Majed Sharayha
Posts : 130
Reputation : 5
Join date : 2011-08-23
Age : 31
 |  Subject: Dr.Shreen, Sheet #3 - 1222012  Tue Feb 14, 2012 3:43 am | |
| Download Link ------------> Click here--------------------------------------------------------------------- Posterior Triangle
The Neck :
- Skin
- Superficial facia: has 3 contents
Platysma muscle ( the only muscle in superficial fascia)
Origin : pectoral fascia
Insertion : lower border of the mandible
Action : make wrinkles in the neck
In animals it is long , reaching thorax and abdomen
Nerve supply: cervical nerve (motor )
Coetaneous innervations
Anterior jugular vein
Sternomastoid muscle : or sternocleidomastoid
Origin: 2 heads
In front of Manubrium sterni ( sternal head)
Upper surface of Medial 1/3 of the clavicle( clavicular head )
Insertion: mastoid process
Nerve supply : Spinal accessory n. ( cranial nerve #11)
Action:
Two( on both side) : flex neck ant.
One ( unilateral ): lateral flexion,, rotation of the face toward the opposite side
** Sternomastoid muscle has a key position in the neck. It divide neck into 2 triangle:
Anterior
posterior
Posterior triangle
Boundaries:
Ant.: post. Border of sternomastoid muscle
Post.: ant. Border of Trapezius
Base: middle 1/3 of clavicle
Apex :overlapping between two Boundaries( sternomastoid & Trapezius)
-Deep fascia: (cervical fascia)
It divides into 4 parts:
investing deep cervical fascia surrounding the neck
prevertebral fascia surrounding prevertebral muscle
carotid sheath or carotid fascia surrounding carotid arteries
pretracheal fascia in front of Trachea
Roof:
Skin
superficial fascia ( with3 contents)
Investing layer of deep cervical fascia
Floor:
Muscles covered by prevertebral cervical fascia
Prevertebral muscles ( SLS)
Scalenus medius
Levator scapulae
Splenius capitis
* Scalenus anterior : under sternomastoid muscle( covered it)
* Scalenus posterior :deep to Scalenus medius
Note : Scalenus anterior & Scalenus posterior are not considered as part of posterior triangle
* Posterior triangle divided by omohyoid muscle into 2 subdivisions:
- smaller one: just above the clavicle supraclavicular
- larger one: related to occipital bone occipital
Omohyoid muscle:
origin: post. surface Of scapula
insertion: hyoid bone
This muscle junction between floor of the mouth to the beginning of the neck
Contents:
Divided into 2 divisions:
Nerves:
Brachial Plexus: (roots &trunks with its branches)
Roots Trunks
C5 Superior Branches: nerve to Subclavian,, Suprascapular n.
Branches of roots:
Long thoracic
Dorsal scapular
Phrenic nerve (C3,C4,C5)
C6
C7 Middle
C8 Inferior
T1
Roots & Trunks exit from plane lie between scalenus anterior & scalenus medius
Cutaneous innervations
Great auricular (C2,C3 )
branch from cervical plexus ( ventral Rami)
pursing deep fascia and become coetaneous in the midpoint of post. Border of sternomastoid
Course:
supply skin overlying the angle of the mandible (the only part in the face deos’nt take sensory innervation from Trigeminal nerve )
outer surface and medial surface of lower part of auricle
Lesser occipital ( C2)
branch from cervical plexus ( ventral Rami)
pursing deep fascia and become coetaneous in the midpoint of post. Border of sternomastoid
Pursing deep fascia and become coetaneous in the midpoint of post. Border of sternomastoid muscle
post. Border of sternomastoid
Innervations:
Upper part of medial surface of the auricle
Part of scalp just behind the auricle
Supraclavicular ( C3,C4)
branch from cervical plexus ( ventral Ramus)
Pursing deep fascia and become coetaneous in the midpoint of post. Border of sternomastoid
Course:
go to clavicle
divided into 3 divisions( median, intermediate ,lateral )
These branches supply skin overlying the pectoral region
Transverse cervical (C2,C3)
branch from cervical plexus ( ventral Rami)
pursing deep fascia and become coetaneous in the midpoint of post. Border of sternomastoid
Course:
crossing Sternomastoid transverse
Innervate ant. Aspect of the neck
If we gave anesthesia in the midpoint of post. Border of Sternomastoid this procedure Called Coetaneous innervations block of the neck
Spinal part of accessory cranial nerve
Course:
appears in the midpoint of sternomastoid
exist in the investing layer of deep fascia(roof) parallel on levator scapulae End at Trapezius muscle
if we cut the investing layer of deep fascia ,, this cause paralysis of spinal accessory that innervate trapezius & sternomastoid muscles shoulder drop and shoulder atrophy
Vascular content:
Subclavian Artery
Origin:
right side branch from brachiocephalic artery
Left side branch from Arch of Aorta
Course:
Until the outer border of first rib Axillary
divided by scalenus anterior muscle into:
First part of subclavian ( medial to muscle)
Second part of subclavian ( deep to muscle)
Third part of subclavian( lateral to muscle)
Third part :
content of post. Triangle
Enter the post. Triangle between scalenus ant. And scalenus (Neurovascular plane of the neck)
Subclavian vein:
Origin:
continuation of Axillary( outer border of first rib)
Course:
Unite with internal jugular v. Brachiocephalic v.(right&left) Superior vena cava
The only tributary enter subclavian v. external jugular vein
Two Arteries
Suprascapular artery: go to post. surface Of scapula
Transverse cervical: transverse in the neck
These two artery originate from first part of subclavian artery
First rib as we take previously has a tubercle called scalene tubercle which is the insertion of scalenus ant. Muscle
Ant. To it : groove for subclavian vein
Post. To it: groove for subclavian artery & lower trunk of brachial plexus
Done by:
Aya Mahfouz | |
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