Smooth muscle contraction is a vital component of the functioning of blood vessels, the uterus, airways and the bladder. Its malfunction can lead to serious pathological conditions, such as hypertension and pre-term labour. The calcium ion plays a central role in smooth muscle function, increasing in concentration for contraction and decreasing for relaxation. Calcium entry into the cell is facilitated by the sarcoplasmic reticulum (SR).This book explores the latest research on the role of the sarcoplasmic reticulum (SR) in smooth muscle function. It examines the control and modulation of the SR and how this may vary among smooth muscle types. Potential therapeutic implications are also discussed.Discusses new and exciting work in this area and identifies promising new research directions.Considers the advances in this relatively unexplored field, offering new insights into the role of the SR muscle.Brings together contributions from key workers, both in basic and clinical science, whose studies range from physiological to pathological and molecular to whole animal.