Lecture 16: Arm And Shoulder Flashcards
Label that anterior compartment of the arm
What action do they cause mostly? Secondarily?
What’s their innervation?
What’s their blood supply?
14
Muscles are primarily flexors of forearm at elbow
- Secondarily flexors of arm at shoulder (biceps brachii & coracobrachialis)
- Innervated by musculocutaneous nerve
- Blood supply by brachial artery
Label the superficial veins in the anterior arm slide 4
And be able to label all the slides of the humerus from slides 6-12
H
Label the cadaver picture on slide 16
Hu
Biceps brachii
Origin, insertion etc
Tell me something important about the tendon of the bicep brachii
18
Proximal attachment: Short head: apex of coracoid process of scapula Long head: supraglenoid tubercle of scapula
Distal attachment: Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Innervation: Musculocutaneous nerve
Action: Supinates flexed forearm; flexes forearm at elbow
The tendon of biceps brachii (esp. long head) has the highest rate of spontaneous rupture of any tendon in the body!
> 40 years (= degeneration)
+ rotator cuff injuries
Repetitive lifting
Tell me about the brachialis
19
Proximal attachment: Distal half of anterior humerus
Distal attachment: Coronoid process and tuberosity of ulna
Innervation: Musculocutaneous nerve
Action: Flexes forearm at elbow in all positions
Cobracobrachialis
20
Proximal attachment: Tip of coracoid process of scapula
Distal attachment: Middle third of medial surface of humerus
Innervation: Musculocutaneous nerve
Action: Helps to flex and adduct arm at shoulder
Muscles of the posterior compartment of the forearm What's their main action? What's their blood supply? What's their innervation? Slide 22
- Primarily extensors of the forearm at elbow.
- Blood supply from deep artery of arm (profunda brachii).
- Innervated by radial nerve.
Label the poster compartment slide 24
Triceps brachii slide 25
Then medial head on 26
Proximal attachment Long head: infraglenoid tubercle of scapula [most medial] Lateral head: posterior surface of humerus Medial head: posterior surface of humerus, inferior to radial groove
Distal attachment Proximal end of olecranon of ulna and fascia of forearm
Innervation Radial nerve
Action Extends forearm at elbow; is chief extensor of elbow
Medial head:
Proximal attachment Medial head: posterior surface of humerus, inferior to radial groove
Distal attachment Proximal end of olecranon of ulna and fascia of forearm
Innervation Radial nerve
Action Extends forearm at elbow; is chief extensor of elbow
Anconeus muscle
27
Proximal attachment Lateral epicondyle of humerus
Distal attachment Lateral surface of olecranon and superior part of posterior surface of ulna
Innervation Radial nerve
Action Assists triceps in extending elbow; abducts ulna during pronation
Describe the blood supply of the upper limb
Slide 28 39
Brachial artery supplies anterior arm muscles
Deep brachial artery (profunda brachii) supplies posterior arm muscles
Label slides 30, 31,32
Neurovascular bundle, veins etc
Nervous supply of the arm muscles slide 33, 35 and 36
Has dermatomes too
Musculocutaneous nerve (lateral cord of brachial plexus)
Biceps brachii
Brachialis
Coracobrachialis
Radial nerve (posterior cord of brachial plexus)
Triceps brachii
Anconeus
Posterior forearm
Bones of arm & shoulder comprised of:
Bones of arm & shoulder comprised of:
Pectoral girdle = -> Clavicle -> Scapula
+ Humerus
Label slides of clavicle and scapula on slides 38-42
Do it
What are the joints of the pectoral girdle?
Slide 44
Acromioclavicular joint
• Glenohumeral joint
• Sternoclavicular joint
Acromioclavicular joint slide 45, 47
Type of joint
Type of movement permitted
And types of movement permitted of the scapula slide 46
Synovial plane joint.
• Allows gliding movement as arm is raised and scapula rotates.
• Includes:
• Acromioclavicular joint capsule & ligament
• Coracoclavicular (conoid and trapezoid ligaments)
Describe the glenohumeral joint
What are the functional implications of it’s structure?
Slide 48
Don’t know frand will have to find out
Label the shoulder on slide 49
H
Glenohumeral joint Type of joint? Stabilised by? What movements does it permit Also label the ligaments of the joint on slide 51 and bones on slide 52 and 53
Multi-axial synovial ball and socket joint
- shallow articulation
- most common dislocation joint (95% are anterior
- stabilised by rotator cuff muscles
- permits flexion, extension, abduction, addiction, protraction, retraction, circumduction
Sternoclavicular joint: Type of joint Movement aloud Ligaments between and their action Label the ligaments and everything involved slides 55, 56, 57
Saddle-type synovial joint with articular disc
Saddle-type synovial joint with articular disc
Surrounded by a capsule that allows elevation, depression, protraction, retraction, circumduction
Anterior & posterior sternoclavicular ligaments between clavicle and manubrium
Interclavicular ligament connects the two sternoclavicular joints.
Costoclavicular ligament anchors clavicle to first rib.
Saddle-type synovial joint
Articulation between sternal end of clavicle and manubrium of sternum
Only joint between the superior appendicular and axial skeleton…….
Tell me about the bursae in the shoulder
It’s function and name them
Slide 58
Cushion the joint from overlying muscles, tendons and bones
Subacromial, subdeltoid, subscapular bursae
List the 15 shoulder muscles
Label slide 60
• Deltoid
• Rotator cuff: • Supraspinatus • Infraspinatus • Teres minor • Subscapularis • Teres major • Pectoralis minor & major • Serratus anterior • Subclavius • Trapezius • Latissimus dorsi • Levator scapulae • Rhomboid minor & major Superficial back muscles, deltoid and teres major muscles, rotator cuff muscles and superficial pectoral muscles.
Deltoid muscle
61
Proximal attachment: Inferior edge of scapula spine, lateral margin of acromion, anterior border lateral 1/3 clavicle
Distal attachment: Deltoid tuberosity of humerus
Action: Major abductor of arm; (6) clavicular fibers assist in flexing arm; (2) posterior fibers assist in extending arm.
Innervation: Axillary nerve [C5, C6]
Pectoralis major
Slide 62
Proximal attachment: Clavicular head: anterior surface of medial half of clavicle Sternocostal head: anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle.
Distal attachment: Lateral lip of intertubercular sulcus of humerus
Action: Adduct and medially rotates humerus
Innervation: Lateral and medial pectoral nerves Clavicular head (C5, C6) Sternocostal head (C7, C8, T1)
Pectoralis minor muscle
Slide 63
Proximal attachment:
3rd-5th ribs near costal cartilages
Distal attachment:
Coracoid process of scapula (medial border and superior surface)
Action:
Stabilises scapula by drawing it anteriorly and inferiorly against thoracic wall.
Innervation:
Medial pectoral nerve (C8, T1)
Subclavius muscle
Slide 64
Proximal attachment: Junction of 1st rib and its costal cartilage
Distal attachment: Inferior surface of middle third of clavicle
Action: Anchors & depresses clavicle
Innervation: Nerve to subclavius (C5, C6)
Serratus anterior
Slide 65
Proximal attachment: External surfaces of lateral parts of ribs 1-8
Distal attachment: Anterior (costal) surface of medial border of scapula
Action: Protracts scapula and holds it against thoracic wall; rotates scapula
Innervation: Long thoracic nerve (C5, C6, C7)
Paralysis causing “winged scapula”
“C5,6,7 raises your arms to heaven!”
What are the rotator cuff muscles?
And be able the label the posterior and anterior scapulohumeral muscles on slides 67 and 68
Slide 66
Supraspinous muscle
Slide
Proximal attachment:
Supraspinous fossa of scapula
Distal attachment:
Superior facet on greater tubercle of humerus
Action:
Helps deltoid abduct arm at shoulder & acts with rotator cuff muscles
Innervation: Suprascapular nerve (C4, C5, C6)
Infraspinous muscle
Proximal attachment:
Infraspinous fossa of scapula
Distal attachment:
Middle facet on greater tubercle of humerus
Action:
Laterally rorates arm at shoulder; helps to hold humeral head in glenoid cavity
Innervation: Suprascapular nerve (C5, C6)
Terres minor muscle
71
Proximal attachment:
- Lateral border of scapula
- Distal attachment:
- Inferior facet on greater tubercle of humerus
- Action:
- Laterally rotates arm at shoulder; helps to hold humeral head in glenoid cavity
- Innervation: Axillary nerve (C5, C6)
Subscapularis muscle
Proximal attachment:
Subscapular fossa of scapula
Distal attachment:
Lesser tubercle of humerus
Action:
Medially rotates arm at shoulder and adducts it; helps to hold humeral head in glenoid cavity
Innervation: Upper and lower subscapular nerves (C5, C6, C7)
Tell me some sick shit about rotator cuff injuries
Wear & tear.
- Degeneration of subacromial bursa => degeneration of underlying supraspinatus muscle.
- Tearing of supraspinatus tendon.
- Difficulty in initiating _______________ (movement).
Teres major muscle
74 and 75 and label 76 and 77 and 78
Proximal attachment: Dorsal surface of inferior angle of scapula
Distal attachment: Medial lip of intertubercular groove of humerus
Action: Adducts arm and medially rotates shoulder
Innervation: Lower subscapular nerve (C5, C6)
Muscles acting on the forearm at the elbow joint
Slides 79 and 80
Review questions
1. Which arm muscle flexes at the elbow and is a
powerful supinator?
- Anterior arm muscles are supplied by which
nerve and artery?
- The musculocutaneous nerve lies on the anterior
surface of which muscle?
- Posterior (extensor) muscles are supplied by
which nerve and artery?
- Which dermatome overlies the point of the elbow
(olecranon) ?
- Which arm muscle flexes at the elbow and is a
powerful supinator? - Anterior arm muscles are supplied by which
nerve and artery? - The musculocutaneous nerve lies on the anterior
surface of which muscle? - Posterior (extensor) muscles are supplied by
which nerve and artery? - Which dermatome overlies the point of the elbow
(olecranon)?
Oh dear
