Kidney

Kidney :

Pair of excretory organs situated on the posterior abdominal wall, one on each side of the vertebral column, behind the peritoneum.

Function: It removes waste products of metabolism & excess of water & Salt from blood & maintain its pH

External Features:

Shape: bean shaped.

Size: 11cm long, 6cm broad & 3cm thick

Left kidney is little longer and narrower than right kidney

Weight:  150g in male & 135g in female.

It has 2 poles, 2 borders & 2 surfaces

2 Poles - upper and lower pole.

Upper pole is broad and is close contact with corresponding suprarenal gland & lower pole is pointed

2 borders are lateral and medial.

Lateral border is convex, medial part is concave with a depression known as hilum or hilus

2 surfaces are anterior and posterior.

Anterior surface is irregular and posterior surface is flat but its difficult to recognise the surface on behalf of the looking the surface but the best way is to examine the structure present in hilum.

Hilum: from anterior to posterior

1. Renal vein draining in Inferior fans cava

2. Renal Artery branch of Abdominal Aorta

3. The Renal pelvis, which is extended part of ureter.

Location:

It occupy the epigasteric, hypochondriac,lumar & umbilical regions.

Extend from - upper border of T12 vertebra to the centre of the body of L3 vertebra.

Right kidney is lower then the left, left kidney is little nearer to median plane than the right.

The transpyloric plane passes through the upper part of hilus of the right kidney and through lower part if hilus of left kidney.

Relations of the Kidneys:

Common relations

1. Upper pole is related to suprarenal gland & lower pole is 2.5cm above iliac crests.

2. Medial border : suprarenal gland from above & ureter below hilus

3. Posterior surface of both kidneys are related to

  3.1. Diaphragm

  3.2. Medial & lateral arcuate ligament

  3.3. Psoas Major

  3.4. Quadratus lumborum

  3.5. Transversus a dominos

  3.6. Subcostal Vessels

  3.7. Subcostal, iliohypogastric & ilioinguinal nerves.

4. Structures of hilum

Uncommon Relations

         Right kidney.                  left kidney

1. Rt. Suprarenal gland.        Lft. Suprarenal gland

2. Liver.                                  Spleen

3. 2nd part if duodenum.     Stomach

4. Hepatic Flexure of colon  Pancreas

5. Small intestine.                 Splenic vessels

6.                                             Splenic flexure &

                                         descending colom

7.                                            Jejunum

Capsule or Covering of kidney:

1. The fibrous Capsule

This is thin membrane which closely invests the kidney & lines the renal sinus.

2. Periprenal or Perinephric Fat

Layer of adipose tissue lying out side fibrous capsule. The perireanl fascia was originally described as being made up of two seperate layers

2.1. Posterior layer k/a fascia of  Zuckerkandall

2.2. Anterior layer as fadcia of Gerota.

3. Pararenal or Paranephric Body

It consist of a veriable amount of fat lying outside the renal fascia. Most abundant posteriorly & towards the lower lower pole of the kidney. Its fills Paravertebral gutter & forms a cushion for the kidney.

Arterial Supply:

Renal artery arising from abdominal aorta.

Divided in Anterior & posterior artery.

These artery giving further branches gives rise to segmental arteries.

5 segments

1. Apical

2. Upper

3. Middle

4. Lower

5. Posterior

Each segment artery further divide in lobar artery one for each pyramid. Each lobar artery divide into 2-3 interlobar arteries.

Interlobar artery give rise to arcuate arteries which give off interlobular arteries known as end arteries.