Lecture 17: Skeletal Muscles III Upper Limb

Question 1

what muscle is shown in this anterior view.
describe origin, insertion, fxn, and innervation?

Answer 1

1. lesser tubercle of humerus
2. subscapularis
   o: subscapular fossa
   i: lesser tubercle of humerus
   fxn: medial rotation of shoulder
   nerve: brachial plexus

Question 2

what are the 3 subdivisions of shoulder area?

Answer 2

pectoral, deltoid, and scapular

Question 3

label

Answer 3

1. spine of scapula
2. supraspinatus
3. greater tubercle of humerus
4. infraspinatus

Question 4

supraspinatus

describe origin, insertion, fxn, and innervation?

Answer 4

o: supraspinous fossa
i: greater tubercle of humerus
fxn: first 30 degrees of abduction of shoulder
nerve: brachial plexus

Question 5

infraspinatus

describe origin, insertion, fxn, and innervation?

Answer 5

o: infraspinous fossa
i: greater tubercle of humerus
fxn: lateral rotation of shoulder
nerve: brachial plexus

Question 6

deltoid

describe origin, insertion, fxn, and innervation?

Answer 6

o: clavicle, acromion, spine of scapula
i: fibers converge towards boney elevation on lateral surface of the shaft of humerus (deltoid tuberosity)

fxn: abduction of shoulder: 30 to 90 degrees
nerve: axillary branch of brachial plexus

Question 7

Answer 7

1. deltoid
2. clavicle

Question 8

what is the prime mover for lateral rotation?

Answer 8

infraspinatus

Question 9

what is the prime mover for medial rotation?

Answer 9

subscapularis

Question 10

what separates the posterior and anterior arm?

Answer 10

intermuscular septum= dense connective tissue

Question 11

anterior arm
what is the general fxn and innervation?

Answer 11

fxn: flexion of elbow/shoulder
muscular cutaneous nerve

Question 12

posterior arm
what is the general fxn and innervation?

Answer 12

fxn: extension elbow
radial nerve

Question 13

Biceps Brachii

describe origin, insertion, fxn, and innervation?

Answer 13

long head
o: right above glenoid fossa; supraglenoid tubercle of scapula
i: radial tuberosity

short head
o:coracoid process
i: radial tuberosity

fxn: supination(main fx)
flexion of shoulder and elbow

muscular cutaneous nerve

Question 14

what is the prime mover of supination of forearm?

Answer 14

biceps brachii

Question 15

what is the prime mover of flexion of elbow?

Answer 15

brachialis

Question 16

brachialis

describe origin, insertion, fxn, and innervation?

Answer 16

o: shaft/body of humerus
i: ulna tuberosity

flexion of elbow
muscular cutaneuous nerve

Question 17

triceps brachii

describe origin, insertion, fxn, and innervation?

Answer 17

lateral head
o: lateral shaft of humerus

long head
o: right below glenoid; infraglenoid scapula

medial head
o: medial shaft humerus

i: olecranon process
fxn: extension of elbow
radial nerve

Question 18

Answer 18

brachialis

Question 19

what muscle is this? name the components?

Answer 19

biceps brachii
1. long head
2. short head

Question 20

prime mover extension elbow

Answer 20

triceps brachii

Question 21

what are two compartments of forearm

Answer 21

anterior: flexor wrist, fingers
posterior: extensor wrist, fingers

Question 22

Pronator teres
origin/insertion/fxn/nerve

Answer 22

superficial
origin:medial epicondyle
insert: shaft radius
fxn: pronation forearm
nerve: median

Question 23

flexor carpi radialis
origin/insertion/fxn/nerve

Answer 23

superficial
origin: medial epicondyle
insert: 2nd and 3rd metacarpal bones
fxn: flexion wrist/elbow
nerve: median nerve

