Download Muscular system

The Muscular system
Content:
1. Introduction
2. How skeletal muscle produce movement
a. Origin and insertion
b. Effects of fascicle arrangement
c. Coordination within muscle groups:
i.
Agonist & Antagonist
ii.
Synergist
iii. Fixator
3. Naming of skeletal muscle
4. Muscles that act on various joints and various parts of the
body
5. Disorders: Running injury
Compartment syndrome
Contractures
1. Introduction:
Refers to the voluntary skeletal muscle
This chapter discusses how skeletal muscle produces mevements
of various joints and various parts of the body
2. How skeletal muscle produce movement:
A. Produce movement by exerting force on tendons, which in
turn pull on bones or other structures such as skin. When such
a muscle contracts, it draws one articulating bone towards the
other where
a. the attachment to the stationary bone is the Origin and
b. the attachment to the movable bone is the Insertion
B. Effects of Fascicle arrangement:
i.
ii.
iii.
Skeletal muscle fibers are arranged within the muscle in
bundles called Fascicle
The muscle fibers are arranged in a parrallel fashion within
each bundle, but arranged of the fascicle with respect to the
tendons may take one of four characteristics patterns:
Parrellel------Stylohyoid muscle
Fusiform-----Digastric muscle
Circular------Orbicularis Oculi
Pennate: Unipinnate-----Extensor digitorum Longus
Bipinnate-------Rectus Femoris
Multipinnate----Deltoid muscle
Fascicular arrangement is correlated with the power of a
Muscle and the range of motion
C. Coordination within the muscle groups:
i.
Agonist & Antagonist:
A muscle that causes a desired action is referred as the
prime mover or Agonist
The Antagonist are those group of muscle which produce
an opposite action
Example: Biceps brochii is the prime mover or Agonist
(cause flexion) where as Tricepr brachii is the Antagonist
( causes extension)
ii.
Synergist: Muscle which serve to steady a movement and
help the prime mover to function more efficiently.
iii.
Fixators: Those muscles which stabilize the origin of the
Agonist so that it can act more efficiently.
3. How skeletal muscles are named:
Based on some characters:
i.
Direction: In which muscle fibers run
ii.
Size , shape , action & location
iii. Site of origin and insertion of the muscle
4. Muscles that act on various joints, acts on various parts of the
body and move bones of our body:
a. Muscles of Facial expression:
-Zygomaticus major
-Zygomaticus monor
-Buccinator
-Orbicularis oculi
b. Muscles that move the eye ball:
-Superior rectus
-Inferior rectus
-Lateral rectus
-Medial rectus
-Superior oblique
c. Muscles that move the mandible:
-Massater
-Temporalis
-Medial & lateral Pterygoid
d. Muscles that move the tongue:
-Genioglossus
-Styloglossus
-Hypoglossus
-Palatoglossus
e. Muscles that move the head:
-Sternocleidomastoid
-Semisspinalis capitus
f. Muscles that act on the abdominal wall:
-Rectus abdominis
-Transverse abdominis
-External oblique
-Internal oblique
g. Muscles used in breathing:
-Diaphragm
-External intercostal
-Internal intercostal
h. Muscles of the pelvis floor:
-Levator ani
-Pubococcygeus
-Iliococcygeus
-Coccygeus
i. Muscles that move the pectoral girdle:
 Anterior thoracic muscles:
-Subclavius
-Pectoralis major
-Serratus anterior
 Posterior thoracic muscles:
-Trapezius
-Lavator scapulae
j. Muscles that move the Humerus:
-Pectoralis major
-Latissimus dorsi
-Deltoid
-Teres major
-Teres minor
k. Muscles that move the forearm:
*Flexors:
-Bicepes brachii
-Brachioradialis
Brachialis
*Extensors:
-Triceps brachii
*Pronators:
-Pronator teres
Pronatorquadratus—
 Supinators:
-Supinator
5. Disorders:
i.
ii.
Running injuries: Mostly involve knee joint, Calcaneal
tendon, hip area, foot and ankle.
Compartmnet Syndrome:
Here external and internal pressure constrict structures
within the compartments. Muscle damage develop scar
tissue called ‘Contracture’