[2] Lecture 14: Appendicular Muscle Flashcards
Muscles that arise on axial skeleton or trunk fascia and insert on the girdle or limb
Begin development from blastemas w/in the body wall
Extrinsic appendicular muscles
Muscles that arise on a girdle or limb element and insert more distally
Develop from blastemas from w/in the limb
Intrinsic appendicular muscles
Note that the intrinsic blastemas originate in the ________ and are innervated by motor fibers from somatic column of spinal cord.
Somites
Lat Dorsi Levator scapulae Serratus ventralis Rhomboideus Trapiezius Sternomastoid
Exmaples of extrinsic muscles
Biceps
Triceps complex
Digit extensores and flexor….etc.
Muscles intrinsic appendicular
Dorsal group and ventral groups make up:
Extrinsic pectoral muscles
Most constant dorsal extrinsic appendicular muscle in tetrapods:
Latissiumus dorsi
Major derivative is teres major
Latissimus dorsi
2 groups of muscles from atlas/basiocciptal or form cervical vertebrae to scapular spine in amniotes
Levator scapulae
From cervical and thoracic vertebrae to dorsal border of scapula in crocodillians and mammals
Rhomboideus group
From ribs to dorsal border of scapula
Fixes the scapula.
Serratus ventralis (anterior)
Derived from fish cucullaris
May be divided into several components depending on its attachment to scapula:
Cleidotrapezius/acromiotrapezius/spinotrapezius/
Innervated by CN XI
Trapezius
Nectarus extrinsic limb muscles : [4]
Latissimus dorsi
Scapular deltoid
Supracoracoideus
Pectoralis
Originates from thoracic cage and sternum
Inserts on humerus
Major adductor of forelimb
Pectoral complex
Pectoralis: major, minor
Descendants: pectoantebrachialis
Xiphihumeralis
Components of pectoral muscle
Increase in size of latissimus dorsi
Increase in size of pectoralis complex
Supracoracoideus of amphibians and reptiles:
In mammals, surpraspinatus and infraspinatus
Trends in evo. Of pectoral muscles
Forearm adductors
Powerful flight muscles in birds
Note that supracorocoid is an intrinsic muscle in mammals
Pectoralis and supracoracoideus
Ventral group
Where does the supraspinatus and infraspinatus in mammals come from?
Supracoracoideus of amphibians and reptiles
Suspends the body btw the scapular blades in tetrapods
Scapular sling
3 muscles of scapular sling
Serratus ventralis
Levator scapulae
Rhomboids
From rib cage to medial border of scapula
Salamander: thoraciscapularis
Serratus ventralis
Anterior
From scapula to posterior skull
Lavator scapulae
Upper vertebrae to dorsal-medial border of scapula
Rhomboids
4 muscles of the rotator cuff:
Supraspinatus
Infrspinatus
Teres minor
Subscapularis
[SITS]
Composed of four muscles whose tendons of insertions form a “cuff” around the head of the humerus.
Involved in snubbing [major function] and rotating head of humerus.
Rotator cuff [SITS]
Muscle attachments on scapula ( posterior view)
[6]
Infraspinatus Teres major Teres minor Supraspinatus Triceps-long head Deltoid
Muscle attachments on scapula ( anterior view)
Subscapularis
Serratus anterior
Suprascapular notch
What muscle isn’t a part of rotator cuff?
Teres MAJOR
Levator scapulae and rhomboids are involved in what movement?
Elevation
Latissimus dorsi is involved in what movement?
Depression