Download Muscular System

Muscular System
Muscular System
• Muscles are contractile organs responsible for
the voluntary and involuntary movements of
animals.
Types of Muscle
• Skeletal Muscle
– Allow for all voluntary movement
– Appears to be striated under a microscope
• Cardiac Muscle
– Controls the involuntary beating of the heart
– Appears striated under a microscope
• Smooth Muscle
– Responsible for all other involuntary movement, such as
breathing, digesting, peristalsis, blinking, etc.
Movement
• Ambulation
– Moving from one place to another
• Abduction
– Moving away from the median plane
• Adduction
– Moving towards the median plane
• Flexion
– Moving the distal part of the limb towards the body
• Extension
– Moving the distal part of the limb away from the body
Muscle Function
• All muscles can do is CONTRACT of RELAX
– Generally work in pairs
• Agonist-Prime mover of a joint
• Antagonist-Opposes movement of the agonist
• Example
– Elbow flexion
• AgonistBicep
• AntagonistTricep
Major Muscles
• Masseter-Superficial muscle of the cheek
• Trapezius-Superficial triangular muscle of the shoulder
• Latissimus dorsi-Long, superficial, dorsal muscle that
attaches the humerus to the lumbar region of the back.
• Abdominal obliques-Large flat muscles that support
digestive and reproductive organs
Major Muscles
• Gluteals-Large muscle of the upper hindquarters.
• Biceps femoris-lateral superficial muscle, one of the
three which forms the “hamstrings”
• Biceps brachii-primary flexor of the elbow joint
• Triceps brachii-primary extensor of the elbow joint
• Pectorals-Primary adductors of the forelimbs
• Serratus ventralis-attaches forelimb to the trunk
Brachiocephalicus
Masseter
Trapezius
Latissimus
dorsi
External abdominal
oblique
Gluteals
Pectorals
Semitendinous
Deltoid
Triceps
brachii
Gastrocnemius
Intercostal
Biceps
femoris