Lecture 5: Axilla, Lateral Cervical Triangle

Question 1

Superficial anatomy of the pectoral region

Answer 1

1. Clavicles
2. Sternum: Manubrium (1), Body (2), Xiphoid (3)
3. Ribs
4. Scapula

Question 2

Superficial fascia layers of the neck

Answer 2

1. Platysma
2. Subclavicular nerves
3. Anterior and lateral branches of intercostal nerves

Question 3

Platysma

Answer 3

Superficial muscle that extends from clavicle to jaw line

Question 4

Functions of fascia in pectoral region

Answer 4

1. Defines borders
2. Invests muscles
3. Creates potential spaces
4. Consists of: Superficial layers and Deep layers

Question 5

Contents of the Deltopectoral (clavipectoral) Triangle:

Answer 5

1. Cephalic V
2. Deltopectoral lymph nodes
3. Deltoid branch of thoracoacromial A

Question 6

Borders of the Deltopectoral (clavipectoral) Triangle:

Answer 6

1. Deltoid
2. Pectoralis major
3. Middle 1/3 of clavicle

Question 7

Describe Clavipectoral Fascia

Answer 7

1. Invests subclavius and pectoralis minor
2. Attaches to clavicle and anterior thoracic
   wall

Question 8

What pierces the Clavipectoral fascia?

Answer 8

Cephalic vein, thoracoacromial a., and lateral pectoral nerves pierce it

Question 9

Relationship between the Clavipectoral fascia and suspensory ligament of axilla?

Answer 9

Becomes suspensory ligament of axilla

Question 10

List muscles of the pectoral region, describe their attachments and innervations

Answer 10

Muscles are innervated by
the ventral rami of spinal nerves via
branches of the brachial plexus.

Include:

1. Pectoralis major
2. Pectoralis minor
3. Subclavius
4. Serratus anterior

Question 11

Lists contents of the superficial cervical fascia

Answer 11

1. Platysma muscle
2. Superficial veins
3. Cutaneous nerves

Question 12

Describe the prevertebral fascia and the muscles covered.

Answer 12

Covers:
Muscles of the lateral triangle

Extends:
Around anterior surface of the
cervical vertebrae across anterior
midline.

Question 13

Define the boundaries of the lateral cervical triangle.

Answer 13

Anterior: Posterior border of the sternocleidomastoid (STC)
Posterior: Anterior border of the trapezius
Inferior: Clavicle
Roof: Skin, Superficial layer of deep cervical
fascia (aka investing fascia)

Question 14

List and recognize the muscles of the lateral cervical triangle.

Answer 14

1. Splenius capitis
2. Levator scapulae (LS)
3. Scalenus posterior (SP)
4. Scalenus medius (SM)
5. Scalenus anterior (SA)
6. Omohyoid

Question 15

List vascular and nerve contents of the lateral cervical triangle.

Answer 15

1. Lesser occipital (C2)
2. Supraclavicular (C3,4)
3. Accessory (CN XI):
   • To trapezius and sternocleidomastoid
4. Occipital artery
5. Transverse cervical artery
6. Subclavian vein: (SV)
   • Crosses first rib
7. Subclavian artery: (SA)
   • Crosses first rib
8. External jugular vein (EJV)

Question 16

Describe the origin of the spinal accessory nerve and list muscles innervated.

Answer 16

Spinal root:
• Arises from C1-C5.
• Fibers pass superiorly through foramen magnum and join cranial root.
• innervates: Sternocleidomastoid and Trapezius

Cranial root:
• Arises from medulla

Both roots exit through jugular foramen and separate.

Question 17

Describe the boundaries for the base of the axilla and structures that pass through the axilla.

Answer 17

Base of Axilla (axilla is a pyramid-shaped area)
1. Anterior:
•Pectoralis major muscle
2. Posterior:
•Latissimus dorsi muscle
3. Medial:
•Thoracic wall
4. Lateral:
•Humerus

Question 18

Describe the boundaries for the appex of the axilla and structures that pass through the axilla.

Answer 18

1. Anterior:
• Clavicle
2. Posterior:
• Superior border of the scapula
3. Medial:
• First rib

Question 19

List muscles that make up the posterior and anterior axillary folds.

Answer 19

Anterior axillary fold:
• Pectoralis major

Posterior axillary fold
•Latissimus dorsi
•Teres major

Question 20

Identify the major nerves and vessels in the axilla

Answer 20

Great vessels:
•Axillary vein and artery
•Cephalic vein and basilic vein
•Axillary lymph nodes

Nerves:
•Long thoracic nerve
•Cords of brachial plexus
•Proximal ends of terminal nerves of brachial plexus

Question 21

What makes up the Anterior Wall of the Axilla?

Answer 21

1. clavicle
2. (subclavius)
3. pectoralis major
4. pectoralis minor

Question 22

What makes up the Posterior Wall of the Axilla?

Answer 22

1. scapula
2. subscapularis
3. latissimus dorsi
4. teres majo

Question 23

Lateral Structures of the Axilla?

Answer 23

1. Intertubercular sulcus (bicipital groove)
2. Tendon of long head of biceps
3. Coracobrachialis tendon

Question 24

3 components of the axillary sheath?

Answer 24

Axillary veins, artery, and brachial plexus