Haversian canals (also called central canals) run longitudinally through the bone and contain blood vessels and nerves which supply the bone.
Business casual: Generally means khaki pants, a plain polo shirt or a long-sleeved casual button-down oxford shirt, a V-neck sweater, sometimes a sports coat or blazer, and brown leather shoes. Loafers are a good choice, and you should wear socks.
In cool weather, you can add a blazer or sweater. Women's business casual choices range from dress pants or a knee-length or longer skirt and a blouse to a dress that comes at least to the knee. Appropriate shoes include sling-backs, flats and boots, but you should avoid flip-flops and tennis shoes.