Crystal. When most people talk about bringing out the crystal, they are often referring to a type of glass that is made from silica, lead oxide, soda or potash, and other additives. Lead crystal is prized for its durability and decorative properties, even if it does not necessarily possess a crystalline structure.
What part of the brain controls breathing and heartbeat? The brain stem controls breathing and heart rate as well as blood pressure and alertness. Found at the top of the spinal column, the brain stem consists of three main parts, including the medulla oblongata, pons and midbrain. The medulla oblongata controls cardiac and respiratory rates.
It sends a message to the respiratory muscles telling them when to breathe. The medulla, located nearest the spinal cord, directs the spinal cord to maintain breathing, and the pons, a part of the brain very near the medulla, provides further smoothing of the respiration pattern. This control is automatic, involuntary and continuous.