Clinical Anatomy of the Neck Part 1 PDF

Clinical Anatomy of the Neck Part 1 :Objectives At the end of this lect. Students should be able to : describe Triangles of the neck.1 ,The subcutaneous tissue nerves, veins of the neck.2 The main anatomical potential space in the neck.3.which lead to Spread Infections to the me...

Clinical Anatomy of the Neck Part 1 :Objectives At the end of this lect. Students should be able to : describe Triangles of the neck.1 ,The subcutaneous tissue nerves, veins of the neck.2 The main anatomical potential space in the neck.3.which lead to Spread Infections to the mediastinum Three major fascial compartments of the neck.4.Where the viscera of the neck are located. Major blood vessels of the neck.5.Lymphatic drainage system in Neck.6  The Neck Anteriorly lies between lower margin of mandible above & suprasternal notch & upper border of clavicle below. posteriorly Superior Nuchal line to intervertebral disc C7-T1. Visceral compartment anteriorly* Vertebral compartment posteriorly* Vascular compartments on each side laterally*  Landmarks of the neck Sternocleidomastoid Suprasternal fossa Greater supraclaviclar fossa Hyoid bone Thyroid cartilage Cricoid cartilage …Hyoid bone Is a U-shaped bone consisting of..… a median body, lesser horns (cornua) laterally, …………. paired , greater horns (cornua) posteriorly……… paired ▪ Body.1 : Provides attachments for ,Geniohyoid muscle ▪ mylohyoid, muscle ▪ ,Omohyoid muscle ▪.sternohyoid muscle ▪ Greater horn.2 : Provides attachments for ,middle constrictor ▪ ,hyoglossus ▪ ,digastric (anterior and posterior) bellies ▪ ,stylohyoid ▪.thyrohyoid muscle ▪ Lesser horn.3 : Provides attachment for ,stylohyoid ligament which runs from styloid process to lesser horn  ❖ Palstysma: ? ❖ tenses skin, ❖ producing vertical skin ridges ❖ releasing pressure on superficial veins. ❖ use in shaving ❖ ❖ in a grimace. ❖ depress the mandible and draw corners of mouth inferiorly ❖ Acting its inferior attachment ❖ convey tension or stress Skin of Neck lines of cleavage of skin are constant.run …..horizontally …..around neck ▪ ,an incision :along a cleavage line will heal as a narrow scar  :Deep Cervical Fascia ❖ support : ❖ viscera (thyroid gland), ❖ muscles, ❖ vessels, & ❖ deep lymph nodes. ❖ condenses around : ……… to form carotid sheath ❖ form natural cleavage planes ❖ tissues may be separated during surgery, ❖ limit the spread of abscesses (collections of pus) ❖ afford slipperiness ❖ allows structures in neck to move and pass over one another without difficulty, ❖ swallowing and turning the head and neck. ❖ Carotid Sheath ❖ is a tubular fascial investment ❖ extends from cranial base to root of neck. ❖ blends ❖ anteriorly with investing and pretracheal layers ❖ posteriorly with prevertebral layer ❖ contains : ❖ common and internal carotid arteries, ❖ internal jugular vein, ❖ vagus nerve (CN X), ❖ deep cervical lymph nodes, ❖ carotid sinus. ❖ sympathetic nerve fibers (carotid periarterial plexuses). ❖ carotid sheath and pretracheal fascia communicate freely with: ❖ mediastinum of thorax inferiorly & ❖ cranial cavity superiorly. ❖ represent potential pathways for spread of infection and extravasated blood.  : A. The posterior triangle ❖ subdivided by the inferior belly of the Omohyoid muscle into an occipital supraclavicular triangles. ❖ The roof: ❖ the skin and deep cervical fascia. ❖ The floor: ❖ the prevertebral fascia ❖ The content: ❖ Occipital lymph nodes, accessory nerve, greater auricular nerve and the cervical plexus.  B. Anterior triangle Roof:……formed by: platysma investing layer of deep cervical fascia. Is further divided by : ▪ omohyoid superior belly ▪ digastric anterior and posterior bellies into : digastric (submandibular), Submental (suprahyoid), Carotid triangle muscular (inferior carotid) triangles.  