Question

Unlike skeletal muscle, smooth muscle may spontaneously contract when it is stretched. What feature of smooth muscle allows it to stretch without immediately resulting in a strong contraction?

Answer 1

stress-relaxation response

Step-by-step explanation:

Stretching of smooth muscle provokes contraction. However. The increased tension persists only briefly. Soon the muscle adapts to its new length and

relaxes. While still retaining the ability to contract on demand. The stress-relaxation response of smooth muscle allows a hollow organ to fill or expand

slowly to accommodate a greater volume without promoting strong contractions that would expel its contents.

Answer 2

The smooth muscle can stretch without immediately resulting into strong contraction because of the SLOWNESS OF THE ATTACHMENT AND DETACHMENT OF THE CROSS-BRIDGES WITH THE ACTIN FILAMENTS, also the INITIATION OF CONTRACTION DUE TO CALCIUM ION IS SLOWER.

Step-by-step explanation:

The number of time that the cross bridges remain attached to the actin filaments in smooth muscles is increased leading to slower force of contraction. It can be deduced to be so because the cross bridge heads have far less ATPase activity than in skeletal muscles resulting in the reduction in the degradation of ATP that energies the movements of the cross bridge heads and therefore slow rate of cycling.

There is also the LATCH mechanism which explains why once smooth muscle has reached full contraction, the muscle can still maintain its full contraction as the amount of continuing excitation is reduced to far less than the initial level. This helps in maintaining prolonged tonic contraction in smooth muscles with little use of energy. Hope you got that.