Bowman's capsule (or the
Bowman capsule,
capsula glomeruli, or
glomerular capsule) is a cup-like sac at the beginning of the tubular component of a
nephron in the mammalian
kidney that performs the first step in the filtration of blood to form urine. A
glomerulus is enclosed in the sac. Fluids from blood in the glomerulus are collected in the Bowman's capsule (i.e.,
glomerular filtrate) and further processed along the nephron to form
urine. This process is known as
ultrafiltration. The Bowman's capsule is named after
Sir William Bowman, who identified it in 1842.