Nerves in the posterior triangle Cervical plexus-1 Brachial plexus-2 spinal root of -3 accessory nerve (11th cranial nerve ) four muscular branches -1 Roots , trunks and their branches dorsal scapular nerve –c5(nerve to -1 It is the most important four cutaneous branches -2 rhomboids ) nerve to subclavius – c5 &c6 -2 structure in the occipital nerve to serratus anterior –c5,6 &7 -3 triangle Suprascapular nerve –c5&6  A. (CN XI) Accessory nerve : Is formed by union of.cranial & spinal roots : cranial roots arise from medulla oblongata below roots of vagus. : spinal roots ▪ arise from lateral aspect of cervical segment of spinal cord ▪ between C1 – C5 ▪ unites to form a trunk ▪ ascends between dorsal & ventral roots of spinal nerves in vertebral canal ▪ passes through foramen magnum. ,Has both spinal and cranial portions.traverse jugular foramen, they interchange fibers  cranial portion ▪contains motor fibers.. join vagus nerve ▪innervate soft palate, pharyngeal constrictors, & larynx. spinal portion ▪innervates sternocleidomastoid & trapezius muscles. ▪Lies on levator scapulae in posterior cervical triangle ▪passes deep to trapezius.  B. Cervical plexus.Is formed by ventral primary rami of C1 to C4 Cutaneous branches.1 a- Lesser occipital nerve (C2) Ascends along posterior border of sternocleidomastoid to scalp.behind auricle b- Great auricular nerve (C2-C3) Ascends on sternocleidomastoid.innervate skin behind auricle & on parotid gland C- Transverse cervical nerve (C2-C3) Turns around posterior border of sternocleidomastoid.innervates skin of anterior cervical triangle D-Supraclavicular nerve (C3-C4) Emerges as a common trunk from under sternocleidomastoid.divides into anterior, middle, & lateral branches to skin over clavicle &shoulder Motor branches.2 Ansa cervicalis………………Is a nerve loop formed by union of : ▪ superior root (C1) descendens hypoglossi ▪ inferior root (C2--C3; descendens cervicalis. Lies superficial to carotid sheath in anterior cervical triangle. Innervates infrahyoid (strap) muscles: ▪omohyoid, ▪sternohyoid, ▪sternothyroid muscles, with exception of thyrohyoid muscle, innervated by C1 via hypoglossal N. Phrenic nerve (C3-C5).3 Arises from chiefly from 4th cervical nerve; contains : ▪ motor, ▪ sensory, ▪ sympathetic nerve fibers; Provides: ▪ motor supply to diaphragm ▪ sensation to its central part. supply sensory fibers to these structures. longus capitis and cervicis or colli, sternocleidomastoid, trapezius, levator scapulae, scalene muscles. Accessory phrenic nerve (C5) ▪ arises as a contribution of : ▪ C5 to phrenic nerve or ▪ a branch of nerve to subclavius (C5), ▪ descends lateral to phrenic nerve, ▪ enters thorax by passing posterior to subclavian vein, ▪ joins phrenic nerve below first rib to supply diaphragm. Main Arteries and Veins of Neck Superficial Veins External Jugular Vein The external jugular vein begins just behind the angle of the mandible by the union of the posterior auricular vein with the posterior division of the retromandibular vein Visibility of the External Jugular Vein The external jugular vein is less obvious in children and women because their subcutaneous tissue tends to be thicker than the tissue of men The External Jugular Vein as a Venous Manometer The external jugular vein serves as a useful venous manometer External Jugular Vein Catheterization The external jugular vein can be used for catheterization, but the.presence of valves or tortuosity may make the passage of the catheter difficult  Carotid Sinus ❖ At its point of division, the common carotid artery shows a