muscles of shoulder+ arm & abdomen and back Flashcards
supraspinatus
Origin: supraspinous fossa
Insertion: greater tubercle of humerus
Action: abduction of arm of shoulder
Innervation: suprascapular nerve
infraspinatus
Origin: infraspinous fossa
Insertion: greater tubercle of humerus
Action: external (lateral) rotation of arm at shoulder
Innervation: suprascapular nerve
teres minor
Origin: lateral border of scapula
Insertion: greater tubercle of humerus
Action: external (lateral) rotation of arm at shoulder
Innervation: axillary nerve
subscapularis
Origin: subscapular fossa
Insertion: lesser tubercle of humerus
Action:
1. medial (internal) rotation of arm at shoulder
2. adduct arm at shoulder
Innervation: subscapular nerves
deltoid
Origin: lateral clavicle, acromion, spina of scapula
Insertion: deltoid tuberosity of humerus
Action:
1. abduction of arm at shoulder
2. medial and lateral rotation
3. flexion and extension
Innervation: axillary nerve
coracobrachialis
Origin: coracoid process of scapula
Insertion: medial shaft of humerus
Action:
1. adduction of arm at shoulder
2. flexion of arm at shoulder
Innervation: musculocutaneous nerve
what is not true about the deltoid
a) it abducts the arm
b) it adducts the arm
c) it flexes and medially rotates
d) it extends and laterally rotates
B)
muscles of the rotator cuff
- supraspinatus
- infraspinatus
- teres minor
- subscapularis
muscles- non rotator cuff
- deltoid
- coracobrachialis
- pectoralis major
- latissimus dorsi
- teres major
biceps brachii
Origin:
- long head: supraglenoid tubercle of scapula
- short head: coracoid process
Insertion: radial tuberosity
Action:
1. flexes arms and forearm at elbow
2. abducts and medially rotates arm
3. supination
Innervation: musculocutaneous nerve
brachialis
Origin: anterior humerus
Insertion: ulnar tuberosity and coronoid process
Action:
1. flexes forearm at elbow
Innervation: musculocutaneous and radial nerve
brachioradialis
Origin: lateral supracondylar ridge (proximal 2/3)
Insertion: styloid process of radius
Action: flexes forearm at elbow joint
Innervation: radial nerve
triceps brachii
Origin:
- long head: scapula
- lateral head: humerus
- medial head: humerus
Insertion: olecranon of ulna
Action:
1. extends and adducts arm
2. extends forearm
Innervation: radial nerve
muscles that move the arm/forearm
- biceps brachii
- brachialis
- brachioradialis
- triceps brachii
- pronators
- supinator
external oblique location
- outermost abdominal muscle
- situated on the lateral and anterior aspect of the abdominal wall
external oblique
Origin: ribs 5-12
Insertion: linea alba, iliac crest, pubic crest
Action:
- bilateral: contraction; flexion of the vertebral column; abdominal compression
- unilateral: contraction: lateral flexion; trunk rotation
abdominal compression
contributes to forceful expiration, defecation, support for abdominal viscera & stabilizing pelvis
internal oblique
Origin: thoracolumbar fascia*, iliac crest
Insertion: linea alba, pubis, inferior ribs & costal cartilage
Action: same as external oblique except: rotation to ipsilateral (same side)
thoracolumbar fascia
- multilayer arrangement of fascia
- sheet of connective tissue in the lumbar region
aka: lumbodorsal fascia
rectus abdominis
Origin: pubic symphysis
Insertion: xiphoid process, costal cartilage of ribs 5-7
Action: flexion of the trunk, abdominal compression
about the rectus abdominis (abs)
- strap-like muscle that extends the length of the anterior abdominal wall
-separated on either side by the linea alba
tendinous intersections
- transverse, fibrous bands that partially separate the muscle fibers of the rectus abdominis into segments
transversus abdominis
Origin: costal cartilage of interior ribs, iliac crest, thoracolumbar fascia
Insertion: linea alba, pubis
Action: abdominal compression
rectus sheath
formed by the aponeuroses of:
- external oblique, internal oblique, and transversus abdominis
aponeurosis- sheet like tendon by which muscles connect to bone or fascia
- encloses the rectus abdominis
muscles of the back
- trapezius
- latissimus dorsi
- levator scapulae
- teres major
- rhomboids (major + minor)
- erector spinae muscles
trapezius
Origin: occipital bone of the skull, spinous processes of thoracic vertebrae
Insertion: scapula (acromion and scapular spine); lateral aspect of clavicle
sections of trapezius + actions
upper fibers- elevate scapula
middle fibers- retract scapula & upward rotation of scapula
lower fibers- depress scapula & upward rotation of scapula (arm abduction)
latissimus dorsi
Origin: spinous processes of lower thoracic vertebra & lumber vertebrae (T6-L5), sacrum, iliac crest, thoracolumbar fascia
Insertion: humerus (intertubercular groove)
Action:
- adduction of arm
- extension of arm
- medial rotation of arm at shoulder
innervation: thoracodorsal nerve (brachial plexus)
levator scapulae
Origin: transverse processes superior cervical vertebrae (C1-C4)
Insertion: superior/ medial border of scapula
Action: elevation of the scapula
Innervation: dorsal scapular nerve (brachial plexus)
rhomboids major and minor
Origin: spinous processes of C7-T5
Insertion: medial border of the scapula
Action: retraction of the scapula
Innervation: dorsal scapular nerve (brachial plexus)
teres major
Origin: inferior angle of scapula, posterior aspect
Insertion: medial lip of intertubercular groove
Action:
- adduction of arm
- extension of arm
- internal rotation of arm
Innervation: lower subscapular nerve (brachial plexus)
erector spinae muscles
deep group of 3 paired longitudinal muscles running along the vertebral column
1. iliocostalis- lateral
2. longissimus- middle
3. spinalis- medial
erector spinae muscles actions
bilateral: contraction: extension of the vertebral column
unilateral contraction: lateral flexion of the vertebral column
the muscles that originated from the pubic symphysis is:
a) internal oblique
b) rectus abdominis
c) transversus abdominis
d) spinalis
b) rectus abdominis
