Chapter 11 - Section 11.7 - Study Guide - Assess Your Learning Outcomes - Page 433: 9

Smooth muscle tissue can grow and adapt in response to various physiological and pathological factors. Two primary modes of growth for smooth muscle tissue are: 1. **Hypertrophy**: - Hypertrophy refers to the increase in the size or diameter of individual smooth muscle cells or fibers. - This mode of growth occurs when smooth muscle is subjected to increased workload or mechanical stress. As the workload on the muscle increases, individual muscle cells become larger and more robust. - Hypertrophy often occurs in response to conditions such as chronic hypertension, where the arterial walls experience increased pressure, causing smooth muscle cells in the arterial walls to thicken. - Hormonal influences, such as the action of growth factors, can also stimulate hypertrophy. 2. **Hyperplasia**: - Hyperplasia involves an increase in the number of smooth muscle cells within a tissue or organ. - This mode of growth occurs during development, tissue repair, and certain pathological conditions. - During development, smooth muscle tissue can undergo hyperplasia to increase in size and complexity. - In response to injury or damage, smooth muscle tissue can regenerate by increasing the number of cells through cell division (mitosis). For example, after an injury to the gastrointestinal lining, the smooth muscle layer may undergo hyperplasia to restore tissue integrity. - Hormonal or growth factor stimulation can also trigger hyperplasia in some situations. For example, estrogen can induce hyperplasia of smooth muscle in the uterine wall during pregnancy. It's worth noting that the extent and capacity for growth in smooth muscle tissue can vary depending on factors such as age, tissue location, and the underlying cause of growth. While some hyperplasia and hypertrophy are normal adaptive responses, excessive or uncontrolled growth can contribute to pathological conditions and diseases. For example, excessive smooth muscle growth in blood vessel walls can lead to conditions like atherosclerosis, and uncontrolled uterine smooth muscle growth can result in conditions like uterine fibroids.

Smooth muscle tissue can grow and adapt in response to various physiological and pathological factors. Two primary modes of growth for smooth muscle tissue are: 1. **Hypertrophy**: - Hypertrophy refers to the increase in the size or diameter of individual smooth muscle cells or fibers. - This mode of growth occurs when smooth muscle is subjected to increased workload or mechanical stress. As the workload on the muscle increases, individual muscle cells become larger and more robust. - Hypertrophy often occurs in response to conditions such as chronic hypertension, where the arterial walls experience increased pressure, causing smooth muscle cells in the arterial walls to thicken. - Hormonal influences, such as the action of growth factors, can also stimulate hypertrophy. 2. **Hyperplasia**: - Hyperplasia involves an increase in the number of smooth muscle cells within a tissue or organ. - This mode of growth occurs during development, tissue repair, and certain pathological conditions. - During development, smooth muscle tissue can undergo hyperplasia to increase in size and complexity. - In response to injury or damage, smooth muscle tissue can regenerate by increasing the number of cells through cell division (mitosis). For example, after an injury to the gastrointestinal lining, the smooth muscle layer may undergo hyperplasia to restore tissue integrity. - Hormonal or growth factor stimulation can also trigger hyperplasia in some situations. For example, estrogen can induce hyperplasia of smooth muscle in the uterine wall during pregnancy. It's worth noting that the extent and capacity for growth in smooth muscle tissue can vary depending on factors such as age, tissue location, and the underlying cause of growth. While some hyperplasia and hypertrophy are normal adaptive responses, excessive or uncontrolled growth can contribute to pathological conditions and diseases. For example, excessive smooth muscle growth in blood vessel walls can lead to conditions like atherosclerosis, and uncontrolled uterine smooth muscle growth can result in conditions like uterine fibroids.