Musculoskeletal System. When the body is stressed, muscles tense up. Muscle tension is almost a reflex reaction to stress â the body's way of guarding against injury and pain. With sudden onset stress, the muscles tense up all at once, and then release their tension when the stress passes. Chronic stress causes the muscles in the body to be in a more or less constant state of guardedness. When muscles are taut and tense for long periods of time, this may trigger other reactions of the body and even promote stress-related disorders.
Plates at our planet s surface move because of the intense heat in the Earth s core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down.As the cooled material sinks down, it is warmed and rises again.lates at our planet s surface move because of the intense heat in the Earth s core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when ...more.
Plate tectonic movement can cause the formation of volcanic islands. Mountains, such as Mt. Everest, are created when tectonic plates push against each other. Continental drift, a forerunner of plate tectonics, explained how the current continents once likely fit together.