localized dilatation, called carotid sinus ❖ It serves as a reflex pressoreceptor mechanism ❖ A rise in blood pressure causes a slowing of the heart rate and vasodilatation of the arterioles  Carotid Body ❖ It is a small structure lies posterior to the point of bifurcation of the common carotid artery ❖ It is innervated by glossopharyngeal nerve ❖ It serves as a chemoreceptor ❖ Sensitive to excess carbon dioxide and reduced oxygen tension in the blood ❖ Stimulus reflexly produces a rise in blood pressure and heart rate and increase in respiratory movements : Lymph pathway Deep cervical lymph nodes ---------efferent lymph vessels---------jugular lymph trunk----- : Left side----Thoracic duct -------at the junction of the subclavian and internal jugular veins Right side-------Right lymphatic duct ------ venous system at the junction between the subclavian and internal jugular veins Clinical application Carotid Sinus Massage: initial treatment of hemodynamically stable paroxysmal supraventricular tachycardia Cervical metastasis --- removal en block of the internal jugular vein , the fascia, lymph nodes and submandibular salivary gland (removal of all the lymph tissues on the affected side of the neck) Radical or Modified Radical Neck Dissection.  LYMPH What is lymph ? Tissue fluid (interstitial fluid) that enters the lymphatic vessels  LYMPHATIC SYSTEM Essentially a drainage What is lymph ? system accessory to venous system *Tissue fluid (interstitial fluid) that enters the lymphatic vessels larger particles that escape into tissue fluid can only be removed via lymphatic system  LYMPHATIC DUCTS 24- Right lymphatic duct 56 Formed by union of right jugular, subclavian, and bronchomediastinal trunks Ends by entering the right venous angle  LYMPHATIC DUCTS ❖Thoracic duct ❖ Begins in front of L1 as a dilated sac, the cisterna chyli, ❖ formed by left and right lumbar trunks and intestinal trunk ❖ Enter thoracic cavity & ascends ❖ Travels upward, veering to the left at the level of T5  DRAINAGE PATTERN RIGHT LYMPHATIC DUCT -Receives lymph from right half of head, neck, thorax and right upper limb, right lung, right side of heart, right surface of liver THORACIC DUCT - Drains lymph from lower limbs, pelvic cavity, abdominal cavity, left side of thorax, and left side of the head, neck and left Deep Cervical Lymph Nodes Clinical Anatomy of the Neck Part 2 Thyroid- Salivary- Lymph nodes-  THYROID DISEASE—BENIGN thyroid goitre, hypothyroidism hyperthyroidism  Thyroid gland: Anatomy right and left lobes connected by a*.narrow isthmus It is surrounded by a sheath derived from* the pretracheal layer of deep fascia. The sheath attaches the gland larynx and.trachea Each lobe is pear shaped, its base lies* below at the level of the fourth or fifth tracheal ring , its apex directed upward as far as the oblique line on the lamina of the.thyroid cartilage The isthmus extends across the midline in. front of the 2,3,and 4th tracheal ring A pyramidal lobe is often present , and it project upward from isthmus usually to.the left of the midline  Thyroid gland: Anatomy Blood supply. superior thyroid artery branch of external carotid artery -1. inferior thyroid artery branch of thyrocervical trunk -2 thyroid ima artery if present branch of brachiocephalic artery or arch -3.of aorta ,it ascend in front of the trachea to the isthmus Venous drainge to superior and middle thyroid veins which drains into internal jugular -1 vein and the inferior thyroid veins which drain into the left brachiocephalic vein Lymph drainage mainly to deep cervical lymph nodes -1 a few to the paratracheal nodes -2 Nerve supply.Superior , middle and inferior cervical sympathetic ganglia  parathroid