Elbow Joint & Muscles of Proximal Forelimb

Question 1

what does peripheral nervous system supply

Answer 1

supplies the body

cranial nerves –> emerge from brain

spinal nerves –> emerge from spinal cord

Question 2

what is the afferent pathway

Answer 2

body to brain

sensory fibres (pain, temperature, pressure)

proprioception –> location of limb in space

Question 3

what is the efferent pathway

Answer 3

brain to body

voluntary movement

Question 4

how does the nerve supply develop in the embryo

Answer 4

somites in embryo –> blocks of tissue, develop alongside spinal cord, group combines to form each forelimb, drag nerves with them, nerve supply therefore reflects origin

Question 5

what are spinal nerves and where do they pass

Answer 5

leave spinal cord and pass through intervertebral foramen

paired left and right

Question 6

what are the branches of spinal nerves that supply the forelimbs

Answer 6

dorsal branches supply dorsal structures

ventral brances from C6, C7, C8, T1, T2 form brachial plexus

Question 7

what is the brachial plexus

Answer 7

multiple exhanges of fibres –> emerging nerves supply forelimb

Question 8

how are the fibres of skeletal muscle arranged

Answer 8

parallel bundles

encased in fibrous tissue

Question 9

what are the origins and insertions of skeletal muscle usually

Answer 9

O: usually proximal

I: usually distal

Question 10

what are the attachments of skeletal muscle

Answer 10

directly to bone –> rough surface area, bony bumps/tubercles

via aponeurosis (muscle tissue stops but continue on as fibrous tissue) –> sheets, areas of restricted access

via tendons

Question 11

what are tendons

Answer 11

rope of CT

condensation of fibrous tissue into cords

continuation of muscle as fibrous tissue –> less bulky across joints, small area of attachment

Question 12

what are the functions of muscle

Answer 12

muscle fibres contract –> muscle belly shorten

points of attachment pulled closer together –> effect depends on origin and insertion

Question 13

what does action of muscle depend on (2)

Answer 13

1. specific joint(s) crossed
2. aspect of joint(s) crossed

(a muscle has no effect on a joint if it doesn’t cross it)

Question 14

what are extrinsic muscles

Answer 14

origin on axial skeleton –> insertion in appendicular skeleton

Question 15

what movement do extrinsic muscles produce

Answer 15

movement of limb relative to trunk

1. protraction (limb moves cranially)
2. retraction (limb moves caudally)
3. adduction (medually)
4. abduction (laterally)

Question 16

what are intrinsic muscles

Answer 16

original & insertion within appendicular skeleton

movement limited to within lumb (flexion/extension, rotation)

Question 17

what is flexion and extension

Answer 17

flexion - reduced flexor angle (non-weight bearing position)

extension - increased flexor angle (weight bearing position)

Question 18

break down what brachiocephalic means

Answer 18

cephalic = head

brachium = arm

Question 19

what is the origin and insertion of the brachiocephalic muscle

Answer 19

O: cervical vertebrae & skull

I: humerus

Question 20

where is the brachiocephalic muscle located

Answer 20

cranial to limb

Question 21

what is the function of the brachiocephalic muscle

Answer 21

forelimb protractor

shoulder extensor (increases angle caudle to the joint and will extend the shoulder)

Question 22

what is the clavicle

Answer 22

bony remnant in muscle cranial to shoulder

present in cats, absent in dogs

allows differentation on radiographs

Question 23

what muscle is this

Answer 23

brachiocephalic muscle

Question 24

what muscle is this

Answer 24

brachiocephalic muscle

Question 25

what is the latissimus dorsi muscle

Answer 25

latus = broad dorsi = back "broadest muscle of the back"

Question 26

what is the origin and insertion of the latissimus dorsi muscle

Answer 26

O: thoracic vertebrae I: humerus

Question 27

where is the latissimus dorsi located

Answer 27

caudal to the limb

Question 28

what is the function of the latissimus dorsi muscle

Answer 28

forelimb retractor also propulsion shoulder flexor (reduces angle)

Question 29

what muscle is the latissimus dorsi muscle the equal and opposite of

Answer 29

bachiocephalic muscle

Question 30

what muscle is this

Answer 30

latissimus doris

Question 31

what muscle is this

Answer 31

latissimus dorsi

Question 32

what is the origin and insertion of the serratus ventralis muscle

Answer 32

O: thoracic wall (ribs), cervicle vertebrae I: proximal scapula (medial aspect), (proximal to pivitol point)

