S7: the spine (2)

Question 1

Describe the characteristic features of cervical vertebrae, including the atypical cervical vertebrae

Answer 1

C1, C2 & C7 are atypical vertebrae, whilst C3-6 are typical vertebrae
Characteristics of typical vertebrae include bifid spinous process, transverse foramen in the transverse process, body that is small & broad from side to side
C1 atlas = does not have a vertebral body or spinous process
C2 axis = strongest cervical vertebrae & large spinous process, odontoid process projects vertically upwards from the body of the axis
C7 vertebra prominens = longest spinous process, which is not bifid, foramen transversarium only transmits the accessory vertebral veins

Question 2

Describe the characteristic features of thoracic vertebrae and their articulation with the ribs

Answer 2

Characteristics of thoracic vertebrae include medium-size, heart shaped vertebral bodies, vertebral foramen is small & circular, long spinous processes
Limited flexibility compared to cervical & lumbar spine because rib cage is connected to each segment of the thoracic spine

Question 3

List the muscles in the pectoral region

Answer 3

Pectoralis major
Pectoralis minor
Subclavius
Serratus anterior

Question 4

Name the origin, insertion, action and innervation of pectoralis major

Answer 4

Sternal head = origin: anterior surface of sternum, upper 6 coastal cartilages, aponeurosis of external oblique muscle
Clavicular head = origin: anterior surface of medial clavicle
Both insert in the intertubercular sulcus of the humerus
Innervation = medial pectoral nerve & lateral pectoral nerve
Action = adduction of arm, arm flexion at shoulder joint & medial rotation

Question 5

Name the origin, insertion, action and innervation of pectoralis minor

Answer 5

Origin = 3rd to 5th ribs
Insertion = coracoid process of the scapula 
Innervation = medial pectoral nerve 
Action = stabilises the scapula by drawing it anteroinferiorly against the thoracic wall

Question 6

Name the origin, insertion, action and innervation of subclavius

Answer 6

Origin = from the junction of the 1st rib and its coastal cartilage 
Insertion = inferior surface of the middle third of the clavicle 
Innervation = nerve to subclavius 
Action = anchors & depresses the clavicle

Question 7

Name the origin, insertion, action and innervation of serratus anterior

Answer 7

Origin = lateral aspects of ribs 1-8
Insertion = medial border of the scapula 
Innervation = long thoracic nerve 
Action = protraction, abduction above 90 degrees, holds scapula against the ribcage

Question 8

Describe the four borders of the axilla

Answer 8

Lateral border = intertubercular sulcus of the humerus
Medial border = serratus anterior, ribs & intercoastal muscles
Anterior border = pectoralis major, pectoralis minor & subclavius
Posterior border = subscapularis, teres major & latissimus dorsi

Question 9

What are the contents of the axilla?

Answer 9

Axillary artery & vein
Cords of the brachial plexus 
Branches of the brachial plexus 
Intercostobrachial nerve 
Axillary lymph nodes

Question 10

List the 6 groups of axillary lymph nodes

Answer 10

Anterior
Posterior
Lateral
Central 
Infraclavicular 
Apical 
MNEMONIC = APICAL

Question 11

Describe axillary lymph node dissection

Answer 11

Often performed as part of the staging of breast cancers
Can result in lymphoedema = accumulated lymph in the subcutaneous tissue leads to painful swelling of upper limb
Risk of damage to either the long thoracic nerve or the thoracodorsal nerve