glands.Parathyroid glands are ovoid bodies measuring about 6 mm long in their great diameter- they are 4 in number and are closely related to the posterior border of the thyroid gland, lying --.within its fascial capsule the two superior parathyroid glands are the more constant in position and lie at the level of the -.middle of the posterior border of the thyroid gland The two inferior glands usually lie close to the inferior poles of the thyroid glands. They may lie - within the fascial sheath , embedded in the thyroid substance , or outside the fascial sheath. Sometimes , they are found some distance caudal to the thyroid gland even in the superior mediastinum in the thorax Blood supply- From superior and inferior thyroid artery- Venous drainage to the superior , middle and inferior thyroid veins- Lymph drainage- Deep cervical and paratracheal lymph nodes- Nerve supply-.Superior or middle cervical sympathetic ganglia-  Classification of goitre Simple (non toxic) Diffuse, nodular, multinodular, and recurrent.nodular.Toxic Diffuse, nodular, multinodular, and recurrent nodular.Inflammatory Hashimoto’s, De Quervain’s, Reidel’s thyroiditis.Neoplastic Benign and malignant Rare goitres TB, amyloid, syphilis, HIV and lithium Thyroid Physiology Thyroid hormone synthesis, metabolism and action ❖ Iodine enters thyroid gland and is used for T3 and T4 production ❖ Hormones are released from the thyroid and vast majority are protein bound (TBG) and deposited in peripheral cells ❖ T4 has 4 iodine atoms, removal of one produces T3 ❖ Total= Bound to TBG ❖ Free= Unbound  T3 & T4 ❖ Facilitate normal growth and development ❖ Increase metabolism ❖ Increase catecholamine effects TSH ❖ Most useful marker of thyroid hormone function ❖ Released in a pulsatile diurnal rhythm- highest at night  Hypothyroidism Insufficient thyroid hormone Primary: thyroid gland failure.1 Secondary: pituitary gland failure.2 Tertiary: hypothalamus failure.3  Hypothyroidism Causes ❖ Primary hypothyroidism ❖ Iodine deficiency- most common cause worldwide ❖ Congenital ❖ Autoimmune mediated ❖ Hashimoto’s thyroiditis- B lymphocytes invade thyroid ❖ Iatrogenic- post-thyroidectomy or radio-iodine treatment ❖ Drug-induced – Anti-thyroid, lithium, amiodarone ❖ Severe infection ❖ Trauma to thyroid/pituitary/hypothalamus ❖ Pituitary tumour  Hyperthyroidism Causes ❖ Hyperthyroidism (thyrotoxicosis) is excess thyroid hormone ❖ 1.Autoimmune ❖ Graves Disease (76%) ❖ F>M, age 20-40 ❖ IgG auto antibodies bind TSH receptors T3 & T4 ❖ Leads to gland hyper function ❖ 2. Toxic adenoma and toxic multinodular goitre ❖ 3. Viral Thyroiditis (de Quervain’s) ❖ Fever and ESR- self limiting ❖ 4.Exogenous Iodine ❖ 5.Neonatal thyrotoxicosis ❖ 6.Drugs- Amiodarone ❖ 7.TSH secreting pituitary adenoma (rare)  Investigating Thyroid Disease ❖ TSH- first thing you assess ❖ Normal range 0.5-5 μU/ml ❖ Supressed= Hyperthyroid ❖ Elevated= Hypothyroid ❖ If TSH abnormal request Free T4 ❖ Elevated= Hyperthyroid ❖ Suppressed= Hypothyroid  Investigations – TFTs - + - TSH + TSH TSH TSH - + - + T3, T4 T3, T4 T3, T4 T3, T4 Hypothyroidism Hyperthyroidism Hypopituitarism TSH secreting tumour ↑TSH; ↓T4,T3 ↓TSH; ↑T4,T3 ↓TSH; ↓T4,T3 ↑TSH; ↑T4,T3  Investigations – Other tests ❖ Bloods ❖ Thyroid auto-antibodies ❖ Anti thyroid peroxidase antibodies ❖ TSH receptor antibodies – Graves’ disease ❖ USS Thyroid- can detect nodules >3mm ❖ FNAC ❖ Isotope scan ❖ CXR- retrosternal expansion or tracheal compression  Investigating Thyroid cancers ❖ Serum calcitonin & CEA (CarcinoEmbryonic Antigen ) in Medullary cancer ❖ Radioactive iodine scan ❖ Ultrasound ❖ FNA ❖ CT scan- detects metastases ❖ MRI and PET scans- distant metastases  Treatment ❖ Medical and /or surgical ❖ The indications for surgery are: ❖ Suspected malignancy. ❖ Cosmetic reasons. ❖ Tracheal or oesophageal compression. ❖ Thyrotoxicosis.  