The elastic layer visible in Fig. 4.1, lying between the endothelium and the tunica media, is one clue that the blood vessel is the renal artery rather than the renal vein, which could be a similar size. Complete the sentence with one further visible structural feature that would show the blood vessel is an artery. This is an artery because it has ..........
Describe the link between the structure of the tunica media and the function of an artery, such as the renal artery.
At point $X$-$Y$ in Fig. 4.1, the actual diameter of the lumen of the renal artery is $5.2\,\text{mm}$. Calculate the magnification of the image in Fig. 4.1. State the formula you will use in your calculation and show all working.
Blood plasma is approximately $90\%$ water. Many of water’s properties result from hydrogen bonding. Outline how water’s properties make it suitable as the major constituent of plasma.