Question 33

where is the serratus ventralis muscle located

Answer 33

between forelimb and trunk

Question 34

what is the function of serratus ventralis muscle

Answer 34

support weight of trunk between forelimbs cranial portion --\> retractor caudal portion --\> protractor

Question 35

what muscle is this

Answer 35

serratus ventralis muscle

Question 36

what is the origin and insertion of the trapezius muscle

Answer 36

O: cervical and thoracic vertebrae I: proximal scapular spine

Question 37

how many parts does the trapezius muscle have

Answer 37

2 parts - cranial and caudal

Question 38

where is the trapezius muscle located

Answer 38

proximal to limb proximal to pivotal point

Question 39

what is the function of the trapezius muscle

Answer 39

abduction of the limb (also protraction) more limited abduction in domestic species --\> helps with protraction with serratus ventralis

Question 40

what muscle is this

Answer 40

trapezius muscle

Question 41

what muscle is this

Answer 41

trapezius muscle

Question 42

what muscle is this

Answer 42

trapezius muscle

Question 43

what is the origin and insertion of the pectoral muscle

Answer 43

O: sternum I: humerus

Question 44

what are the two pectoral muscles

Answer 44

deep & superficial groups

Question 45

where are the pectoral muscles located

Answer 45

medial to limb distal to pivotal point

Question 46

what is the function of the pectoral muscles

Answer 46

adduction of the limb

Question 47

what muscle is this

Answer 47

pectoral muscles

Question 48

what muscle is this

Answer 48

pectoral muscle

Question 49

what are the extrinsic forelimb muscles and their functions

Answer 49

1. brachiocephalic --\> protractor 2. latissimus dorsi --\> retractor 3. serratus ventralis --\> both protractor & retractor 4. trapezius --\> abductor 5. pectorals --\> adductor

Question 50

what is nerve supply to the extrinsic forelimb muscles

Answer 50

brachiocephalic --\> not brachial plexus the rest are brachial plexus

Question 51

what are the components of the elbow joint

Answer 51

1. trochlea of humerus 2. head of radius 3. trochlear notch of ulna

Question 52

what type of joint is the elbow joint and what does it include

Answer 52

synovial joint including collateral ligaments (humeral epicondyles to radius and ulna)

Question 53

what are the palpable landmarks of the elbow joint

Answer 53

medial & lateral epicondyles olecranon process

Question 54

how is the elbow joint stabilized

Answer 54

1. collateral ligaments 2. anconeal process (ulna) --\> engaged within olecranon/ulnar fossa (humerus)

Question 55

what is the movement of the elbow joint

Answer 55

limited to flexion and extension some rotation possible between radius and ulna

Question 56

what occurs during elbow dislocation

Answer 56

occurs & replaced flexion immobilize in extension (flex limb and realign to put back in

Question 57

what is elbow dysplasia

Answer 57

1. combination of development conditions --\> osteochondrosis, ununited anconeal process (significant for stability), fragmented medial coronoid process, elbow incongruity (articular surfaces don't match eachother) 2. degenerative joint disease --\> classic locations around margins of joint capsule 3. capped elbow --\> subcutaneous bursa

Question 58

what is the origin and insertion of the deltoideus muscle

Answer 58

O: spine of scapula (2 heads) I: lateral aspect of humerus

Question 59

what is the location of the deltoideus muscle

Answer 59

caudo-lateral aspect of limb

Question 60

what is the function of the deltoideus muscle

Answer 60

crosses caudal to shoulder joint --\> shoulder flexor

Question 61

what is the nerve supply to the deltoideus muscle

Answer 61

axillary nerve coming from brachial plexus

Question 62

what muscle is this

Answer 62

deltoideus muscle

Question 63

what is the origin and insertion of the teres major muscle

Answer 63

O: caudal border of scapula I: medial humerus

Question 64

what is the function of the teres major muscle

Answer 64

caudo-medial aspect of limb

Question 65

what is the function of teres major muscle

Answer 65

crosses caudal to shoulder joint --\> shoulder flexor

Question 66

what is the nerve supply of the teres major muscle

Answer 66

axillary nerve

Question 67

what muscle is this (lateral)