Types of surgery ❖ The following operations can be performed on the thyroid gland: ❖ Lumpectomy. ❖ Hemithyroidectomy (total lobectomy). ❖ Subtotal thyroidectomy. ❖ Near-total or total thyroidectomy.  Management ❖ There are a number of treatment modalities for thyroid malignancy ❖ Surgery. ❖ Radio-active iodine. ❖ External beam radiotherapy. ❖ Hormonal manipulation. ❖ Chemotherapy ❖ *** e.g. :Treatment: Total thyroidectomy & wide LN clearance ❖ RAI ablation for papillary & follicular  Salivary glands Salivary glands: are composed of 4 major glands, in addition to minor glands. Major: Minor: 2 parotid glands. Multiple minor 2 submandibular glands glands 2 Sublingual glands.  ANATOM Y GLAND 1. PAROTID ❖ Important structure that run through the parotid gland: ❖ Branch of facial nerve. ❖ Terminal branch of external carotid artery that divided into maxillary & superficial temporal artery. ❖ The retromandibular vein ( post. Facial ). ❖ Intraparotid lymph node.  1.THE PAROTID DUCT: Stensen’s duct is 5 cm long. open opposite the second upper molar tooth  2. SUBMANDIBULAR GLAND It’s paired of gland that lie below the mandible on either side. Has 2 lobes, superficial & deep. Warthon’s duct, drained submandibular gland that opens into anterior floor of mouth. Anatomical relationship: Lingual nerve. Hypoglossal nerve. Anterior facial vein. Facial artery. Marginal mandibular branch of facial nerve.  3. SUBLINGUAL GLAND Lie on the superior surface of the mylohyoid muscle and are separated from the oral cavity by a thin layer of mucosa. The ducts of the sublingual glands drained by 8-20 excretory ducts called the ducts of Rivinus.  4. MINOR SALIVARY GLAND ❖ About 450 lie under the mucosa ❖ They are distirbuted in the mucosa of the lips, cheeks, palate, floor of mouth & retromolar area ❖ Also appear in oropharyanx, larynx & trachea  SALIVA - Functions Epithelial lubrication PROTECTION For tooth: Rinsing ALIMENTARY Food approval: taste, texture Mastication Digestion MATERIALS Swallowing Water OTHER Vocalization Mucins (glycoproteins) Antibodies IgAs Lysozyme Amylase  Salivary Gland Diseases Functional disorders.1 Sialorrhea (Increase in saliva flow) Xerostomia (Decrease in saliva flow) Obstructive disorders.2 stone (Sialolith) Mucocel (ranula) Infectious disorders.3 Acute Sialadenitis – Infectious( viral / Mumps, or Bacteria/ staphylococcal Chronic Sialadenitis: tuberculosis Neoplastic disorders.4 Benign. Pleomorphic adenoma, Warthin’s tumour. Malignant. Adenoid cystic carcinoma, adenocarcinoma  :Neoplastic disorders of salivary glands ❖ * 80% of all salivary tumours are in the parotid, 80% of parotid tumours are benign and 80% of the benign tumours that arise in the parotid are pleomorphic adenoma. ❖ One in three tumours arising in the submandibular gland are malignant ❖ *one in two tumours that arise in the minor salivary glands are malignant DISORDERS OF MINOR & SUBLINGUAL SALIVARY GLAND CYST It’s either: Extravasation cyst result from trauma to overlying mucosa. Mucous retention cyst in the floor of the mouth due to obstruction. RANULA extravasation cyst that arises from sublingual gland. PLUNGING RANULA It is rare form of mucus retention cyst arise from both sublingual & submandibular. The mucus collects around the gland &penetrates the mylohyoid diaphragm to enter the neck. Pt. presents with Dumbbell shaped swelling , soft, fluctuant & painless  Approach of the neck mass Evaluation and management of a neck mass in the adult patient. (CT = computed. tomographic; PPD = purified protein derivative) QQQ