3.2- Brachia and Pectral Girdle: Muscles, Nerves, and Blood Vessels

Question 1

Describe the articular surfaces, ligaments, bursae, classification, planes, and movements of the Glenohumeral Joint

Answer 1

• Glenohumeral Joint
  
  • Glenoid cavity of sternum with head of humerus
  • Synovial ball and socket
  • Multiaxial
  • Movements: Medial/Lateral Rotation, Flexion/Extension, Abduction/Adduction

Question 2

Describe the articular surfaces, ligaments, bursae, classification, planes, and movements of the Elbow Joint

Answer 2

• Uniaxial
• Movements: Flexion/Extension
• Ligaments
  
  • Collateral Ligaments- Prevent abduction/adduction
    
    • Medial Collateral Ligament- Humerus’ medial epicondyle à ulna’s coronoid process and olecranon
    • Lateral Collateral Ligament- Humerus’ lateral epicondyle à annular ligament
  • Other Ligaments
    
    • Annular Ligament- Ulna’s radial notch à wraps around radial head à proximal radioulnar joint
      
      • Forms a sling around neck of radius
      • Keeps radial head stable at the capitulum
• Bursae- Multiple bursae. Most importantly, subtendnous bursa between ulna’s olecranon and the triceps brachii tendons, reducing friction during elbow flexion/extension
• Elbow Joint- Synovial hinge
  
  • Humero-Radial Joint
    
    • Synovial hinge
    • Flexion/extension
    • Radius head with humerus’ capitulum
  • Humero-Ulnar Joint
    
    • Synovial hinge
    • Flexion/extension
    • Ulna’s trochlear notch with humerus’ trochlea
• Proximal Radioulnar Joint-
  
  • Shares the elbow joint cavity but is not part of the elbow joint
  • Synovial pivot
  • Pronation/Supination
  • Radius head with radial notch of ulna

Question 3

Describe the movements of the scapula and the muscles that make the movement possible

Answer 3

• The scapula doesn’t really a proper synovial/cartilaginous/fibrous joint, it has more of a functional joint
• The scapula glides over the ribs
• Movements
  
  • Elevation
    
    • Superior section of trapezius
    • Levator scapula
  • Depression
    
    • Inferior section of trapezius
  • Protraction/Abduction- Move anteriorly away from vertebrae
    
    • Pectoralis minor
    • Serratus anterior
  • Retraction/Adduction- Move posteriorly towards vertebrae
    
    • Rhomboid
  • Lateral Rotation- Inferior angle moving out laterally
  • Medial Rotation- Inferior angle moving in medially

Question 4

Describe the location, action, and innervation of the trapezius

Answer 4

See table in notes for answer

Question 5

Describe the location, action, and innervation of the levator scapula

Answer 5

See table in notes for answer

Question 6

Describe the location, action, and innervation of the rhomboid minor

Answer 6

See table in notes

Question 7

Describe the location, action, and innervation of the rhomboid major

Question 8

Describe the location, action, and innervation of the supraspinatus

Answer 8

See notes

Question 9

Describe the location, action, and innervation of the infraspinatus

Answer 9

See notes

Question 10

Describe the location, action, and innervation of the teres minor

Answer 10

See notes

Question 11

Describe the location, action, and innervation of the subscapularis

Answer 11

See notes

Question 12

Describe the location, action, and innervation of the teres major

Answer 12

See notes

Question 13

Describe the location, structure, action, innervation, and blood supply of the biceps brachii

Answer 13

See notes

Question 14

Describe the location, structure, action, innervation, and blood supply of the brachialis

Answer 14

See notes

Question 15

Describe the location, structure, action, innervation, and blood supply of the coracobrachialis

Answer 15

See notes

Question 16

Describe the location, structure, action, innervation, and blood supply of the pectoralis major

Answer 16

See notes

Question 17

Describe the location, structure, action, innervation, and blood supply of the deltoid

Answer 17

See notes

Question 18

Describe the location, structure, action, innervation, and blood supply of the triceps brachii

Question 19

Label diagram

Answer 19

Question 20

Label diagram

Answer 20

Question 21

Label diagram

Answer 21

Question 22

Label diagram

Answer 22

Question 23

Label diagram

Answer 23

Question 24

Label diagram

Answer 24

Question 25

Label diagram

Answer 25

Question 26

Label diagram

Answer 26

Question 27

Label diagram

Answer 27

Question 28

Describe the arteries and veins of the anterior brachia, antebrachia, and hand. Draw a diagram to assist your explanation.

Answer 28

The brachia/upper-limb has a single major artery supplying the upper limb
This artery has different names depending on where it is

Both radial and ulnar arteries originate in the brachial artery which divides at the neck of the radius

• SUBCLAVICAL
  Heartà Lateral Side of 1^st Rib
  
  • Artery: Subclavian Artery
  • Veins:
    
    • At heart: Superior Vena Cava
    • Just superior to heart: Brachiocephalic Vein
    • Prior to medial side of 1^st rib: Subclavian Veins
• AXILLARY
  Lateral Side of 1^st Ribà Inferior Border of Teres Major
  Axillary = Armpit
  
  • Artery: Axillary Artery
  • Veins:
    
    • Deep Veins: Axillary Veins
    • Superficial Veins: Cephalic drains into distal axillary veins. Basilic already drained into proximal brachial veins.
      
