MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

BIOLOGY

SECTION 1. BIOLOGICAL BASES OF HUMAN VITAL ACTIVITY

1.2. CELL. TISSUES. CONCEPT OF AN ORGAN, ORGAN SYSTEM, ORGANISM

MUSCULAR TISSUE

1. Cytology/cytology/32.html">SMOOTH Muscle tissue

Smooth muscle tissue (Fig. 1.22) is located in the walls of Blood Vessels and most hollow Internal Organs, such as the Esophagus, Stomach, intestines, Urinary Bladder, Uterus, etc. The morphological feature of smooth muscle tissue is its cellular Structure and the presence of a contractile apparatus in the form of smooth myofibrils.

Class="center">

Fig. 1.22. Smooth muscle Cells: 1 - smooth myocyte; 2 - Cell Nucleus; 3 - Cytoplasm; 4 - cell processes.

Functionally, smooth muscle tissue is characterized by relatively slow contractions and The ability to maintain a contracted state for extended periods. In doing so, it expends a relatively small amount of energy and, accordingly, does not fatigue as quickly as striated musculature. This type of contractile activity is referred to as tonic. Smooth muscle tissue is innervated by the Autonomic Nervous system and therefore, unlike striated musculature, it is not subject to our conscious will, although it remains under the control of the Cerebral Cortex, much like all Other types of contractile Tissues.

The basic structural unit of smooth muscle tissue is the smooth muscle cell, or smooth myocyte. It has an elongated, spindle-like shape with tapered ends. Smooth muscle tissue is characterized by a very dense arrangement of its cells.