Anatomy of the Urinary Tract

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A diagram of the urinary system. The adrenal glands (1) sit on top of the kidneys (2) which are in the lower back. The ureter (3) connects the kidney to the urinary bladder (7) which sits at the base of the pelvis (5). The urethra (8) is a tube from the bladder out of the body. The renal vein (4) and renal artery (5) connect the kidneys to the abdominal aorta and inferior vena cava.
These structures of the human urinary system are present in both males and females.

Source: OpenStax Microbiology
A cross section of a kidney a solid out regions outlines triangular regions labeled lobes. A tubes beginning at the points of each lobe fuse into a single large tube labeled ureter. A close-up of a lobe showing two nephrons feeding into the tube that feeds into the ureter. Nephrons have a bulb at one end labeled glomerulus. This becomes a tube labeled proximal convoluted tubule which becomes the loop of Henle which becomes the distal convoluted tubule which feeds into the collecting duct. From here urine flows to the renal papilla and ureter. Afferent arterioles feed into the glomerulus and efferent arterioles take materials away from the glomerulus. The venule carries blood away.
The kidney contains several lobes, each of which contains millions of nephrons. The nephron is the functional unit of the kidney, filtering the blood and removing water and dissolved compounds. The filtrate first enters the glomerulus and then enters the proximal convoluted tubule. As it passes through the tubule, the filtrate is further modified by osmosis and active transport until it reaches the larger ducts as urine.

Source: OpenStax Microbiology

OpenStax Microbiology

The basic structures of the urinary tract are common in males and females. However, there are unique locations for these structures in females and males, and there is a significant amount of overlap between the urinary and genital structures in males. 

The kidneys carry out the urinary system’s primary functions of filtering the blood and maintaining water and electrolyte balance. The kidneys are composed of millions of filtration units called nephrons. Each nephron is in intimate contact with blood through a specialized capillary bed called the glomerulus (plural glomeruli). Fluids, electrolytes, and molecules from the blood pass from the glomerulus into the nephron, creating the filtrate that becomes urine. Urine that collects in each kidney empties through a ureter and drains to the urinary bladder, which stores urine. Urine is released from the bladder to the urethra, which transports it to be excreted from the body through the urinary meatus, the opening of the urethra.


Parker, N., Schneegurt, M., Thi Tu, A.-H., Forster, B. M., & Lister, P. (n.d.). Microbiology. Houston, Texas: OpenStax. Access for free at: