Muscles – Trunk, Head, Neck
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The Muscular System
Trunk, Head, and Neck
Muscle cells are specialized for contraction.
Muscle cells tend to be quite
There are three distinct types of muscle tissue:
skeletal, smooth, and
cells are long, cylindrical, and multi-nucleated (i.e., have more
than one nucleus).
Skeletal muscle is also distinctive because the cells are striated,
meaning that they appear striped from side-to-side.
is so called
because it lacks striations; smooth muscle is also called visceral muscle, because it is
found in the hollow organs of the viscera.
Smooth muscle cells tend to be shorter and
spindle-shaped (aka, fusiform).
You may have noticed some of these cells underlying
the pseudostratified columnar epithelial tissue looked at in the tissue lab.
cells are similar to skeletal muscle in that they are striated.
Each cell, however,
contains only a single, centrally-placed nucleus.
Adjacent cells are joined together by
special junctions called ‘intercalated
, and individual fibers tend to be branched,
such that the interconnected fibers form a complex network.
Observe the slides of muscle tissue. In the spaces below, draw diagrams of
skeletal, smooth, and cardiac muscle tissue.
The primary function of skeletal muscles is to move the bones of the skeleton.
bones serve as levers
, which move around a pivot point, called the fulcrum
body, the various synovial joints act as fulcrums.
There are three different types of