THE MUSCULAR SYSTEM
Human anatomy and physiology
Muscle Types Based on Pattern of Fascicle Organization.
A lever is a rigid structure such as a board, a crowbar, or a
bone- that moves on a fixed point called the fulcrum.
The load can vary from the weight of an object held in the hand
to theweight of a limb or the weight of the entire
body,depending onthe situation.
A lever moves when pressure called an applied force is
sufficient to overcome any load that would otherwise oppose
or prevent such movement.
FIRST CLASS
LEVER
SECOND CLASS
LEVER
THIRD - CLASS LEVER
Origin and insertion
The place where the fixed
end attaches to a bone,
cartilage, or connective
tissue is called the origin of
the muscle.
The site where the
movable end attaches to
another structure is
called the insertion of the
muscle.
Actions
When a muscle moves a portion of the skeleton, that movement
may involve flexion, extension, adduction, abduction, protraction,
retraction, elevation, depression, rotation, circumduction, pronation,
supination, inversion, eversion, lateral flexion, opposition, or
reposition.
 An agonist, or prime mover, is a muscle whose contraction is
mostly responsible for producing a particular movement.
 An antagonist is a muscle whose action opposes that of a
particular agonist
 When a synergist contracts, it helps a larger agonist work
efficiently. Synergists may provide additional pull near the
insertion or may stabilize the point of origin.
 Synergists may also assist an agonist by preventing movement at
another joint, thereby stabilizing the origin of the agonist. Such
synergists are called fixators.
Fascicle Organization
Rectus - “straight,” and rectus muscles are parallel muscles whose
fibers run along the long axis of the body.
Position
Externus (superficialis) - muscles visible at the body surface.
Internus (profundus) - deeper muscles
Extrinsic - Superficial muscles that position or stabilize an organ
Intrinsic - muscles located entirely within an organ.
Axial and Appendicular Muscles
Muscles of the Head and Neck
Muscles of Facial Expression
 Orbicularis oris muscle
constricts the opening, and
other muscles move the lips or
the corners of the mouth.
 Buccinator muscle has two
functions related to eating (in
addition to its importance to
musicians).
Extrinsic Eye Muscles also known
as the oculomotor muscles,
originate on the surface of the
orbit and control the position of
each eye.
Muscles of Mastication
 large masseter muscle is the
strongest jaw muscle.
 temporalis muscle assists in
elevation of the
mandible.excursion.
 pterygoid muscles, used in
various combinations, can
elevate, depress, or protract the
mandible orslide it from side to
side, a movement called lateral
excursion.
Muscles of Facial Expression
Extrinsic eye muscle
Muscles of mastication
Muscles of the Tongue
 The palatoglossus muscle
originates at the palate, the
styloglossus muscle at the
styloid process of the
temporal bone, the
genioglossus muscle at the
chin, and the hyoglossus
muscle at the hyoid bone.
Muscles of the Pharynx
 The pharyngeal constrictor
muscles (superior, middle, and
inferior) move food into the
esophagus by constricting the
pharyngeal walls.
 The laryngeal elevator muscles
elevate the larynx. The two palatal
muscles-the tensor veli palatini and
the levator veli palatini - elevate
the soft palate and adjacent
portions of the pharyngeal wall
and also pull open the entrance to
the auditory tube.
Muscles of the Anterior Neck
 The digastric muscle
has two bellies, as the
name implies (di-,
 two gaster, stomach).
One belly extends
from the chin to the
hyoid bone; the other
continues from the
hyoid bone to the
mastoid portion of the
temporal bone.
Muscles of the Vertebral Column
 The erector spinae
muscles include
superficial and
deep layers. The
superficial layer can
be divided into
spinalis,
longissimus, and
iliocostalis groups.
Oblique and Rectus
Muscles
Muscles of the Pelvic Floor
REPORTED BY: EKANG BAUTISTA