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Ppt of anatomy of neck & ML imp
1. Anatomy of Neck & its
Medicolegal importance.
Presenter Dr Gopal G Hargi
PG in FM& T
2. Neck is a very prominent & vital part .Even
trivial injuries can cause death without
showing any signs. There are very vital
structures in a relatively small & unprotected
anatomic region making it very vulnerable to
fatal injuries.
Moreover the Neck is an area which can be
easily grasped and immobilized
5. Lower border of mandible lies b/w C2 & C3.
The front of the lower pharynx & upper
oesophagus lie the larynx & trachea.
On each side of the pharynx is the carotid
sheath,containing the common & internal
carotid arteries & the IJV with the cervical
sympathetic trunk behind it.
The Platysma –a broad flat sheet of muscle
lies superficial to the layers of fascia.
6. Coll’s fascia :The space among the structures of
neck are filled with loose areolar tissue.The
structures of the neck are mostly supplied to move
up & down
.This fascia is a laminar condensation of loose
areolar tissue in neck produced by the movements
of these structures.
These laminar condensations take different names
in different regions & are continuous with each
other or indirectly.
These loose areolar tissue form sheaths which
enclose muscles and their moving structures
7. MODIFICATIONS/
LAMINAE/EXTENSIONS OF DEEP
CERVICAL FASCIA
HAS 7 MODIFICATIONS
1. INVESTING LAYER
2. PRETRACHEAL LAYER
3. PREVERTEBRAL LAYER
4. CAROTID SHEATH
5. BUCCOPHARYNGEAL FASCIA
6. TEMPORAL FASCIA
7. PHARYNGOBASILAR FASCIA
8.
9. INVESTING LAYER
ATTATCHMENTS
ABOVE- EXTERNAL OCCIPITAL PROTUBERANCE,MASTOID PROCESS, EXTERNAL ACOUSTIC
MEATUS, BASE OF THE MANDIBLE
BELOW- SPINE OF SCAPULA, ACROMION PROCESS, CLAVICLE, MANUBRIUM STERNI
FRONT- HYOID BONE & CONTINUOUS WITH THE FASCIA OF THE FASCIA OF THE OPPOSITE
SIDE
BEHIND- 7TH CERVICAL VERTEBRA, LIGAMENTUM NUCHAE
10.
11. CCA ,arises from the left side of AOA.
It lies in the medial part of carotid sheath .
Upper border of C4 the CCA bifurcates.
The carotid pulse can be felt by pressing against
the anterior tubercle of the tranverse process of
C6 vertebra.
ICA ,at its commencment there is a bulge ,
here the arterial wall is thin & contains the
baroreceptors which is supplied by the 9th & 10th
nerves which control the CVS .
carotid body is a small structure behind the
bifurcation of CCA & contains baroreceptors which
maintain oxygen saturation.
12.
13. IJV forms a jugular arch in the suprasternal
space i.e between the sternal & clavicular
head of sternocleadomastoid tendon.
Larynx lies below the hyoid bone in the
midline of the neck at the level of C4-C6
vertebra.
14. The AJV commences beneath the chin & passes
downwards ,side by side beneath the platysma to
the suprasternal region.Here they pierce the deep
fascia & come to lie in the suprasternal space.
Carotid sheath consists of a network of areolar
tissue that surrounds the carotid
arteries(c&i),IJV,Vagus nerve & some deep cervical
lymph nodes.
It is thin where it overlies the IJV ,allowing the
vein to dilate during increased blood flow.
15.
16. The thyroid gland is situated low down at the front
of the neck.The 2 symmetrical lobes are connected
by isthmus which lie in front of 2nd,3rd & 4th
tracheal rings.
Trachea begins at the level of C6 vertebra in
continuity of the larynx,The cervical part lies in
the midline of the neck ,in contact with the front
of the oesophagus.
Oesophagus commences in continuity with the
pharynx at the level of lower border of the cricoid
cartilage(C6).
17.
18. Hyoid bone lies free ,suspended by muscles & so
very mobile .Above its attached to floor of mouth &
tongue,larynx below,behind to epiglottis &
pharynx.It lies at the level of C3 vertebra.
Vertebral artery arises from subclavian artery &
passes up to traverse the foramen of transverse
process of upper 6 cervical vertebras.On emerging
from foramen the artery enters the skull through
foramen magnum
.It pierces the spinal dura mater & archnoid and at
the lower border of pons forms the basillar artery.
19.
20.
21.
22. For judging the severity of the injuries to the neck
its divided into 3 zones.
