – 0.15-1,0 g/daily;

•Moderate – 1,0 -3.0 g/daily;

•Severe – more than 3 g/daily

Functional methods of the urine examination:

1.Concentrating test – Zymnitskii test:

* Collect the urine each 3 hours. The first 4 portions of the urine make the daily diuresis, the last 4 portions make nocturnal diuresis. The daily one is 2/3 or ¾ of the whole amount of the urine. If the nocturnal portion is more nicturia is present.

* The normal daily ranges between the maximal and minimal urine density are 8-10.

Zymnitskii test (continued):

•Density of the urine is compared with the plasma density:

•The density equal to plasma 1010- 1012 is called isostenuria,

•The lower one–is hypostenuria (in chronic renal failure, diabetes insipidus).

2. Urine culture

* Bacteriuria is defined as amount of bacteria more than 100000 in 1 ml of the urine..

* Pyuria is a presence of an excessive leucocyturia and bacteriuria.

* Can be observed in urinary tract infection, pyelonephritis.

3. Glomerular filtration is based on the determination of creatin clearance.

•Normal GF = 100-120ml/min

•Formula to count the amount of creatin excreted is

•C=UV:P where C – creatin filtration, U – creatin amount in the urine

•V- one minute diuresis, P – plasma amount of creatin.

Instrumental methods of examination

1. Ultrasound examination determines kidney position, mobility, size, morphology and reveals the:*Urinary system congenital malformations (renal agenesia, hypoplasia, ectopia, polycystic kidney etc.)*Signs of some acquired diseases (cystitis, carbuncul, secondary hydronephrosis)*Tumors of the urinary organs*Urinary tract stones*Refluxes

Instrumental methods of examination (continued)

2. Mictious cystoureterography determines urinary bladder malformations, tumors, refluxes

3. Cystoscopy – endoscopic examination of the urinary bladder, and using X – ray – contrasts to evaluate the urodynamics.

4. Radioisotopic examination permits to evaluate kidney parenchyma, ureters, urinary bladder, excretory function of the urinary system.

5. Excretory urography is one of the X- ray methods examination of the urinary system using X – ray contrast substances. It helps to reveal *Position and morphology of the collecting part of the urinary system*To evaluate the secretory function*To determine the kidney mobility*Structure and function of the ureters and urinary bladder.

Instrumental methods of examination (continued)

6. Aortography and angiography are roentgenological methods of kidney vessel examination. Indications are: kidney or renal artery trauma, renal arterial hypertension, suspicion of the tumors.

7. MRI (magnetic – resonance investigation) and CT (computer tomography) study the structure of the urinary system on different levels.

Instrumental methods of examination (continued)

Kidney biopsy and histological and immunomorphological examination of the tissue help in confirmation of the diagnosis or

differential diagnosis and are indicated :

*In case of the renal failure of unknown etiology

*To evaluate the condition of the renal graft

*To determine the case of the renal hematuria and proteinuria

*In case of tubulopathy of unknown etiology