RENAL DISEASE

 

RENNAL DISEASES 

Applied anatomy 

Urinary system includes 

 1. Kidneys

 2. Ureters 

 3. Urinary bladder 

 4. Urethra 

Kidneys :

    The kidney are a pair of excretory organs situated on the posterior abdominal wall , one on each side of the vertebral column, behind the peritoneum .They remove waste products of metabolism and excess of water and salts from the blood 🩸 and maintain its pH . The kidneys are been shaped. The normal kidneys measures about 12*6*3 cm and weight is about 130gm.The right kidney is slightly lower than the left due to the bulk of right lobe of the liver .

Structure of kidneys 

The internal structure of the kidneys is displayed when the organ is sectioned in longitudinally:

(I) Fibrous capsule : surrounding the kidneys 

(ii) cortex: outer , reddish brown area , immediately below the capsule and outside the pyramid 

Medulla : Inner , pale are consisting of renal pyramids.

The hilum is the concave medical border of the kidney where the renal veins , artery, lymphatic vessels , Ureters , and nerves are located .

The renal pelvis is the funnel - shaped structure, which acts as a receptacle for the urine formed by the kidney . It has a number of distal branches called calyces , each of which surrounds the apex of a renal pyramid .

The histological and functional unit of the kidney is a nephrons in each kidney . Each nephron consists of closed tubule at one end the other end opening into a collecting tubule . The closed end is indented to form the cup - shaped glomerular capsule ( Bowman ‘s capsule),which almost completely encloses a network of arterial capillaries ( the glomerulus) . The tubular part of a nephron is about 3 cm long and has 3 parts :

 1. Proximal convoluted tubule 

 2. Loop of Henle ( medullary loop)

 3. Distal convoluted tubule, leading into a collecting duct.

        The collecting ducts unite , forming larger ducts that empty into the minor calyces .

Function of kidneys:

 1. Formation and secretion of urine .

 2. Production and secretion of erythropoietin. 

 3. Production and secretion of renin.

 4. Maintenance of electrolytes and pH.

Blood 🩸 supply : 

 • Renal arteries and veins 

Diseases of kidney

 • Glomerulonephritis 

 • Nephrotic syndrome 

 • Acute pyelonephritis

 • Acute renal failure 

 • Chronic renal failure 

 • Renal calculi 

 • Urinary tract infection 

 • Ureteritis

 • Cystitis 

 • Retention of urine 

 • Benign and malignant tumor of kidneys and urinary bladders.

Ureters 

The ureters are a pair of narrow ; thick - walled muscular tubes which convey urine from the renal pelvis to urinary bladder . Each ureter is about 25cm long with 3 mm in diameter. The ureters are slightly constricted at 3 places which are the places of lodgment of clots or stones .

i. Pelvic ureteral junction 

ii. Brim of the lesser pelvis 

iii. Within the bladder wall 

Blood supply 

 • upper part - Renal artery is branch of abdominal artery 

 • Middle part - Direct from aorta

 • Pelvic part - inferior and superior vesicles and uterine arteries ( in female ) 

Renal colic 

  

Severe pain due to a ureteric stone or clots which causes spasm of ureter . The pain starts in the lion and radiates down to the groin ,the scrotum ( male ) and the labia majus ( female) and the inner side of the thigh . This pain is referred to the cutaneous area innervated by segments, mainly T11 to L2 which also supply the ureter .

Urinary bladder 

The urinary bladder is a muscular hollow structure, which lies in the pelvic cavity. It acts as a reservoir for urine and varies size and position, depending on the amount of urine it contains . The mean capacity of the bladder in an adult male is 220 ml , varying from 120 to 320 ml. Filling beyond 220 ml causes a desire to micturate , and the bladder is usually emptied . When filled to about 250 ml to 300 ml . Filling up to 500 ml may be tolerated, but beyond this amount becomes painful .

            Referred pain is felt in the lower parts of the anterior abdominal wall , perineum and penis .

Blood supply : 

 • superior and inferior vesicles arteries 

Urethra 

The urethra is a muscular tubular structure extends from the urinary bladder to the exterior at the external urethral orifice .The male urethra is 18-20cm long . The male urethra has 3 parts 

 1. The posterior part passes through the prostate (3 cm)

 2. The membranous part is surrounded by the sphincter urethrae ( 1.5-2cm)

 3. The spongy part( penile ) passes through the bulb and corpus spongiosum of the penis .

The femal urethra is about 4 cm long , passing from the neck of the bladder at the lower angle of the trigone to the external urethral meatus , which is in front of the vaginal orifice and 2.5 cm behind the clitoris .

With the urethra being such a short straight tube , catheterization in the female is simple compared with the male , but it must be remembered that in the later stages of pregnancy 🤰 the urethra may be considerably stretched so that the catheter may have to be passed for more than twice the normal distance. 

Common investigations for Renal Disease :

 1. Urine for : protein , sugar , RBCs , WBCs , ketone bodies, casts .

 2. 24 hour urine for protein 

 3. Intravenous urography ( IVU).

 4. Ategrade and retro grade pyelography .

 5. CT scan 

 6. Renal angiography 

 7. Renal biopsy.

 8. USG abdomen and pelvis .

 9. KUB X - ray to rule out calculi .

 10. Biochemical tests : Sugars , urea , cretini-e , sodium, potassium, calcium, phosphorus, uric acid , protein.

 11. Blood test for :TC, DC, ESR,Hb% peripheral smears .

 12. Cystoscopy 

 13. Ureteroscope

 14. MRI ( magnetic resonance image ).

 15. Immunological 

 ⁃ ANA(anti nuclear antibody )

 ⁃ LE cells 

 ⁃ Anti DNA antibody 

 ⁃ Serum complement level .