L6 Principles of the Muscular System Flashcards
What is locomotion?
requires contraction of muscle fibres (cells) Contractile proteins (myofilaments) arranged as myofibrils
What are the key features of skeletal muscle?
What are the different levels of CT?
Elongated and multinucleated
Peripheral nuclei
Bundles = fascicles
CT: Epimysium, Perimysium and endomysium
What causes movement of muscles, in terms of shortening?
Shortening between origin and insertion
What are the connective tissues of muscles?
Epimysium surrounds entire muscle, Perimysium surrounds fascicles
Regenerate - satellite cells
What is a sarcomere?
smallest functional unit of a skeletal muscle fibre
What are the myofilaments?
Actin (Thin)
Myosin (Thick)
Pectoralis Major origin/insertion
Origin: Clavicle, sternum and costal cartilages
Insertion: Humerus
Pectoralis Major action
Flexion, adduction and internal rotation of the shoulder joint
Pectoralis Major innervation
Lateral and Medial Pectoral nerve
Pectoralis Minor origion/inserion
Origin: Ribs 3, 4 and 5
Insertion: Corocoid process of the scapula
Pectoralis Minor action
Draws scapula anteriorly, inferiorly and medially
Elevates the ribs
Pectoralis Minor innervation
Medial Pectoral nerve
Biceps brachii origin/insertion
Origin:
Long head: Supraglenoid tubercle of the scapula
Short head: Corocoid process of the scapula
Insertion: Radius
Biceps brachii action
Flexion of the shoulder joint
Flexion of the elbow joint
Supination of the radio-ulnar joints
Biceps brachii innervation
Musculocutaneous nerve