Urology deals with diseases and disorders of the male genitourinary tract, the female urinary tract, and the adrenal gland. These systems are illustrated in Figures 1–1 and 1–2.
Anatomy of the male genitourinary tract. The upper and midtracts have urologic function only. The lower tract has both genital and urinary functions.
Relations of kidney, ureters, and bladder (anterior aspect).
Each kidney is capped by an adrenal gland, and both organs are enclosed within Gerota's (perirenal) fascia. Each adrenal weighs about 5 g. The right adrenal is triangular in shape; the left is more rounded and crescentic. Each gland is composed of a cortex, chiefly influenced by the pituitary gland, and a medulla derived from chromaffin tissue (Avisse et al, 2000; O'Donoghue et al, 2010).
Figure 1–2 shows the relation of the adrenals to other organs. The right adrenal lies between the liver and the vena cava. The left adrenal lies close to the aorta and is covered on its lower surface by the pancreas. The spleen lies superior and lateral to it.
The adrenal cortex, which makes up 90% of the mass, is composed of three distinct layers: the outer zona glomerulosa, the middle zona fasciculata, and the inner zona reticularis. The medulla lies centrally and is made up of polyhedral cells containing eosinophilic granular cytoplasm. These chromaffin cells are accompanied by ganglion and small round cells.
Each adrenal receives three arteries: one from the inferior phrenic artery, one from the aorta, and one from the renal artery.
Blood from the right adrenal is drained by a very short vein into the vena cava; the left adrenal vein terminates in the left renal vein.
The lymphatic vessels accompany the suprarenal vein and drain into the lumbar lymph nodes.
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 (Figures 1–2 and 1–3). The adult kidney weighs about 150 g each.
Relations of kidneys (posterior aspect). The dashed lines represent the outline of the kidneys where they are obscured by overlying structures.