Skeletal Muscular System - Appendicular Flashcards
Extrinsic Muscles
Originates outside the limb and Insertions are within the limb
often large dynamic movers
Intrinsic Muscles
muscles that originate and insert within the upper limb itself
Subgroups:
Anterior/Posterior Arm Muscles,
Anterior/Posterior Forearm Muscles,
Muscles of Hand
4 Anterior Axioappendicular
1 Pectoralis Major Muscle
2 Serratus Anterior Muscle
3 Subclavius Muscle
4 Pectoralis Minor Muscle
attached more anteriorly on thoracic wall. Origin on Axial and Inserts on Appendicular (thus the name)
Pectoralis Major
largest/most superficial of anterior axioappendicular muscles
large, dynamic move of upper limb
powerful adduction + medial rotation of the arm
Pectoralis Minor
deep to pectoralis major
Origin: 2-4, sometimes 5 rib
Insert: Coracoid process of Scapula
stabilizes scapula
Subclavius Muscle
directly below scapula
depesses should, stabilizes clavivle during mvmt of upper limb
Serratus Anterior
Origin: anterior ribs
Insert: scapula
most powerful muscle of pectoral girdle; protractor of scapula, keeps scapula anchored against posterior thoracic wall
4 Posterior Axioappendicular Muscles
1 Trapezius
2 Latissimus Dorsi
3 Levator Scapulae
4 Rhomboid Major, Minor
counterparts to anterior group
Trapezius
large, superficial, diamond shaped muscle
Origin: skull, upper vertebrae
Insert: clavicle, scapulae
elevates scapula, rotation of later parts of scapula upwards, facilitates in raising upper limb above the head
Latissimus Dorsi
flat muscle located inferior + deep to trapezius
large dynamic mvmt, extension, adduction, medial rotation of upper limb; depression of shoulder
Levator Scapulae
deep to trapezius, superior to spine of scapula.
Rhomboid Major/Minor
retracts the scapula
4 Rotator Cuff Muscles
S.I.T.S.
Supraspinatus (superior to spine of scapula)
Infraspinatus (inferior to spine of scapula)
Teres Minor (inferior, posterior, lateral part of scapula)
Subscapularis (anterior of scapula) (medial rotation of upper limb)
ASSIST IN KEEPING THE HEAD OF THE HUMERUS IN THE GLENOID FOSSA
supraspinatus assist the deltoid in abduction of arm for first 15 degree
other muscles all rotate the humerus
3 Muscles of Anterior Arm
1 Biceps Brachii
2 Coracobrachialis
3 Brachialis
Biceps Brachii
most superficial/anterior that attached to radius
long head is more lateral, longer tendon
short head is medial
cross shoulder + elbow joints for shoulder+ elbow flexion; supination of elbow joint
Coracobrachialis
deep to short head of biceps brachii + shares attachment w short head
Brachialis
real dominant elbow flexor
mid humerus + attached to ulna
5 Muscles of Posterior Arm
Teres Minor Teres Major Medial Head of Triceps (deepest of triceps) Long Head of Triceps Lateral Head of Triceps
Triceps
major forearm extensor mainly carried out by medial and lateral head
Long Head of Triceps
crosses both elbow and shoulder joints
most superficial and posterior
Flexors of the Forearm
muscles that originate from the MEDIAL epicondyle
Extensors of the Forearm
muscles that originate from the LATERAL epicondyle
Anterior Forearm Muscles:
Superficial Layer
from lateral to medial: Pronator Teres Flexor Carpi Radialis Palmaris Longus Flexor Carpi Ulnaris
all originate in medial epicondyle
Pronator Teres
Origin: medial epicondyle of humerus, + ulna
Insert: Radius
weak flexion of elbow joint; pronation of forearm
Flexor Carpi Radialis
Origin: medial condyle of humerus
Insert: 2nd base of metacarpal
flexion of wrist + abduction of hand