Question 24

what is flexor retinaculum

Answer 24

a fibrous connective tissue band that forms the anterior roof of the carpal tunnel

holds tendons in place

Question 25

which muscles are part of the anterior superficial forearm

Answer 25

pronator teres flexor carpi radialis

Question 26

what compartment of forearm muscle does brachioradialis belong to

Answer 26

posterior compartment due to innervation; radial nerve

Question 27

brachioradialis origin/insertion/fxn/nerve

Answer 27

superficial o: lateral epicondyle of humerus i: styloid process of radius helps with flexion of forearm at the elbow radial nerve

Question 28

Answer 28

brachioradialis

Question 29

extensor carpi ulnaris fxn/origin/insertion/innervation what compartment

Answer 29

posterior (superficial) origin: lateral epicondyle insert: 5th metacarpal bone fxn: extensor of wrist and ulnar deviation nerve: radial

Question 30

extensor digitorum describe fxn/origin/insertion/innervation what compartment

Answer 30

posterior (superficial) fxn: extension digits **prime mover for extension wrist and all joints of digits origin: common extensor tendon insert: middle/distal phalanges of medial 4 digits nerve: radial

Question 31

prime mover extension wrist and digits

Answer 31

extensor digitorum

Question 32

label. what compartment?

Answer 32

left= extensor carpi ulnaris right= extensor digitorum superficial layer posterior compartment

Question 33

describe fxn/origin/insertion/nerve of supinator? what compartment is it

Answer 33

fxn: supinates forearm origin: ulna insert: shaft radius nerve: radial posterior, deep

Question 34

describe fxn/origin/insertion/nerve of extensor pollicis longus? what compartment is it

Answer 34

fxn: extend thumb (prime mover) origin: shaft ulna insert: distal phalanx thumb nerve: radial posterior, deep

Question 35

what is prime mover extension thumb

Answer 35

extensor pollicis longus

Question 36

label. what compartment?

Answer 36

top= supinator bottom= extensor pollicis longus deep layer, posterior compartment of forearm

Question 37

describe thumb adduction and abduction. what plane is it in?

Answer 37

sagittal. note: thumb is not in same plane as other fingers

Question 38

describe thumb flexion/extension/ what plane?

Answer 38

coronal

Question 39

what are the three groups hand muscles are divided into

Answer 39

thenar hypothenar central

Question 40

describe thenar group

Answer 40

bulge at base of thumb origin: carpal bones insert: 1st metacarpal, middle & distal phalanges of thumb fxn: flexion, abduction, opposition of thumb nerve: median

Question 41

describe hypothenar group

Answer 41

bulge base of 5th finger origin: carpal bones insert: 5th metacarpal and phalanges of 5th finger fxn: flexion, abduction, opposition 5th finger nerve: ulnar

Question 42

describe lumbricals

Answer 42

4 muscles, part of central group origin: tendons of FDP insert: indirectly to middle and distal phalanges of digits 2-5 fxn: flexion metacarpal phalangeal and extension of PIP/DIP nerve; medial and ulnar

Question 43

Answer 43

thenar group hypothenar group lumbricals

Question 44

what muscles are these? what group? describe origin, insertion, fxn, nerve

Answer 44

left= palmar interossei fxn: adduction digits “PAD” right= dorsal interosseir fxn: abduction digits “DAB” origin: metacarpal bones insert: indirectly to Middle and distal phalanges of digits nerve: ulnar

Question 45

which nerve supplies most of intrinsic muscles of hand?

Answer 45

ulnar

Question 46

describe axilla

Answer 46

transitional area btw head/neck/chest and upper limb (axillary artery and vein and cords of the brachial plexus pass thru)

Question 47

what is cubital fossa

Answer 47

transitional area btw arm and forearm The median and radial nerves as well as brachial artery are the main contents of this fossa.

Question 48

label. what are these?

Answer 48

axilla cubital fossa carpal tunnel =transitional areas

Question 49

what is this

Answer 49

The carpal tunnel is a fibro-osseous tunnel made by the carpal bones and the thickening of the deep fascia, the flexor retinaculum, in front of the wrist joint This tunnel contains the tendons of flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus muscles as well as median nerve