Zone I
• highest mortality
Zone II
• most frequent site of injury
• lower mortality
Zone III
• neurological
• distal carotids
• pharyngeal injuries
24. (Zone 1)Thoracic inlet (clavicle)to cricoid
cartilage
significant injury in the zone I region may be hidden
from inspection of the chest or the mediastinum.
subclavian vessels
brachiocephalic veins
common carotid artery
jugular vein
aortic arch
Trachea
esophagus
Lung apices
c spine
spinal cord
CN roots
25. Zone 2
Carotid and vertebral
arteries
jugular veins
pharynx
larynx
trachea
esophagus
c spine
spinal cord
Cricoid cartilage to angle of mandible
26. Zone 3
Salivary glands
parotid gland
esophagus
trachea
c spine
Carotid arteries
jugular veins
CN IX - XII
Angle of mandible to base of skull
27. Injury above the level of C4 –rapid death
Due to disruption of CV centre.
Causes- Hyperextension & hyperflexion
Atlanto-occipital injury---fatal: widening of space
with some blood palpated as ‘loosening ‘
Of the junction with widening.Severe form the
articulating condyles of atlas can be seen within
foraen magnum.
C1-C2 injury-- neurogenic shock ,odontoin is #
C2-C3 #( HANGMAN #) rapid
28. Injuries over the region of neck
A) Homicidal:
a)strangulation
i)Ligature ii) Manual
c)bansdola
e)mugging
f)penetrating injuries
a) knife b) gunshot
g)cut throat injuries
h)blunt force impact
i) homicidal ii) accidental
29. Blunt force impact to the side of neck
Shearing
excessive rotation/ hyperextension
◦ distention and stretching
Tearing of Vertebral Artery
The carotids too get dissected ,veins damaged
Blood tracks along upper part of vessel & enters
the cranial cavity producing massive SAH
.
30. Impact Anterior Neck
Impact Anterior Neck
Crush larynx or trachea; cricoid ring
compress esophagus against spinal column
sudden increased intratracheal pressure against
closed glottis (seatbelt), crush bruise (clothesline
tackle)
rapid acceleration/ deceleration results in tracheal
injury
31. B) Suicidal
a)Hanging b)postural asphyxiation
◦ children with neck over object and body weight produces
compression
C)Accidental
i)carotid sleepers ii)bar arm control
a)choking
b)RTA : rapid deceleration hyperflexion,
hyperextension, and rotation vascular structures
are stretched over the cervical spine shearing
forces create intimal tears in the vessel wall
c)toxic gas inhalation
D)Judicial or justified hanging
32. Cause of death in hanging
Asphyxia
Venous congestion
Cerebral oedema
# vertebra
Significant cervical spine and spinal cord damage
can occur in hangings that involve a fall from a
distance greater than the body height.
Cause of death in strangulation
Vagal inhibition
Asphyxia
Cerebral anoxia & Venous congestion
33. Other consequences of Neck Trauma
Subcutaneous emphysema
Tension pneumothorax
Traumatic asphyxia
◦ Penetrating Trauma
Esophagus or Trachea
Vagus nerve disruption
◦ Tachycardia & GI disturbances
Thyroid & Parathyroid glands
◦ High vascular
34. More than 95% of penetrating neck wounds result
from guns and knives, with the remainder resulting
from motor vehicle accidents, household
injuries, industrial accidents, and sporting events
gun shot wound (GSW) sustain greater injury than
those with stab wounds because of a bullet's ability
to penetrate deeper and cause cavitation, thus
damaging structures lying outside the tract of the
missile.
Injury to the blood vessels can also result from
external compression or mural contusion.
Thrombosis is the most common complication of
blood vessel injury, occurring in 25-40% of
patients.
35. Blunt trauma to the neck typically results from
motor vehicle crashes but also occurs with sports-
related injuries (eg, clothesline tackle),
strangulation, blows from the fists or feet, and
excessive manipulation
In motor vehicle crashes, thrusting forward with
the head extended, forcing the anterior neck
against the steering column. Cerebral vessel and
laryngeal injuries secondary to shoulder strap
compression have occurred.
Direct forces can shear the vasculature producing
shearing damage and resultant thrombosis
36. Laryngotracheal Injuries in BNT
Although not prevalent, it is second to only
intracranial injury as the most common cause of
death among patients with head and neck trauma
and is a clinically important injury.
◦
◦ 60% of all external laryngotracheal traumas are due to
blunt neck trauma.
The final common pathway of laryngotracheal
injury is compressive force on the larynx leads to
injury. This is modified by the degree of laryngeal
calcification present;
37. Dissection of neck
Before exploring the neck the thorax and the
skuull should be opened and the viscera removed
After cutting the skin ,the ant cervical strap
muscles are cut and examined
Expose the thyroid cartilage & trachea
Following this ,the tongue ,hyoid bone & the larynx
are removed as unit.
Examine the hyoid bone after separating from
thyroid cartilage & soft tissues removed
See for periosteal haemorrhages & #
.Palpate the sup horn of thyroid cartilage .Examine
lamina of thyroid cartilage & cricoid cartilage for
injury.
Open thyroid cartilage posteriorly & examine
mucosa of larynx
38. Triticeous cartilage are little cartilaginous
nodules embedded in the thyroidhyoid
ligsment .These may be confused with a # of
superior horn of thyroid cartilage
Thank You