Notes: please adhere to the guidelines explained in. Histology 101, which can be found under the laboratory tab on our owl site. Marks may be deducted if you do not read and follow these instructions. Lab assignment 8: heart & circulatory system histology guide, chapter 9: using slide mh 065-066 aorta and vena cava draw the aorta and the vena cava. Label six features, in total, that are specific to the tissue that you learned about in today"s lab. (4 marks) Subendocardial layer of endocardium: what is an identifying feature of purkinje fibers? (0. 5 mark) Significantly larger in size with large amounts of glycogen and fewer myofibrils than other cardiac muscle cells: compare and contrast arteries and veins. Complete the following chart, providing one identifying feature for each vessel that helped you determine that it would be identified as such. (2 marks) Thin tunica media with irregular lumen of relatively large diameter. Very thin-walled endothelium, only thickened at the nucleus.