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.
Men: Wear a button-down or a polo shirt, paired with khakis, or dress pants. If you so desire, layer with a v-neck sweater, a blazer, or a sport coat. A tie is optional. When to wear it: company party, daily work attire, business lunch meetings.