BLOOD FILTRATION.

Running head: BLOOD FILTRATION
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Title: The Glomerular Filtration

BLOOD FILTRATION
Glomerular filtration, a process by which blood and concentrated metabolic waste are
filtered to form urine, takes place in intricate structures called the glomerulus. Blood filtration
is among the important functions of the kidneys as it helps purify the blood by removing
toxic and metabolic substances from the body. Glomerular filtration only involves filtering
the blood and metabolic but blood components such as plasma and blood cells are retained.
Glomerular capillaries contain the endothelial cells podocytes and the matrix cells which
carry out the blood filtration process based on electric charge and molecular size of materials
in the blood. The first process in blood filtration is separating the blood plasma, which
contains dissolved substances, from blood cells (Patton and Thibodeau, 2018). The blood to
be filtered enters the glomerulus, a cup-like sac made up of a rich network of capillaries, and
is found at the end of each nephron. In the capillaries, there is reduced hydrostatic pressure as
they are sandwiched between arterioles and veins (Tojo and Kinugasa, 2012). The glomerulus
is supplied with blood by the afferent arteriole and the efferent arterioles collects the blood.
The constriction of the efferent arterioles prevents pressure drop by providing
resistance to blood flow. The two arterioles serving the glomerulus change in size so as to
increase or decrease the blood pressure in the glomerulus. Additionally, the diameter of the
efferent arteriole is smaller than that of the afferent tubule, this increasing further the pressure
at the glomerulus. All these characteristics, together with the fact that the heart supplies the
kidneys with a lot of blood at a time, maintains a high pressure at the glomerular capillaries
and the filtration process happens (Scott and Quaggin, 2015). Other than the use of the
nephron, the body has different ways to maintain homeostasis. These include the positive
feedback loop and the negative feedback loop. Homeostatic processes such as
osmoregulation, thermoregulation and chemical regulation in the body apply the feedback
loop.

BLOOD FILTRATION
References
Patton, K. T. and Thibodeau, G. A. (2018). The human body in health and diseases. St.
Louise, Missouri: Elsevier.
Scott, R. P. and Quaggin, S. E. (2015). The cell biology of renal filtration. The Journal of
Cell Biology, Vol. 209, No. 2, pp. 199. DOI: 10.1083/jcb.201410017
Tojo, A. and Kinugasa, S. (2012). Mechanism of glomerular albumin filtration and tubular
reabsorption. International Journal of Nephrology, Vol. 2012, Article ID. 481520, pp.
9. Doi: http://dx.doi.org/10.1155/2012/481520