The Urinary system
More about the Kidney
Anatomy and Physiology of the Kidney
The kidneys lie along the borders of the Psoas muscles and are therefore obliquely placed. The position of the liver causes the right Kidney to be lower than the left. The Adult Kidney weighs about 150g. The kidneys are supported by the perirenal fat (which is enclosed in the perirenal fascia), the renal vascular pedicle, abdominal muscle tone, and the general bulk of the abdominal viscera. Variations in these factors permit variations in the degree of the renal mobidity. The average descent on inspiration or on assuming the upright position is 4-5cm.
The Adult Ureter is about 30cm long, varying in direct relation to the height of the individual. It follows a rather smooth S curve. Areas of relative narrowing are found
- at the ureteropelvic junction
- where the ureter crosses over the iliac vessels, and
- where it passes through the bladder wall.
The Adult bladder normally has a capacity of 350ml-450ml. Where empty, the Adult bladder lies behind the pubic symphysis and is largely a pelvic organ.
General/Patient note and main urologic symptoms
The Kidneys play a central role in the maintenance of a constant internal environment for body cells in response to cellular catabolism and wide variations of dietary intake. It achieves this by regulating extracellular fluid and solute concentrations by the excretion of salts, water, metabolic waste products and foreign substances. The process involves the production of a plasma Ultrafiltration of 180L per day. This passes down to about 2 million tubules from which essential solutes and water reasbsorbed into the blood and non-essential solutes secreted from the blood into the remaining fluid which becomes the final urine. The other functions of the kidney incude hormone production and the production of glucose by breaking down other non-carbohydrate substrates (gluconeogenesis).
Main Urologic symptoms
Systemic manifestations, local and referre pain (Kidney pain, Pseudorenal pain, ureteral pain, vesical pain, prostatic pain, testicular pain, epididymal pain, back and leg pain), gastrointestinal symptoms of urologic disease, symptoms related to the act of urination (frequency, nocturia and Urgency, burning sensation during urination, symptoms of prostatic obstruction, symptoms of urethral obstruction, incontinence, oliguria and anuria, Pneumaturia, cloudy urine, bloody urine, enuresis (an inability to control urination. Use of the term is usually limited to describing individuals old enough to be expected to exercise such control) ), other objective manifestations (Urethral discharge, skin lesions of the external genitalia, visible or palpable masses, edema, bloody ejaculation, gynecomastia, size of penis in infant or child), complaints related to sexual problems.
Typical renal pain is usually felt as a dull and constant ache in the Costovetebral angle (pix 3, just by the right) just lateral to the sacrospinalis muscle below the 12th rib. This pain often spreads along the subcostal area towards the umbilicus or lower abdominal quadrant. It may be expected in those renal diseases that cause typical pain. Such disease include cancer, chronic pyelonephritis, staghorn calculus, tuberculosis, polycystic Kidney, and hydronephrosis (is distension and dilation of the renal pelvis calyces, usually caused by obstruction of the free flow of urine from the kidney) due to mild ureteral obstruction. The pressure within the renal pelvis is normally close to zero. When this pressure increases because of obstruction or reflux, the pelvis and renal calices dilate. The degree of hydronephrosis that develops depends upon the duration, degree and site of the obstruction. The higher the obstruction, the greater the effect upon Kidney.
Altered Urination can be in the following forms, dysuria, pollakiuria, precipitant urination, frequent urination, urinary difficulty, chronic urinary retention, paradoxical ischuria. In chronic Urinary retention, this may cause little discomfort to the patient even though there is great hesitancy in starting the stream and marked reduction of its force and caliber. Constant dribbling of urine (paradoxic incontinence) may be experienced. It may be likened to water pouring over a dam. Urinay incontinence (Enuresis) can be in various forms such as, true incontinence (free urine outflow without any true cause), stress incontinence (uncontrolled urine outflow due to stress, fear, anxiety), urge incontinence (free and uncontrolled urine outflow when the urge arises), paradoxic incontinence. Strictly speaking, enuresis means bedwetting at night. It is physiologic during the first 2 to 3 years of Life.
As for Acute retention, it is the sudden inability to urinate. The patient experiences increasingly agonizing suprapubic pain associated with severe urgency to urinate and may dribble only small amounts of urine. Oliguria and Anuria may be caused by acute renal failure (due to shock or dehydration), fluid-ion imbalance, or bilateral ureteral obstruction. Proteins in Urine is called Proteinuria. It can be pathologic and Non-pathologic (which is also physiologic or orthostatic). Therefore, proteinuria of any significant degree (2-4 +) is suggestive of 'medical' renal disease (parenchymal involvement). Bacteria in Urine is called bacteriuria. A presumptive diagnosis of bacterial infection may be made on the basis of results of microscopic examination of the urinary sediment.