      • DISTALLY: Cephalic Superficial Vein à drains into the distal axillary veins
• BRACHIAL
  Inferior Border of Teres Majorà Neck of Radius
  Brachial = Brachia = Upper Arm
  
  • Artery: Divide into the ulna and radial arteries at the neck of the radius
    
    • Brachial Artery
  • Veins:
    
    • Deep Veins: Brachial Veins x2
    • Superficial Veins: Basciic drains into proximal brachial veins
      
      • Basilic Superficial Vein à drains into the proximal brachial veins
      • Cephalic Superficial Vein à drains into the distal axillary veins
• ULNA AND RADIAL
  Neck of Radiusà Wrist
  Ulna = Along Ulna
  Radius = Along Radius
  
  • Arteries: Brachial Artery drains into the ulna and radial arteries which then divide into the deep and superficial palmer arterial arches
    
    • Ulna Artery- Moves down the radius, lateral to flexor carpi radialis muscle
    • Radial Artery- Moves down the ulna, medial to flexor carpi ulna muscle
  • Veins:
    
    • Deep Veins:
      
      • Ulna Veins x2
      • Radial Veins x2
    • Superficial Veins: Both originate from dorsal venous arch
      
      • Basilic Superficial Vein
      • Cephalic Superficial Vein
• PALMAR ARCHES
  Wrist Onwards
  
  • Arteries: Originate from the ulna and radial arteries
    
    • Deep Palmer Arterial Arch
    • Superficial Palmer Arterial Arch
  • Veins:
    
    • Deep Veins: Divide into the two ulna veins and two radial veins
      
      • Deep Venous Arch x2
      • Superficial Venous Arch x2
    • Superficial Veins: Divides into the basilic and cephalic superficial veins
      
      • Dorsal Venous Arch

Question 29

Describe the ligaments of the glenohumeral joint

Answer 29

• Glenohumeral Joint- Glenoid cavity of sternum with head of humerus
  
  • Synovial ball and socket
  • Articular Surfaces: Glenoid cavity of sternum with head of humerus
    
    • Aided by the fibrocartilaginous glenoid labrum, a fibrocartilaginous ring between glenoid cavity and humeral head increasing stability of the joint
  • Ligaments: Provide stability, but are relatively weak to enable mobility
    
    • Glenohumeral Ligament- Between scapula’s glenoid cavity and anatomical neck of humerus
    • Coracoacromial- Between scapula’s coracoid process and scapula’s acromion
    • Coracoclavicular- Between scapula’s coracoid process and the clavicle
    • Also stabilised by the rotator cuff muscles: Subscapularis, supraspinatus, and infraspinatus
  • Bursae: Multiple bursae, most importantly the subacromial bursa between scapula’s acromion and the supraspinatus muscle

Question 30

Name the bursae of the glenohumeral joint. Where is it found?

Answer 30

• Glenohumeral Joint- Glenoid cavity of sternum with head of humerus
  
  • Synovial ball and socket
  • Articular Surfaces: Glenoid cavity of sternum with head of humerus
    
    • Aided by the fibrocartilaginous glenoid labrum, a fibrocartilaginous ring between glenoid cavity and humeral head increasing stability of the joint
  • Ligaments: Provide stability, but are relatively weak to enable mobility
    
    • Glenohumeral Ligament- Between scapula’s glenoid cavity and anatomical neck of humerus
    • Coracoacromial- Between scapula’s coracoid process and scapula’s acromion
    • Coracoclavicular- Between scapula’s coracoid process and the clavicle
    • Also stabilised by the rotator cuff muscles: Subscapularis, supraspinatus, and infraspinatus
  • Bursae: Multiple bursae, most importantly the subacromial bursa between scapula’s acromion and the supraspinatus muscle

Question 32

Describe the joints of the ulna and radius, including

• Articular surfaces
• Ligaments
• Bursae
• Classification
• Movements/Function

Answer 32

Elbow- Synovial Hinge

• Uniaxial
• Movements: Flexion/Extension
• Ligaments
  
  • Collateral Ligaments- Prevent abduction/adduction
    
    • Medial Collateral Ligament- Humerus’ medial epicondyle à ulna’s coronoid process and olecranon
    • Lateral Collateral Ligament- Humerus’ lateral epicondyle à annular ligament
  • Other Ligaments
    
    • Annular Ligament- Ulna’s radial notch à wraps around radial head à proximal radioulnar joint
      
      • Forms a sling around neck of radius
      • Keeps radial head stable at the capitulum
• Bursae- Multiple bursae. Most importantly, subtendnous bursa between ulna’s olecranon and the triceps brachii tendons, reducing friction during elbow flexion/extension
• Elbow Joint- Synovial hinge
  
  • Humero-Radial Joint
    
    • Synovial hinge
    • Flexion/extension
    • Radius head with humerus’ capitulum
  • Humero-Ulnar Joint
    
    • Synovial hinge
    • Flexion/extension
    • Ulna’s trochlear notch with humerus’ trochlea
• Proximal Radioulnar Joint-
  
  • Shares the elbow joint cavity but is not part of the elbow joint
  • Synovial pivot
  • Pronation/Supination
  • Radius head with radial notch of ulna

Proximal Radioulnar and Distal Radioulnar

• Shares the elbow joint cavity but is not part of the elbow joint
• Type: Synovial pivot
• Axes: Uniaxial
• Movement: Pronation/Supination
  
  • Assisted by a fibrous syndesmosis joint (an interosseous membrane) between the radius and ulna that ensures they move together
• Components:
  
  • Proximal Radioulnar: Radius head with radial notch of ulna
  • Distal Radioulnar: Ulna head with ulnar notch of radius

Radioulnar Joint

• An interosseous membrane running between the radius and ulna
• Type: Fibrous Syndesmoses
• Function:
  
  • Ensures that the radius and ulna move together, assisting the proximal and distal radioulnar joints, enabling pronation and supination
  • A point of muscle attachment
• Components:
  
  • Medial side of radius shaft and lateral side of ulna shaft