Anterior Triangle of the Neck PDF

ANTERIOR TRIANGLE OF THE NECK Class Year 2, Semester 1 Presenter Fiona Cronin Department of Anatomy [email protected] Date 29-10-2024 1 LEARNING OUTCOMES Demonstrate the anterior triangle, its boundaries, content, and...

ANTERIOR TRIANGLE OF THE NECK Class Year 2, Semester 1 Presenter Fiona Cronin Department of Anatomy [email protected] Date 29-10-2024 1 LEARNING OUTCOMES Demonstrate the anterior triangle, its boundaries, content, and subdivision Describe the location and course of major vessels and nerves Describe the anatomical features and development of the thyroid gland Identify the blood supply of the thyroid Describe the laryngeal nerves and the clinical significance of their course Describe the location of the parathyroid glands Identify the carotid sheath, arteries and its content Locate the carotid pulse Compare and contrast a laryngotomy and tracheotomy Describe the cervical sympathetic trunk and vagus nerve in neck ANTERIOR TRIANGLE VS. POSTERIOR TRIANGLE  Deep cervical fascia Prevertebral layer Recall Subcutaneous (superficial fascia) Investing layer Skin Outermost layer of the Platysma Deep Cervical Carotid sheath Fascia) Alar fascia Pretracheal layer Recall MUSCULAR TRIANGLES OF NECK HYOID BONE  Hyoid bone (C3) Superior thyroid notch (C4) Thyroid cartilage Cricoid cartilage (C6)  SUBDIVISIONS OF ANTERIOR TRIANGLE Anterior to SCM Can be subdivided (digastric & omohyoid) Submandibular Submental Carotid Muscular MUSCLES OF THE ANTERIOR TRIANGLE MUSCLES OF THE ANTERIOR TRIANGLE MUSCLES OF THE ANTERIOR TRIANGLE MUSCLES OF THE ANTERIOR TRIANGLE VESSELS OF THE ANTERIOR TRIANGLE  CAROTID SHEATH Column of fascia that surrounds the common carotid artery, the internal carotid artery, the internal jugular vein, and the vagus nerve CAROTID SYSTEM Right common carotid artery (CCA) originates from the brachiocephalic trunk posterior to the right sternoclavicular joint Left common carotid artery (CCA) begins in the thorax as a direct branch of the arch of aorta Near the superior edge of Thyroid cartilage @ C3/C4 each CCA divides into two terminal branches: External carotid artery (ECA) Internal carotid artery (ICA)  CAROTID PULSE Vital Sign Measurement Across the Lifespan - 2nd Canadian Edition by Jennifer L. Lapum; Margaret Verkuyl; Wendy Garcia; Oona St-Amant; and Andy Tan is licensed under a Creative Commons Attribution 4.0 International License, CAROTID SINUS Dilatation at the proximal part of the ICA (at the bifurcation) Contains receptors that monitor changes in the blood pressure Innervated by a branch of the glossopharyngeal nerve (IX CN)  BRANCHES OF EXTERNAL CAROTID ARTERY S – Superior thyroid artery A – Ascending pharyngeal artery L – Lingual artery F – Facial artery O – Occipital artery P – Posterior auricular artery M – Maxillary artery S – Superficial temporal artery  INTERNAL JUGULAR VEIN (IJV) Begins as a dilated continuation of the sigmoid sinus (dural venous sinus) Initial dilated part – superior bulb of the jugular vein Exists the skull - jugular foramen along with IX, X and XI cranial nerves and enters the carotid sheath IJV joins with the subclavian vein to form the brachiocephalic vein Tributaries – inferior petrosal sinus, facial, lingual, pharyngeal, occipital, superior thyroid and middle thyroid veins CENTRAL VENOUS CATHETERIZATION  NERVES Facial nerve Accessory nerve (VII CN) (XI CN)  NERVES Glossopharyngeal nerve Hypoglossal nerve (IX CN) (XII CN) NERVES Vagus nerve (X CN) THYROID AND PARATHYROID GLANDS THYROID GLAND BLOOD SUPPLY Source: Atlas of Clinical Gross Anatomy Moses, Kenneth Prakash, MD; Banks, John C., PhD... Published January 1, 2013. Pages 148-161. © 2013. CERVICAL SYMPATHETIC TRUNK Continuous with thoracic trunk Crosses the neck of the first rib Posterior to carotid sheath On prevertebral fascia Three Cervical ganglia: Superior – located at C1 & C2 vertebral level; branches pass to C1 to C4 spinal nerves Middle – located at the level of C6 vertebra; branches pass to C5 and C6 spinal nerves Inferior - named as Stellate ganglion, if merged with T1 ganglion; branches pass to C7 to T1 spinal nerves CERVICAL SYMPATHETIC TRUNK  Superficial cervical lymph nodes 1. Occipital LYMPH NODES 2. Mastoid (posterior auricular) 3. Pre-auricular and parotid 4. Submandibular 5. Submental Deep cervical lymph nodes 1. Jugulodigastric 2. Jugulo-omohyoid  Clinical application Compromised Airway Cricothyroidotomy (Laryngotomy) – a tube is inserted in the interval between the cricoid cartilage and the thyroid cartilage Tracheotomy – a tracheal tube is inserted between the 2nd and 4th tracheal rings Clinical application Tracheostomy tube TRACHEOTOMY REFERENCES PRACTICE QUESTIONS