Nephron

Dr. Manuela Mai studied medicine at the Universities of Heidelberg and Mannheim. After graduating, she gained clinical experience in gynecology, pathology and clinical pharmacology. She is particularly interested in the broader connections that lead to diseases - also outside of conventional medicine. She completed additional training in classical homeopathy as well as ear and skull acupuncture.

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The nephron is the basic functional building block of the kidney. This is where the urine is formed, which is then excreted. Each kidney contains approximately 1 to 1.4 million nephrons. Each consists of a kidney corpuscle (corpusculum renale, Malpighi corpuscle) and the associated kidney tubules (tubular apparatus). Read everything you need to know about the nephron here!

Nephron: build-up

Each nephron consists of a kidney corpuscle and a tubular apparatus.

Kidney corpuscles

The kidney corpuscle is the first part of the nephron and consists of a tangle of hair vessels (capillaries). This capillary ball is called the glomerulus. It is enclosed in a delicate capsule called the glomerular capsule, or Bowman's capsule.

The glomerulus is a complex tangle of 30 to 40 parallel capillary loops. The blood supply and the outflow are close together and form the vascular pole. This vascular pole always points in the direction of the renal cortex.

The Bowman capsule consists of two leaves. One rests on the capillaries, the other delimits the glomerulus from the environment. There is a gap between the leaves. This is where the primary urine is released.

The capsule opens at the so-called urinary pole into the kidney tubule system. The urinary pole is opposite the vascular pole and points in the direction of the renal medulla.

Renal tubules (tubular apparatus)

The second part of the nephron is the tubular apparatus - a system of thicker and thinner kidney tubules, some of which are arranged in loops. It takes over the primary urine at the urinary pole, concentrating it to about one percent of its volume. It also changes the chemical composition of the primary urine.

The tubular apparatus can be divided into three sections:

Main part (proximal tubule): strongly twisted initial part
Transition piece (intermediate tubule): very thin urinary canal that makes an arch (Henley loop) and merges into the ascending limb
Ascending limb (distal tubule): pulls back to the glomerulus, winds, touches the vascular pole of the kidney corpuscle and opens into a connecting tubule (tubule reuniens).

Several of these connecting tubules finally open into a collecting tube, which encompasses the connecting pieces of about ten nephrons. The collecting tubes lead into the renal pelvis. From there, the urine travels through the ureters into the bladder and then out through the urethra.