Muscle - Function, Origin, Insertion

Question 1

deltoid function

Answer 1

abduct arm up to 90 degree perpindicular to body
anterior fibers: flexion, medial rotation
middle fibers: abduction
posterior fibers: extension & lateral rotation of humerus

Question 2

deltoid origin

Answer 2

anterior fibers: lateral third of clavicle
middle fibers: acromion process
posterior fibers: spine of scapula

Question 3

deltoid insertion

Answer 3

all 3 fibers converge to insert on deltoid tuberosity (Vshape on lateral humeral shaft)

Question 4

Rotator cuff muscles

Answer 4

Supraspinatus, Infraspinatus, Teres minor, Subscapularis
SITS

Question 5

supraspinatus function

Answer 5

abduction initiator of humeral abduction
Very vulnerable to tear/impingement

Question 6

supraspinatus origin

Answer 6

supraspinatus fossa of scapula

Question 7

supraspinatus insertion

Answer 7

superior facet of greater tuberosity of humerus (medial)

Question 8

infraspinatus function

Answer 8

external/lateral rotation of shoulder, assist in shoulder extension and adduction

Question 9

infraspinatus origin

Answer 9

infraspinous fossa of scapula

Question 10

infraspinatus insertion

Answer 10

middle facet of greater tuberosity of humerus

Question 11

teres minor function

Answer 11

externally/laterally rotate humerus and additional stability (similar to infraspinatus)

Question 12

teres minor origin

Answer 12

lateral border of scapula

Question 13

teres minor insertion

Answer 13

interior facet of greater tuberosity of humerus

Question 14

teres major function

Answer 14

adduction, medial rotator of humerus
assist in extension of arm in abduction

Question 15

teres major origin

Answer 15

lateral border of inferior angle of scapula

Question 16

teres major insertion

Answer 16

medial lip of intertubercular groove of humerus
(adjacent to latissimus dorsi)

Question 17

subscapularis function

Answer 17

internal rotation of humerus, assist in adduction of arm
helps stabilize glenohumeral joint in anterior displacement
only anterior rotator cuff muscle

Question 18

subscapularis origin

Answer 18

subscapular fossa (anterior surface of scapula)

Question 19

subscapularis insertion

Answer 19

lesser tuberosity of humerus (most medial of all rotator cuff insertions)

Question 20

abduction of 0-10 degrees

Answer 20

supraspinatus muscle via suprascapular nerve

Question 21

abduction of 15-110 degrees

Answer 21

abduction to horizontal position is due to deltoid muscle via axilllary nerve

Question 22

abduction 110-180 degeres

Answer 22

raise above horizontal uses scapular rotation by trapezius muscle (via spinal accessory nerve) and serratus anterior (via long thoracic nerve)

Question 23

Jobe/Empty can test

Answer 23

pain or weakness = positive
suggest supraspinatus tendiopathy/tear

Question 24

anterior relations of shoulder joint

Answer 24

subscapularis muscle ccovers anterior aspect, then coracobrachilais and short bicep head

Question 25

posterior relations of shoulder joint

Answer 25

infraspinatus and teres minor muscles cover posterior aspect of joint, long head of triceps runs inferiorly

Question 26

superior relations of shoulder joint

Answer 26

supraspinatus msucle, coracoacromial arch and deltoid muscle lie superior to joint

Question 27

inferior relations of shoulder joint

Answer 27

axillary nerve and posterior circumflex humeral vessels course around surgical neck of humerus, inferiro to joint capsule

Question 28

rotator cuff tears

Answer 28

from repeat overhead motion or acute trauma, include pain, weakness, limited ROM especially overhead

Question 29

shoulder impingement syndrome

Answer 29

compress rotator cuff tendons between humeral head and acromion leads to inflamation, pain, decrease shoulder function specially overhead

Question 30

frozen shoulder

Answer 30

progressive stiffness and loss of shoulder motion Moves through freezing, frozen and thawing stages with varying degrees of pain and limitations

Question 31

glenohumeral instability

Answer 31

excessive humeral head movement in fossa leads to subluxation or dislocation from truama, stress, congenital laxity

Question 32

function of pectoralis major

Answer 32

adduction of humerus, medial rotation of humerus, flexion of humerus, extension of flexed humerus, depression of shoulder girdle

Question 33

pectoralis major heads

Answer 33

clavicular & sternocostal head

Question 34

origin of pectoralis major (clavicular head)

Answer 34

anterior surface of medial half of clavicle

Question 35

origin of pectoralis major (sternocostal head)

Answer 35

anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique

Question 36

insertion of pectoralis major

Answer 36

lateral lip of intertubercular grooce of humerus Fibers twist @ junction, creating superior fibers attach inferiorly and inferior attach superiorly

Question 37

What muscles insert in the intertubercular groove?

Answer 37

latissimus dorsi, pectoralis major, and teres major

Question 38

superficial fascia of pectoral region

Answer 38

vary amount fat and mammary gland, continuous with superficial fascia of neck, abdomen, upper limb

Question 39

pectoral fascia deep

Answer 39

covers pec major, attach to clavicle and continuous with fascia of deltoid & serratus anterior muscles

Question 40

clavipectoral fascia

Answer 40

this is pierced by cephalic vein, thoracoacromial artery, lateral pectoral nerve and lymphatics (CALL) area inferior to pec minor has suspensory ligament of axilla and creates armpit

Question 41

pectoralis minor function

Answer 41

accessory to respiration (elevate ribs when scapula fixed) stabilize scapula (inferiorly and anteriorly agains thoracic wall) assist protraction & downward rotation of scapula

Question 42

pectoralis minor origin

Answer 42

outer surfaces & upper borders of 3-5th ribs costal cartilage

Question 43

pectoralis minor insertion

Answer 43

medial border and superior surface of coracoid process of scapula

Question 44

subclavius function

Answer 44

stabilize sternoclavicular joint in shoulder movement depresses & draw clavicle anteriorly

Question 45

origin of subclavius

Answer 45

junction of first rib and costal cartilage (costochondral junction)

Question 46

insertion of subclavius

Answer 46

groove on inferior surface of middle third clavicle

Question 47

serratus anterior function

Answer 47

protract scapula hold scapula against thoracic wall rotate scapula up during arm abduction assist in forced inspiration when shoulders fixed

Question 48

serratus anterior origin

Answer 48

external surface of upper 8-9 ribs at side of chest well

Question 49

serratus anterior insertion

Answer 49

entire anterior length of medial border of scapula, wrap around inferior angle

Question 50

biceps brachii function

Answer 50

chief supinator

Question 51

biceps brachii insertion

Answer 51

tuberosity of radiuis

Question 52

biceps brachii origin

Answer 52

short head: coracoid process long head: supraglenoid tubercle

Question 53

corachobrachialis function

Answer 53

felx/adduct arm

Question 54

corachobrachialis origin

Answer 54

coracoid processc

Question 55

corachobrachialis insert

Answer 55

medial humerus

Question 56

brachialis function

Answer 56

chief flexor

Question 57

brachialis origin

Answer 57

anteriot humerus

Question 58

brachialis insert

Answer 58

coronoid process & tuberossity of ulna

Question 59

triceps brachii function

Answer 59

chief extensor

Question 60

triceps brachii oroigin

Answer 60

long: infraglenoid tubercle lateral: posterior humerus medial: posterior humerus

Question 61

triceps brachii insertion

Answer 61

proximal end of olecranon

Question 62

aconeus function

Answer 62

extending forarm

Question 63

aconeus origin

Answer 63

lateral epicondyle

Question 64

aconeous insert

Answer 64

lateral olecranon, sup/post ulna