The muscular system contains three main types of muscle tissue: cardiac, smooth, and skeletal. Cardiac muscle is found only in the heart, has striations and connects to other cardiac cells. Smooth muscle lines hollow organs and contracts slowly and continuously. Skeletal muscle is voluntary, attached to bones by tendons, and produces movement and posture. Muscles have characteristics of excitability, contractility, extensibility, and elasticity that allow movement and maintenance of body temperature and posture.

1. Muscular
System

2. There are four characteristics associated with
muscle tissue:
 Excitability - Tissue can receive & respond to
stimulation
 Contractility - Tissue can shorten & thicken
 Extensibility - Tissue can lengthen
 Elasticity - After contracting or lengthening,
tissue always wants to return to its resting
state
Functions

3. The characteristics of muscle tissue enable it to
perform some important functions, including:
 Movement – both voluntary & involuntary
 Maintaining posture
 Supporting soft tissues within body cavities
 Maintaining body temperature
Functions

4. The Muscular System
 Muscles are responsible for all types of
body movement – they contract or
shorten and are the machine of the
body
 Three basic muscle types are found in
the body, what are they?

5. 3 Types of Muscle
 The human body is comprised of 324 muscles
 Muscle makes up 30-35% (in women) and 42-47% (in men)
of body mass
Cardiac
Smooth
Skeletal

6. Cardiac Muscle Characteristics
 Has striations
 Usually has a single
nucleus
 Joined to another muscle
cell at an intercalated
disc
 Involuntary
 Found only in the heart
 Steady pace!

7. Smooth Muscle Characteristics
 Has no striations
 Spindle-shaped cells
 Single nucleus
 Involuntary – no
conscious control
 Found mainly in the
walls of hollow organs
 Slow, sustained and
tireless

8. Skeletal Muscle Characteristics
 Most are attached by tendons to bones
 Cells are multinucleate
 Striated – have visible banding
 Voluntary – subject to conscious control
 Cells are surrounded and bundled by
connective tissue = great force, but tires
easily

9. Characteristics of Muscles
 Muscle cells are elongated
(muscle cell = muscle fiber)
 Contraction of muscles is due to the
movement of microfilaments
 All muscles share some terminology
Prefix myo refers to muscle
Prefix mys refers to muscle
Prefix sarco refers to flesh