Video Transcript
The kidney contains thousands of
small tubules that filter blood to form urine. What is the scientific term given
to these tubules? (A) Capillaries, (B) ureters, (C)
ducts, (D) nephrons.
The kidney is a very important
organ of our excretory systems. Its main function is to filter the
blood, removing waste products and forming urine in the process. Blood that needs to be filtered
enters the kidneys from the renal arteries and then moves through the capillaries of
the kidneys.
Within the kidneys are thousands of
microscopic structures called nephrons. Each nephron carries out some key
processes which result in urine formation. First, the blood is filtered, and
substances like water, urea, and ions move from the blood and into the first part of
the nephron.
Then, a process called selective
reabsorption occurs. This is when useful products, for
instance, glucose and some ions, are reabsorbed back into the blood via the
capillaries that surround the nephron. Any leftover waste products and
excess water then move into the collecting ducts of the nephrons. The collecting ducts are so-called
as they collect the urine that has been formed by the nephron. This urine is then transported to
the bladder via the ureter, where it is stored until it is ready to be excreted.
Now, we have briefly reviewed the
functions of the nephrons, let’s look back at our question. We now know that the name of the
small tubules contained within the kidney that filter the blood is given by option
(D), nephrons.
