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Science*---------Q�

Nephrons - the filtration Proximal Collecting
unzts ofth kidn tubule duct system
Links Bowman's Although not
ephrons are the units which filter all blood that passes through the kidneys. capsule and the loop technically part of the
N There are around a m1!11on 1n each kidney, s1tuated in the renal medulla's of Henle, and will nephron, this collects
pyramid structures. As well as filtering waste, nephrons regulate water and selectively reabsorb all waste product
mineral salt by recirculating what is needed and excreting the rest. minerals from the filtered by the
filtrate produced by nephrons and
Bowman's capsule. facilitates its removal
from the kidneys.

Glomerulus
High pressure in the
glomerulus, caused
by it draining into an
arteriole instead of
a venule, forces
fluids and soluble
materials out of the
capillary and into
Bowman's capsule.
Bowman's
capsule
Also known as the
glomerular capsule,
this filters the fluid
that has been
expelled from the
glomerulus. Resulting
filtrate is passed
along the nephron
and will eventually
make up urine.
Distal
convoluted
tubule
Partly responsible for
the regulation of
minerals in the blood,
linking to the
collecting duct
system. Unwanted
minerals are excreted
from the nephron.

What is urine and
This artery supplies the
kidney with blood. The what is it made of?
blood travels through
this, into arterioles as
you travel into the rine is made up of a range of 94%water
kidney, until the blood U organic compounds such as
reaches the glomerulus. proteins and hormones,
inorganic salts and numerous
metabolites. These by-products
Renal vein are often rich in nitrogen and
need to be removed from the
This removes blood
that has been filtered blood stream through urination.
from the kidney. The pH-level of urine is typically
around neutral (pH7) but varies
depending on diet, hydration
Loop of Henle Made up of three parts, the proximal levels and physical fitness. The
colour of urine is also determined
The loop of Henle controls the mineral and tubule, the loop of Henle and the distal by these factors, with
water concentration levels within the kidney convoluted tubule. They remove waste dark-yellow urine indicating
to aid filtration of fluids as necessary. It also and reabsorb minerals from the filtrate dehydration and greenish urine
controls urine concentration. passed on from Bowman's capsule. being indicative of excessive 6% other organic
asparagus consumption. compounds
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