1. Pharyngeal spaces
   1. Retropharyngeal space
   2. Lateral Pharyngeal space
   3. Situated
      1. Dead space behind pharynx
      2. Side of pharynx
   4. Function
      1. Acts as bursa for expansion of pharynx during deglutition
      2. N/a
   5. Boundaries
      1. Ant : Buccopharyngeal fascia posterior : Prevertebral fascia sides. : Carotid sheath
      2. Medial. :Pharynx posterolateral : Parotid gland Anterolateral : Medial pterygoid Posterior. : Carotid sheath
   6. Superior
      1. Base of skull
      2. N/a
   7. Inferior
      1. Continuous with superior mediastinum & open
      2. N/a
   8. Contents
      1. Retropharyngeal LN, pharyngeal plexus of vessels & nerves, loose areolar tissue
      2. Branches of maxillary artery & fibrofatty tissue
   9. Clinical
      1. Pus collection due to LN
      2. Pus collection or ludwig’s angina
   10. Anatomy
       1. Abscess which lies in paramedian position should be differentiated from cold abscess of spine of cervical vertebrae which is seen in median plane
       2. .n/a
2. Deep Cervical Fascia ( Fascia colli)
   1. Deep fascia is condensed to form following layers
      1. Layers of DEEP CERVICAL FASCIA
         1. 1. Investing layer
            1. a. Lies deep to platysma b. Surrounds neck like collar c. Forms roof of post. Triangles of neck d. Splits to enclose *Spaces: suprasternal & supraclavicular *Muscles: Trapezius & Sternocleidomastoid *Salivary glands: Parotid & Submandibular
            2. a. Parotid swellings are very painful due to unyielding nature of parotid fascia b. Division of External jugular vein in supraclavicular space may cause air embolism & consequent death, because fascia is attached firmly to vein & prevents retraction
         2. 2. Pretracheal fascia
            1. a. Encloses & suspends Thyroid gland & forms its false capsule, forms suspensory ligament of Berry.
            2. Thyroid gland & all swellings of thyroid move with deglutition because thyroid is attached to cartilage of larynx by ligament of Berry
         3. 3. Prevertebral fascia
            1. a. In front of prevertebral muscles & forms floor of posterior triangle of neck b. Covers pherenic N c. Also forms axillary sheath d. Provides fixed base for movements of pharynx, oesophagus & carotid sheaths during swallowing
            2. a .Neck infections behind pretracheal fascia is due to tuberculosis b. Neck infection infront of pretracheal fascia is due to suppuration in retropharyngeal LN
         4. 4. Carotid sheath
            1. a. Formed on ant. Aspect by pretracheal fascia & on posterior aspect by prevertebral fascia* b. Common carotid artery, Internal carotid arteries , Internal jugular vein & Vagus nerve.* at upper part of sheath IX, XI, XII nerves are present* c. Ansa cervicalis is embedded in ant wall* d. Cervical sympathetic chain lies behind the sheath, plastered to prevertebral fascia
         5. 5. Buccopharyngeal Fascia
            1. a. Covers all constrictor muscles externally & extends onto superficial aspect of buccinator b. Space behind fascia is called Retropharyngeal space, alar fascia divides it into 2 parts.
            2. Posterior space between alar & prevertebral fascia is dangerous space in the neck
         6. 6. Pharyngobasilar Fascia
            1. Upper border of superior constrictor ms & the base of skull. Lies deep to pharyngeal muscles
3. Layers in neck
   1. 1.Skin skin of neck is supplied by second, third & fourth cervical nerves**
   2. 2. Superficial fascia contains areolar tissue with platysma* Deep to platysma are cutaneous nerves, superficial veins, lymph nodes and small arteries.
   3. 3. Deep Fascia
   4. 4. Muscles like sternocleidomastoid which divides the triangles of neck in ant & post triangles
4. Boundaries
   1. 1. Anteriorly by anterior median line 2. Posteriorly by ant. Border of trapezius 3. superiorly, by base of mandible, line joining angle of mandible to mastoid process, & superior nuchal line 4. Inferiorly by clavicle
5. Posterior triangles of neck
   1. Boundaries a. Anterior : posterior border of sternocleidomastoid b. Posterior: Anterior border of trapezius c. Base: Middle 1/3 rd of clavicleapex : superior nucal line where SCM & trapezius meet
   2. Roof formed by investing layer of deep cervical fascia Superficial fasia contains platysma, external jugular vein, lesser occipital nerve ,great auricular & supraclavicular nerve
   3. Floor formed by prevertebral layer of deep cervical fascia, covering following muscles: 1. Scalenius capitis 2. Levator scapulae 3. Scalenus medius 4. Semispinalis capitis
   4. Subdivision Divided by inferior belly of omohyoid into 1. Large upper part : occipital part 2. Small lower part: supraclavicular/ subclavian part
      1. Contents of posterior triangle
         1. Nerves
            1. 1. Spinal accessory nerve 2. Cutaneous branch of cervical plexus a. Lesser occipital ( C2) b. Great auricular ( C2 C3) c. Anterior cutaneous nerve of neck ( C2 C3) d. Supraclavicular nerves ( C3 C4) 3. Muscular branches a. 2 Branch to levator scapulae ( C3 C4) b. 2 branches to trapezius ( C3 C4) c. Nerve to rhomboids ( C5)
            2. 1. Roots & trunks of brachial plexus 2. Nerve to serratus anterior ( long thoracic C5- C7 ) 3. Nerve to subclavius ( C5 C6) 4. Suprascapular nerve ( C5 C6)
         2. Vessels
            1. 1. Transverse cervical artery & vein 2. Occipital artery
            2. 1. 3 rd part of subclavian artery & vein 2. Suprascapular artery & vein 3. Transverse cervical artery & termination of corresponding vein 4. Lower part of external jugular vein
         3. Lymph nodes
            1. Along post border of SCM more in lower part - supraclavicular nodes few at upper angle- occipital nodes
            2. Few members of supraclavicular chain
6. Sternocleido mastoid muscle
   1. Large muscle of neck & supplied by spinal root of accessory nerve. Divide the triangles of nech into ant. & post. Triangles
   2. Origin: 1. Sternal head is tendinous & arises from superolateral part of front of manubrium sterni 2. Clavicular head is musculotendinous & arises from medial one-third of superior surface of clavicle
   3. Insertion: 1. By thick tendon to Lateral surface of mastoid process 2. By thin aponeurosis into lateral half of superior nuchal line of occipital bone
   4. Nerve supply 1. Spinal accessory nerve provides motor supply, it passes through the muscle 2. Branches from ventral rami of C2 & C3 are proprioceptive
   5. Blood supply 1. Arterial supply : one branch each from superior thyroid artery & suprascapular artery & 2 branches from occipital artery 2. Veins follow the arteries
   6. Actions : 1) when single muscle contracts * turns the face to opposite side * can also tilt the head towards the shoulder 2) when both muscles contract together * They draw the head forward as in eating & in lifting the head from pillow * with longus colli, they flex the neck against resistance. The reverse action helps in forced inspiration
7. a. Suprasternal space : aka space of burns Contains : rt & lt sternal heads of sternocleidomastoid, jugular venous arch, interclavicular ligament b. Supraclavicular space : traversed by External jugular vein Supraclavicular nerves & cutaneous vessels