The document outlines the triangles of the neck and their boundaries, contents, and deeper structures. It describes the posterior triangle, anterior triangle, and their contents including nerves, vessels, and muscles. The document also details deeper neck structures like the thyroid gland, parathyroid glands, thoracic duct, and branches of the external carotid artery.

1. TRIANGLES OF NECK
OUTLINE
I. TRIANGLES OF
NECK
II. DEEP
STRUCTURES OF
NECK
STERNOCLEIDO-
MASTOID
TO LOCATE STRUCTURES IN NECK ON PATIENT OR
IN PRACTICAL EXAM MOST USEFUL LANDMARK
IS STERNOCLEIDOMASTOID MUSCLE

2. I. TRIANGLES OF NECK
Sternocleidomastoid
Muscle Triangles of Neck –
for description neck
is divided into
anterior & posterior
triangles by
Sternocleidomastoid
Posterior
muscle
triangle
Anterior
triangle

3. A. POSTERIOR TRIANGLE
Anterior -
Sternocleidomastoid 1. Boundaries
Muscle
Superficial cover
- superficial
Posterior fascia, platysma
Trapezius and Investing
Layer
Deep - (floor)
Prevertebral
layer of fascia
Clavicle

4. B. CONTENTS OF POSTERIOR TRIANGLE
Occipital
artery
Superficial -
Great branches of
Auricular n. cervical
Lesser plexus
occipital n. Trans Cerv. n.
Accessory n.
(XI)
External
Jugular Vein
Supra-
clavicular
nerves

5. POSTERIOR TRIANGLE - deeper, saw through
clavicle Nose
Note:
Accessory n. -
divides post.
triangle into
'Carefree' -
superior
'Careful' -
inferior
Phrenic
nerve
Brachial
plexus
roots &
trunks

6. POSTERIOR TRIANGLE - deeper
Brachial
plexus roots &
Phrenic n.
trunks
Transverse
Nose
(superf.)
Cervical A.
Suprascapular
A.
Subclavian
Subclavian a. vein
note: Subclavian vein is not in post triangle

7. B. ANTERIOR TRIANGLE OF NECK
Sternocleidomastoid
Muscle
1. Boundaries-
ant. - midline of neck
post. - sternocleido-
mastoid
superior - mandible
(lower margin).
Midline Subdivided to
of neck smaller triangles (not
required)

8. 2. CONTENTS OF ANTERIOR TRIANGLE OF NECK
In Carotid
sheath:
- cut through
Int. and
sternocleido-
Common
mastoid 2”
Carotid A.,
above
Int. Jug. V.,
sternum
Vagus N.
Follow
dissection Hypoglossal
to all n. XII & ansa
branches of cervicalis
Ext. carotid

9. II. DEEP STRUCTURES OF NECK
A. THYROID GLAND
Two Lateral
Lobes - below
& on sides
thyroid
cartilage
Lateral Lobe Lateral Lobe

10. THYROID GLAND
Right Left Pyramidal lobe-
lateral when present often
lateral
lobe attached to hyoid
lobe bone by fibrous
strand
Isthmus
- located
below
cricoid
cartilage

11. THYROID GLAND - ARTERIAL SUPPLY
a) Sup.
very Thyroid
vascular- artery &
arteries Sup.
accompanied Laryngeal n.
by nerves
b) Inf.
Thyroid
artery &
Recurrent
laryngeal n.
Note: In thyroid surgery care taken not to damage
Recurrent Laryngeal Nerve

12. THYROID GLAND - LOTS OF VEINS
1) Sup. Thyroid vein
follows Sup. Thyroid
artery
2) Middle Thyroid
vein - to Int Jugular
3) Inf. Thyroid vein -
Both sides join at
midline -> L.
Brachiocephalic Vein

13. PARATHYROID GLANDS
- 4 small
bodies (2
on each
side)
Superior located
parathyroid posterior
gland to or
Inferior within
parathyroid Thyroid
gland gland

14. SYMPATHETIC CHAIN
Ant to
vertebrae Sympathetic
Not trunk- deep to
confuse (not in)
with Carotid Sheath
Vagus X
Note: sympathetics
to most of head
are from Superior
Cervical Ganglion

15. THORACIC DUCT
INT. JUGULAR V.
THORACIC DUCT
SUBCLAVIAN V.
DRAINS TO LEFT
BRACHIOCEPHALIC
FOLLOWS LEFT
V.
MARGIN OF
ESOPHAGUS AT JUNCTION OF
SUBCLAVIAN AND
INT. JUGULAR VEINS

16. GUIDE TO DISSECTION
1) Completely Skin Neck
2) Skip p. 175 see:
Prosection Cutaneous
nerves
Do Post. Triangle
3) Cut through clavicle if
not already done
4) Cut through
sternocleidomastoid 2”
(5cm) above sternum p.
178

17. FASCIA OF NECK
Superficial fascia:
- connective
tissue below
dermis
- completely
surrounds neck -
thin and hard to
demonstrate
- contains
Platysma &
Superficial veins

18. POSTERIOR TRIANGLE - CONTENTS
Occipital
artery
Superficial -
Great branches of
Auricular n. cervical
Lesser plexus
occipital n. Trans Cerv. n.
Accessory n.
(XI)
External
Jugular Vein
Supra-
clavicular
nerves

21. POSTERIOR TRIANGLE - deeper, saw through
clavicle Nose
Accessory n.-
divides post.
triangle into
Carefree-
superior
Careful-
inferior Phrenic
nerve
Brachial
plexus
roots &
trunks

22. POSTERIOR TRIANGLE - deeper
Brachial
plexus roots &
Phrenic n.
trunks
Transverse
Nose
(superf.)
Cervical A.
Suprascapular
A.
Subclavian
Subclavian a. vein
note: Subclavian vein is not in post triangle

23. ANTERIOR TRIANGLE OF NECK - CONTENTS
-cut through
Carotid sheath
sternocleido
contents
mastoid 2”
Int. and
above
Common
sternum
Carotid A.,
Int. Jug. V.,
Vagus N. Hypoglossal
n. XII & ansa
Follow cervicalis
dissection to all
branches of ext.
carotid

24. EXTERNAL CAROTID ARTERY
Superficial temporal- Maxillary
scalp & temporalis
Post auricular- post. ear &
scalp
Facial
Occipital- post.
scalp
Ascending pharyngeal-
pharynx
Lingual- tongue
Superior thyroid- br. is Sup
laryngeal

25. PROSECTION
OF
ANTERIOR
NECK

26. INFRAHYOID MUSCLES - all depress hyoid
NOSE
deeper
2) STERNOHYOID 4) THYROHYOID - O -
O- Manubrium & thyroid cartilage; also
clavicle elevates larynx
1) OMOHYOID 3) STERNOTHYROID --
intermediate O - manubrium I -
tendon to thyroid cartilage; also
clavicle, rib 1; depresses larynx
Sup. belly to
hyoid

27. THYROID GLAND - ARTERIAL SUPPLY
Sup. Thyroid
very artery &
vascular- Sup.
arteries Laryngeal n.
accompanied
by nerves Inf. Thyroid
artery &
Recurrent
laryngeal n.
Note: in thyroid surgery care taken not to damage
Recurrent Laryngeal Nerve

28. PROSECTION:
DEEP
DISSECTION OF
NECK