Answer 67

teres major muscle

Question 68

what muscle is this

Answer 68

teres major muscle

Question 69

how many heads does the triceps barchii muscle have

Answer 69

4 heads

Question 70

what is the origin of the long head of the triceps brachii muscle

Answer 70

O: caudal border scapula

Question 71

what are the origin of the other heads of the triceps brachii muscle

Answer 71

O: shaft of humerus

Question 72

what is the insertion of the triceps brachii muscle

Answer 72

I: olecranon process of ulna

Question 73

what are the functions of the tricpes brachii muscle

Answer 73

crosses caudal to shoulder --\> shoulder flexor (the long head) crosses caudal to elbow --\> elbow extensor

Question 74

what is the nerve supply of triceps brachii

Answer 74

radial nerve (from brachial plexus)

Question 75

what muscle is this

Answer 75

triceps brachii

Question 76

what muscle is this

Answer 76

triceps brachii

Question 77

what muscle is this (lateral and medial aspect)

Answer 77

triceps brachii

Question 78

what is origin and insertion of the biceps brachii muscle

Answer 78

O: supraglenoid tubercle I: proximal radius (intrinsic muscle)

Question 79

what is the location of the biceps brachii muscle

Answer 79

cranio-medial aspect of limb (deep to brachiocephalicus & pectorals)

Question 80

what is the functions of biceps brachii muscle

Answer 80

crosses cranial to shoulder --\> shoulder extensor crosses cranial to elbow --\> elbow flexor

Question 81

what is the nerve supply to the biceps brachii muscle

Answer 81

musculocutaneous nerve

Question 82

what muscle is this

Answer 82

biceps brachii muscle

Question 83

what muscle is this

Answer 83

biceps brachii muscle

Question 84

what is the tendon of origin of biceps brachii mucsle and how is it held in place and protected

Answer 84

intertubercular groove of humerus held by transverse ligament protected by bicipital bursa (extension of shoulder joint capsule)

Question 85

what is the lacertus fibrosis (insertion, location, function)

Answer 85

fibrous extension of biceps brachii muscle inserts 3rd metacarpal crosses dorsal to carpus carpal extensor --\> allows to stand for long periods of time --\> part of stay apparatus

Question 86

what structure is this

Answer 86

intertubercular groove of humerus yellow - extension of joint capsule blue - transversr ligament

Question 87

what structure is this

Answer 87

lacertus fibrosis

Question 88

what structure is this

Answer 88

lacertus fibrosis

Question 89

what is the origin and insertion of brachialis muscle

Answer 89

O: humerus I: radius

Question 90

what is the location of brachialis

Answer 90

lateral aspect of limb --\> wraps around humerus

Question 91

what is the function of the brachialis muscle

Answer 91

elbow flexor crosses cranial to elbow joint

Question 92

what is the nerve supply of brachialis muscle

Answer 92

musculocutaneous nerve

Question 93

what muscle is this

Answer 93

brachialis muscle

Question 94

what are the shoulder flexor muscles and the nerves that supply

Answer 94

1. latissimus dorsi 2. deltoideus --\> flexor only 3. teres major --\> flexor only (axillary nerve) 4. triceps brachii --\> mult. heads only 1 affects shoulder (radial nerve)

Question 95

what are the shoulder extensor muscles (cranial aspect)

Answer 95

5. brachiocephalicus (cranial direction) 6. biceps brachii (musculocutaneous nerve)

Question 96

name these muscles

Answer 96

1. latissimus dorsi 2. deltoideus 3. teres major 4. triceps brachii 5. brachiocephalicus 6. biceps brachii

Question 97

what gives shoulder collateral support

Answer 97

supraspinatous infraspinatous subscapularis

Question 98

what causes elbow flexion

Answer 98

1. biceps brachii 2. brachialis

Question 99

what causes elbow extension

Answer 99

3. triceps (4 heads)

Question 100

name these muscles

Answer 100

S- supraspinatous I- infraspinatous SubS- subscapularis

Question 101

name these muscles

Answer 101

SubS- subscapularis 1. biceps brachii 3. triceps

Question 102

name these muscles

Answer 102

S- supraspinatous I- infraspinatous 2. brachialis 3. triceps

Question 103

what are the extrinsic muscles

Answer 103

A. brachiocephalic B. latissimus dorsi C. serratus ventralis D. trapezius E. pectorals

Question 105

identify the features of the elbow joint

Answer 105

Question 106

what muscle is this

Answer 106

deltoideus muscle

Question 107

where is the triceps brachii muscle located

Answer 107

caudal aspect of limb

Question 108

name the muscles of the forelimb

Answer 108

Question 109

name the muscles

Answer 109

Question 110

name the muscles