Which thick layer of the heart maintains its constant pulse?

The myocardium is the thick, middle layer of the heart and is composed of cardiac muscle. Cardiac muscle is very unique because it possesses the characteristics of skeletal muscle AND smooth muscle. Skeletal muscle controls the voluntary movement of the body, while smooth muscle is responsible for the movement of all other body organs. The myocardium acts on its own, with no conscious effort.

the cytokine-activated janus kinase (jak)-signal transducer and activator of transcription (stat) pathway has an important role in the control of immune responses. dysregulation of jak-stat signaling is associated with various immune disorders.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).