Download Muscular System

INTRODUCTION TO
THE MUSCULAR
SYSTEM
Part 1:
Functions, Properties &
Muscle Types
OBJECTIVES
Explain the main functions of the
muscular system
Explain the 5 major properties of
muscular system
Explain the 3 types of muscles
FUNCTION OF THE MUSCULAR
SYSTEM
The primary function is to provide
movement for the body
Muscle receive their ability to move
the body through the nervous
system
5 PROPERTIES OF THE MS
1. Excitable or irritable
… They are capable of receiving stimulation and
responding to stimulation from the nerves
2. Contractible
… They are capable of contracting or shortening
after receiving stimulation
3. Extensible
… A muscle can be stretched without damage by
the application of force
5 PROPERTIES OF THE MS
4. Elasticity
… A muscle is able to return to its original resting
shape and length after being extended or
contracted
5. Adaptability
… It can be changed in response to how it is used
… A muscle can enlarge (hypertrophy) through
increased work
… A muscle can waste away (atrophy) if deprived
of work
MUSCLE DEFINED
 Is an organ that can contract in a coordinated
fashion and includes muscle tissue, blood
vessels, nerves and connective tissue
 Two different controls of muscles:
… Voluntary: is movement that is controlled
consciously such as moving arms and legs.
… Involuntary: is movement that is controlled
without conscious thought such as contraction
of the stomach wall
MUSCLE TYPES
Three types of muscle tissue:
…Skeletal
…Smooth
…Cardiac
SKELETAL MUSCLE
 Is responsible for moving parts of the body
… For example: your limbs, trunk, & face
 It is made up of elongated cells called muscle fibers
 Each fibers contains many nuclei and is crossed by
light and dark stripes called striations
 Skeletal muscle fibers are grouped into dense
bundles called fascicles
 These fascicles are bound together by connective
tissue to form a muscle
 Skeletal muscle is voluntarily controlled
SKELETAL MUSCLE
SMOOTH MUSCLE
 Forms the walls of the stomach, intestines,
blood vessels and other internal organs
 Individual cells are spindle shaped, have a
single nucleus, and interlace to form sheets
 It lacks striations and is surrounded by
connective tissue
 It is involuntarily controlled
SMOOTH MUSCLE
CARDIAC MUSCLE
 Makes up the walls of the heart
 It is striated and is involuntarily controlled
 The junction of one cell with another in a particular
chain is known as an intercalated disc
… It appears as a heavy dark line running across the
fiber
 Each cell has a somewhat cylindrical shape with one
centrally-located, oval nucleus.
 Cross-striations are apparent but they are not as
regular nor as prominent as those of skeletal muscle
CARDIAC MUSCLE
Oval-shaped nucleus
Intercalated Disc