Heart rate persons with coronary artery disease. The heart rate is rhythmically generated by the sinoatrial node. It is also influenced by central factors through sympathetic and parasympathetic nerves. Nervous influence over the heartrate is centralized within the two paired cardiovascular centres of the medulla oblongata. The cardioaccelerator regions stimulate activity via sympathetic stimulation of the cardioaccelerator nerves, and the cardioinhibitory centers decrease heart activity via parasympathetic stimulation as one component of the vagus nerve. During rest, both centers provide slight stimulation to the heart, contributing to autonomic tone. This is a similar concept to tone in skeletal muscles. Normally, vagal stimulation
The Time Warp of Dr. Brain The Time Warp of Dr. Brain The Time Warp of Dr. Brain is the fourth installment of the educational game series "Dr. Brain" by Sierra On-Line. The game's structure is similar to its predecessor, "The Lost Mind of Dr. Brain": the player must complete several puzzles which appeal to a specific part of the brain; however, this game also adds a time-period based theme to each puzzle and the game's theme overall is time travel. Like the previous titles, "The Time Warp of Dr. Brain" is a simple point-and-click. The objective of the game is to successfully complete a set