Posterior Triangle

Question 1

Boundries

Answer 1

1. Anterior
2. Posterior
3. Below (base)
4. Above (apex)

Question 2

Anterior

Answer 2

Posterior border sternomastoid

Question 3

Posterior

Answer 3

Anterior border trapezius

Question 4

Base

Answer 4

Middle 1/3 clavicle

Question 5

Apex

Answer 5

Attachment of sternomastoid and trapezius to superior nuchal line of occipital bone

Question 6

Roof

Answer 6

1. Skin
2. Superficial fascia
3. Deep investing fascia

Question 7

Superficial fascia

Answer 7

Contains:
1. Platysma
2. EJV

Question 8

Deep investing fascia

Answer 8

Pierced by:
1. EJV: 1inch above clavicle
2. Cervical plexus cutaneous: at middle of sternomastoid posterior border
3. Supraclavicular nerves: just above clavicle
Spinal root accessory nerve is embedded in it

Question 9

Floor contents

Answer 9

1. Muscles (from below):
   - scalneus medius
   - Levator scapulae
   - splenius capitis
2. Deep (prevertebral) fascia: covering muscles of the floor

Question 10

Contents

Answer 10

1. Muscles
2. Nerves
3. Arteries
4. Veins
5. Lymph nodes

Question 11

Muscles

Answer 11

Inferior belly omohyoid

Question 12

Nerves

Answer 12

1. Trunks of brachial plexus
2. Cutaneous branches of cervical plexus
3. Muscular branches of cervical plexuses
4. Spinal root accessory nerve

Question 13

Arteries

Answer 13

1. 3rd part subclavian artery
2. Suprascapular artery
3. Transverse cervical artery

Question 14

Veins

Answer 14

Lower part EJV

Question 15

Lymph nodes

Answer 15

Along
1. Posterior border sternomastoid
2. Anterior border trapezius
3. Transverse cervical vessels
4. Spinal root of accessory nerve

Question 16

Inferior belly omohyoid

Answer 16

1. Slender muscle
2. 2 1/2 cm above clavicle
3. Divides triangle into:
   - Above: subclavian (supraclavicular)
   - Below: occipital

Question 17

Trunks of brachial plexus

Answer 17

1. Upper
2. Middle
3. Lower
   In lower part triangle

Question 18

Cutaneous branches of cervical plexus

Answer 18

Appear at middle of sternomastoid posterior border and pierce roof deep fascia to supply skin:
1. Lesser occipital (C2)
2. Great auricular (C2,3)
3. Transverse cutaneous nerve neck (C2,3)
4. Supraclavicular (C3,4)

Question 19

Lesser occipital

Answer 19

C2
Ascends along sternomastoid posterior border to skin on scalp back and upper 1/3 of auricle back

Question 20

Great auricular

Answer 20

C2,3
Runs upwards and forwards on sternomastoid to skin on:
1. Parotid
2. Mandible angle
3. Mastoid process
4. Lower 1/3 of auricle lateral surface
5. Lower 2/3 auricle medial surface

Question 21

Transverse cutaneous nerve neck

Answer 21

C2,3
Runs transversely across sternomastoid towards midline and divides into:
1. Upper branch
2. Lower branch
To neck anterior part

Question 22

Supraclavicular

Answer 22

C3,4
Descends as 3 branches which pierce roof deep fascia a little above clavicle then cross clavicle to skin of chest as far as sternal angle and upper 1/2 deltoid

Question 23

Muscular branches of cervical plexus

Answer 23

To
1. Sternomastoid
2. Trapezius
3. Levator scapulae
4. Scalene muscles
5. Diaphragm (phrenic nerve)

Question 24

Spinal root accessory nerve

Answer 24

1. Appears at middle of sternomastoid posterior border
2. Passes downwards and backwards over Levator scapulae (in deep fascia roof) to disappear undercover trapezius (5cm above clavicle
3. Supplies:
   - sternomastoid
   - trapezius

Question 25

3rd part subclavian artery

Answer 25

In lower part of triangle in front of brachial plexus lower trunk

Question 26

Suprascapular artery

Answer 26

1. Branch of thryocervical trunk (1st part subclavian artery) 2. Crosses triangle very close to clavicle

Question 27

Transverse cervical artery

Answer 27

1. Branch of thyrocervical trunk (1st part of subclavian artery) 2. Crosses triangle above Suprascapular artery 3. End at Levator scapulae anterior border by dividing into: - superficial branch - deep branch

Question 28

Lower part EJV

Answer 28

1. Descends in triangle lower part in front of brachial plexus trunks 2. End in subclavian vein 3. Receives: - Suprascapular vein - transverse cervidak vein - anterior jugular vein