| Some veins do not possess smooth muscle fibers and, as a result, do not have a tunica media. |
| The efflux of potassium ions hyperpolarizes the cell membrane, resulting in vascular smooth muscle relaxation. |
| Branched smooth muscle fibers can be found in the nipple of the mammary glands. |
| The areola contains softer and darker skin tissue which surrounds the nipple and which also contains smooth muscle fibers. |
| External injury to the alveolar wall may be the counterpart of arteriolar smooth muscle injury. |
| A microvillous tegument was appreciated overlying a thin layer of smooth muscle and a single row of stromal cells. |
