Physiology of Smooth Muscles -Mechanics of contraction and relaxation

In this comprehensive lecture by Dr. Faiza, Assistant Professor of Physiology at CIMS Multan, learners are guided through the intricate physiology of smooth muscles. Dr. Faiza begins by elucidating the characteristics and significance of contraction in unitary and multiunit smooth muscles, emphasizing their distinct structural and functional features. The lecture delves into the mechanisms underlying smooth muscle contraction, highlighting the absence of troponin complex and striations, as well as the role of actin, myosin, and calcium dynamics. Dr. Faiza also explores the diverse stimuli that trigger smooth muscle contraction, including nerve stimulation, hormonal influences, and changes in the chemical environment. With a detailed examination of the neuromuscular junction and membrane potential dynamics, learners gain insights into the electrogenic properties and pacemaker activity of smooth muscles. Additionally, the lecture explores mechanisms of smooth muscle relaxation, including the slow calcium pump and myosin phosphatase activity. Special emphasis is placed on the unique characteristics of smooth muscle mechanics, such as stress relaxation and the latch phenomenon, which contribute to their slow, economical, and sustained contraction capabilities.Read less