Metastability in the brain for a continuum of integration. One theory used to integrate the dynamic core with conscious thought involves a developing concept known as neural Darwinism. In this model, metastable interactions in the thalamocortical region cause a process of selectionism through re-entry (a phenomenon describing the overall reciprocity and interactivity between signals in distant parts of the brain through coupled signal latency). Neuronal selectivity involves mechanochemical events that take place pre- and post-natally whereby neuronal connections are influenced by environmental experiences. The modification of synaptic signals as it relates to the dynamic core provides further explanation for the DCH. Despite growing evidence
Systole Systole of the heart is initiated by electrically excitable cells situated in the sinoatrial node. These cells are activated spontaneously by depolarization of the electrical potential across their cell membranes, which causes voltage-gated calcium channels on the cell membrane to open and allow calcium ions to pass through into the sarcoplasm (cytoplasm) of cardiac muscle cells. Calcium ions bind to molecular receptors on the sarcoplasmic reticulum (see graphic), which causes a flux (flow) of calcium ions into the sarcoplasm. Calcium ions bind to troponin C, causing a conformational (i.e., structural) change in the troponin-tropomyosin protein complex, causing the myosin head