Posterior triangle

Question 1

what is the posterior triangle of the neck also known as?

Answer 1

lateral cervical region

Question 2

anterior border of posterior triangle?

Answer 2

posterior border of SCM

Question 3

posterior border of PT?

Answer 3

anterior border of trapezius

Question 4

inferior border of PT?

Answer 4

middle 1/3 of clavicle

Question 5

what is the posterior triangle covered by?

Answer 5

investing layer of fascia (most superficial)

Question 6

what is the floor of the PT formed by?

Answer 6

prevertebral fascia (deepest)

Question 7

what is a significant muscle in the posterior triangle region?

Answer 7

omohyoid muscle

Question 8

what is the omohyoid muscle split into? by what?

Answer 8

split into 2 bellies by a tendon

Question 9

where does the inferior belly of the omohyoid muscle travel after it crosses the PT?

Answer 9

in an supero-medial direction, splitting the posterior triangle into 2
muscle then crosses under SCM to enter anterior triangle

Question 10

which muscles form the floor of the posterior triangle?

Answer 10

splenius capitis
levator scapulae
anterior, middle and posterior scalene

Question 11

what are the muscles forming the floor of the PT covered by?

Answer 11

prevertebral fascia (deepest)

Question 12

which is the major vein of the neck region?

Answer 12

external jugular vein

Question 13

what is the external jugular vein formed by?

Answer 13

retromandibular and posterior auricular veins

Question 14

where does the EJV lie?

Answer 14

superficially

Question 15

where does the EJV enter the PT?

Answer 15

after crossing the SCM

Question 16

what happens within the PT in terms of the EJV?

Answer 16

EJV pierces the investing layer of fascia (superficial deep)

Question 17

where does EJV empty into after piercing investing layer of fascia?

Answer 17

subclavian vein

Question 18

what is the subclavian vein normally used as?

Answer 18

a point of access to venous system via central catheter

Question 19

which veins aside from EJV also lie in PT?

Answer 19

transverse cervical

suprascapular veins

Question 20

what are subclavian, transverse cervical and suprascapular veins accompanied by in the PT?

Answer 20

their respective arteries

Question 21

which part of the subclavian artery can be located? how?

Answer 21

distal part of subclavian artery

it emerges between the anterior and middle scalene muscles

Question 22

where does the subclavian artery end?

Answer 22

crosses the 1st rib

becomes axillary artery - supplies upper limb

Question 23

clinical: why is the EJV vulnerable to damage?

Answer 23

has relatively superficial course down the neck

Question 24

clinical: what happens if the EJV is severed? in what injury?

Answer 24

injury e.g. knife slash

lumen held open

Question 25

clinical: why is lumen of EJV held open in severance?

Answer 25

due to thick layer of investing fascia, air will be drawn into vein

Question 26

clinical: what does lumen of EJV being held open in severance produce?

Answer 26

cyanosis | can stop blood flow through the right atrium

Question 27

clinical: how do you manage severance of the EJV?

Answer 27

medical emergency | application of pressure to the wound, stopping bleeding and entry of air

Question 28

which nerve runs through the PT?

Answer 28

accessory nerve (CN XI)

Question 29

how does the accessory nerve (CN XI) enter the PT?

Answer 29

exits the cranial cavity, descends down the neck, innervates SCM and enters the posterior triangle in an oblique, inferoposterior direction

Question 30

where does the accessory nerve (CN XI) travel as it enters the PT?

Answer 30

within the investing layer of fascia | relatively superficial in PT - vulnerable to injury

Question 31

what forms within the muscles of the floor of the PT?

Answer 31

cervical plexus

Question 32

what is a major branch of the cervical plexus?

Answer 32

phrenic nerve

Question 33

where does phrenic nerve arise?

Answer 33

anterior division of spinal nerves (C3-C5)

Question 34

where does phrenic nerve travel?

Answer 34

descends down the neck, within the prevertebral fascia (deepest)

Question 35

what does the phrenic nerve innervate?

Answer 35

diaphragm

Question 36

what do other branches of the cervical plexus innervate?

Answer 36

the vertebral muscles | provide cutaneous innervation to parts of the neck and scalp

Question 37

what else crosses the floor of the posterior triangle?

Answer 37

trunks of the brachial plexus

Question 38

clinical: for anaesthesia of the neck area, which nerve block is used?

Answer 38

cervical plexus block

Question 39

clinical: where is the anaesthetic injected in a cervical plexus block?

Answer 39

injected along the posterior border of SCM at junction of its superior and middle 1/3s

Question 40

what is significant about the superior and middle 1/3 of the SCM?

Answer 40

junction where the cutaneous branches of the cervical plexus emerge - nerve point of the neck

Question 41

in which patients is a cervical nerve block not carried out? why?

Answer 41

patients with pulmonary or cardiac problems | runs a high risk of damaging phrenic nerve

Question 42

which structure subdivides the PT?

Answer 42

omohyoid muscle | splits PT into 2 regions

Question 43

what are the 2 regions of the PT divided by omohyoid muscle?

Answer 43

occipital and subclavian triangle

Question 44

which part is the occipital triangle?

Answer 44

larger, superior part

Question 45

which is the subclavian triangle?

Answer 45

inferior triangle of PT

Question 46

what does the subclavian triangle contain?

Answer 46

distal portion of subclavian artery