Answer:
Stem cells are currently being used to replace damaged cells or to treat some forms of cancer, usually taken from the adult hip (bone marrow)
Answer:
The trachea, commonly known as the windpipe, is a most important organ as it allows the passage of air into the lungs. Because the trachea has a soft tissue tubular formation, it needs a base of stronger, yet flexible stuff that will give it support, protect it, and still allow the passage of air into the lungs.
This is precisely the task of the tracheal rings, or cartilage rings in the trachea. These rings are made out of cartilaginous tissue, which is much stronger than the soft tissue of the tubule, but are still flexible enough to not close down the tube when air is flowing in. Thus, the tracheal rings have two tasks: one, provide support and protection for the much softer and more vunerable tube of soft tissue through which the air passes, and two, provide flexibility so that air can flow easily.
If these tracheal rings did not exist, if they are crushed, or removed, a person´s trachea would simply collapse and the person would die as air would not be able to flow through to the lungs.
One of the factors that affects the rate of weathering is exposure to the atmosphere. ... Another factor that affects the rate of weathering is the composition of rock. Rocks are composed of minerals, which are solid substances found within rocks that have their own distinct chemical composition.
