Exercise 2

Question 1

how is the nephron defined? What is another name for the nephron?

Answer 1

The nephron is defined as a microscopic kidney unit that regulates blood composition by glomerular filtration, tubular reabsorption, and tubular secretion. The end result will be the production of urine. There are over one million nephrons in a kidney. Another name for nephrons is renal or kidney tubules.

Question 2

​List the blood vessels associated with the nephron in the order of blood flow into the nephron, through it and away from it.

Answer 2

Each nephron has its own blood supply. Blood enters the nephron from the renal artery. The renal artery narrows, eventually becoming the smaller afferent arteriole, which brings the blood into the glomerulus, the first of the capillary networks. From here the blood will leave the glomerular capsule by way of the efferent arteriole and substances that remain in the capsule will then enter the first of the tubules. Blood in the efferent arteriole is then transported into the second network of capillaries called the peritubular capillary network. Any substances entering the blood from this network are then delivered to venules that lead into the renal vein which carries the blood back to the heart via the venous system

Question 3

​What is the glomerulus?

Answer 3

The glomerulus is the first of two capillary networks. It is found inside the glomerular capsule.

Question 4

what are the five main parts of the nephron anatomy and in which region of the nephron is each located?

Answer 4

The five main parts of the nephron anatomy in order of appearance are:

i) ​glomerular capsule – located in the renal cortex
ii) ​proximal convoluted tubule – located in the renal cortex
iii) ​loop of the nephron – located in the renal medulla
iv) ​distal convoluted tubule – located in the renal cortex
v) ​collecting ducts – located in the renal medulla

Question 5

What is the function of each part of the nephron?

Answer 5

Glomerular capsule – formation of the glomerular filtrate a filtrate of the blood
​Proximal convoluted tubule – tubular reabsorption – rebsorption of water, salts and nutrients from the tubule back into the blood
​Loop of the nephron – descending portion – reabsorption of water
- - ascending portion – reabsorption of salt
​Distal convoluted tubule – tubular secretion – movement of substances from the blood into the tubule forming a filtrate called urine
​Collecting ducts – collects urine from many distal convoluted tubules and carries urine to renal pelvis which is continuous with

Question 6

What are the three main regions of the kidney and briefly describe each?

Answer 6

​The three main regions of the kidney are:
i)​renal cortex – the outer portion of the kidney that appears granular. It dips down between the striated layers of the renal medulla. It contains the majority of the nephron including the glomerular capsule and both the proximal and distal convoluted tubules.
ii)​renal medulla – the inner layer of the kidney that consists of cone-shaped tissue masses called renal pyramids. It contains the loop of the nephron, most of the peritubular capillary network and the collecting duct.
iii)​renal pelvis – central cavity that is continuous with the ureter. It receives the urine from the collecting ducts on its way into the ureters.
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