Anatomy - Theme 1 - Muscular system Flashcards
what are the three types?
smooth, cardiac, skeleton
give two functions of skeletal muscle
locomotion and posture
what is the structure of skeletal muscle from the muscle fibre downwards?
muscle fibre contains myofibrils, which contain myofilaments which contain sarcomeres
what do myofilaments allow?
the muscle to contract
are muscle cells uninuclear or multinuclear?
multinuclear
what is the connective tissue surrounding each muscle cell/fibre called?
endomysium
what is the connective tissue surrounding each muscle fascicle called?
perimysium
what is the connective tissue surrounding each whole muscle called?
epimysium
where are the nuclei of skeletal muscle cells located?
peripherally
what are the set cells of muscle cells?
satellite cells
what unit makes up sarcomeres?
myofilaments
what is the function unit of a muscle cell fibre?
sarcomere
what happens to the Z line of the of the sarcomere on contraction?
they get closer
how many heads does the pec major have?
two - sternal and clavicular
what is the origin of pec major
clavicular head from clavicle and sternal head from superior 6 costal cartilage and the sternum
what is the insertion of pec major?
intertubercular sulcus of the humerus
what is the action of pec major
flexion, adduction, and medial rotation of the shoulder
what is the innervation of pec major?
lateral and medial pectoral nerves
what is the origin of pec minor
ribs 3, 4 and 5
what is the insertion of pec minor
coracoid process of the scapula
what is the action of pec minor
draws scapula back anteriorly and inferiorly and medially - stabilises scapula and elevates the ribs
what is the nerve supply of pec minor
medial pectoral nerve
what is the origin of the biceps brachii
long head from superglenoid tubercle of the scapula and short head from the coracoid process
what is the insertion of the biceps?
radius
what is the action of the biceps
flexion of shoulder and elbow, supination of the radio ulnar joint
what is the nerve supply of the biceps
musculocutaneous nerves
what is the origin of the deltoid
clavicle, acromium and spine of scapula
what is the insertion of the deleted
deltoid tuberosity of the humerus
what’s the action of the deltoid
abduction of the shoulder joint
what is nerve innervates the deltoid
axillary nerve
what is the origin and insertion of the serratus anterior?
originates upper 8-9 ribs, inserts on the medial border of the scapula
what is the action of the serratus anterior
protraction of the scapula - holds it flat against the thoracic cage
what is the nerve supply of the serratus anterior
long thoracic nerve
what are the six types of muscle arrangement and examples of each
flat, pennate - deltoid, fusiform, gastrocnemius, quadrate - quadrates femoris, circular - orbicularis oris, multiheaded - biceps brachii