The bow is about 7' long, and is sized to the archer. So a shorter person would have a shorter bow.
My arrow is between 36 and 37 inches in length. Traditionally the bow (Yumi) is made from bamboo with a hardwood inner core, however they can be made from more modern materials. Here in Nevada a bamboo bow would be very hard to take care of because of the dry climate so we use composites of wood and fiberglass.
The arrows (Ya) are also traditionally made from bamboo, however aluminum or carbon fiber are quite popular.
The Fletching is usually from a turkey though in Japan they use sea eagle feathers.
Earlier I mentioned a wrist guard isn't needed. That's because of the dynamics of the shot. The arrow rests on the outside of the bow for starters, also the bow is gripped in a way that permits the bow to spin around in the hand. When one gets good at it, the string will bounce off the back of the wrist, having traveled almost 360 degrees.