Block 4: Neck 2
What is the laryngeal skeleton?
3 paired and 3 unpaired cartilages
What is Grave's disease?
HYPERthyroidism due to excessive production of thyroid hormone increased metabolism loss of weight and increased appetite heat intolerance TSH normal or reduced treated with drugs, radiotherapy, or removal of thyroid
What is Hashimoto's thyroiditis?
HYPOthyroidism that occurs due to insufficient production of thyroid hormone slow metabolism increased weight despite poor appetite cold intolerance TSH levels elevated treated with Levothyroxine
What are the branches of the thyrocervical trunk?
IATS inferior thyroid ascending cervical transverse cervical suprascapular
What are the branches of the costocervical trunk?
SD supreme intercostal artery deep cervical artery
What is the epiglottis?
a flap to close trachea during swallowing
What are the laryngeal muscles?
cricothyroid, vocalis thyroarytenoid, transverse arytenoid, lateral cricoarytenoid posterior cricoarytenoid
What muscles tighten the vocal cords?
cricothyroid: external laryngeal n. vocalis: recurrent laryngeal n. no effect on rima glottidis
What are the internal structures of the larynx?
epiglottis vestibular folds ventricles true folds
How are salivary glands stimulated?
hunger mastication seeing food smelling food tasting food thinking about food
What muscles adduct the vocal folds?
lateral cricoarytenoid, transverse arytenoid, thyroarytenoid recurrent laryngeal n. close rima glottidis
What is significant about the subclavian and clavicle junction?
pivotal point for n. entrapment and occlusion
What muscle abducts the vocal folds?
posterior cricoarytenoid recurrent laryngeal n. opens rima glottidis
What nerves are in the root of the neck?
recurrent laryngeal (CNX) vagus (CNX) phrenic (C3-5) brachial plexus sympathetic trunk
What is the Adam's apple?
the laryngeal prominence on the superior anteromedial aspect of the thyroid cartilage (level of C4)
What is in the thyroid region?
thyroid gland parathyroid glands neurovasculature
What are the superficial lymph nodes?
•5 groups of superficial lymph nodes form a ring around the head & are primarily responsible for the lymphatic drainage of the face & scalp •Submental nodes •Submandibular nodes •Parotid & pre-auricular nodes •Mastoid nodes •Occipital nodes •Superficial cervical lymph nodes lie along the EJV, on the surface of SCM •Superficial lymph nodes of the head drain to superficial cervical lymph nodes, which send vessels to the deep cervical lymph nodes
What is the function of the larynx?
•Acts as a passageway for inspired & expired air •Serves as a protective sphincter that prevents foreign bodies from entering the airway •Also the organ of phonation (larynx = "voicebox")
Thyroidectomy & Parathyroid glands
•All or part of the thyroid gland may be removed surgically •Performed for several reasons •Thyroid cancer •Multinodular goiter compressing nearby structures •Severe hyperthyroidism (Grave's)
What is a salivary duct calculi?
•Also known as salivary stones or sialolith •Calcified masses that can form within a salivary duct •80% are produced by the submandibular gland •Symptoms: unilateral pain & inflammation near the affected salivary gland •Exacerbated when salivary glands are stimulated (i.e. sight/smell/taste/thought of food, hunger, or chewing) •Most common in males between the ages of 30-60 Treatment Options •Small stones can be treated with NSAIDs, hydration, or sucking on citrus fruits to increase saliva production & force stone out •Large stones can be surgically removed by an ENT or oral/maxilofacial surgeon •Recurrent stones can require resection of the gland •
What is a PICC line?
•Basilic, cephalic, or brachial vv. are used •Ideal for patients receiving intravenous therapy for shorter-term treatments lasting one to six weeks •Can remain in situ for 7 days to 4 months •Primarily used for extended antibiotic therapy, total parenteral nutrition, or long chemotherapy regimens •Higher risk of infection (especially when swimming or bathing) •Sterile, non-surgical procedure •Usually inserted by physicians, physician assistants, radiology assistants, respiratory therapists, or nurse practitioners
What are the deep lymphatics of the neck?
•Deep cervical lymph nodes run along the IJV & drain deep structures of the head & neck •Also receive interstitial fluids from superficial cervical nodes •Deep cervical nodes form the right & left jugular trunks which drain into the right lymphatic duct & thoracic duct respectively •The right lymphatic duct & thoracic duct drain into the right & left venous angles respectively
What are sentinel nodes?
•Enlarged supraclavicular (inferior deep cervical) lymph nodes •Often hard, "fixed", & painless •Last location lymph passes before draining into the venous system •Via lymphatic trunks •More common on the left side •Due to thoracic duct •May indicate visceral malignancy in the thorax or abdomen
What is goiter?
•Enlargement of the thyroid gland that is non-neoplastic & non-inflammatory •Cause: usually insufficient dietary iodine •Usually asymptomatic •Symptoms can include swelling below the laryngeal prominence & cough •Result of the enlarged thyroid compressing the superior trachea, esophagus, & recurrent laryngeal nn. •The thyroid may enlarge anteriorly, posteriorly, laterally, & inferiorly •The sternothyroid m. prevents the thyroid's enlargement from projecting superiorly
What is a port?
•IJV is ideally used (can use subclavian v. if necessary) •Ideal for patients requiring occasional venous access for therapy over a prolonged period of time •Most ports remain in situ for 2-6 years •Primarily used to treat hematology & oncology patients •Some forms of chemotherapy require a port because the drug is too caustic to be delivered peripherally •5 million ports are placed in the US annually •Out-patient, surgical implantation procedure is requires moderate anesthesia •Usually inserted by an interventional radiologist or a surgeon along with a surgical team in an operating room
What is the sensory innervation of the larynx?
•Internal laryngeal n.: •branch of superior laryngeal n. •pierces the thyrohyoid membrane & provides sensation to structures above the true vocal folds •Recurrent laryngeal n.: •provides sensation to the true vocal folds & structures below
What are the vocal cords/folds?
•Located medial to the ventricles •The mucosa of the vocal folds cover the vocal ligament, conus elasticus & vocalis m. •Rima glottidis: opening between the R&L vocal folds •The glottis consists of both vocal ligaments & the rima glottidis •The vocal folds are ABducted/open when breathing •The vocal folds are ADducted & vibrating when speaking or singing •
What can feeling lymph nodes mean?
•Lymph nodes should normally be mobile, soft, discrete, and smooth (not lobulated) •Enlarged, painful, or tender nodes suggests inflammation and/or infection •Hard, lobulated, "fixed", & painless nodes suggest malignancy
What is the infraclavicular subclavian vein central line?
•Most common point of entry into the venous system for a central line placement, like a pulmonary artery catheter (PAC)/right heart catheter •To administer medications or venous nutritional fluids into the blood stream •To measure central venous pressure •Central line is placed through the subclavian v. inferolateral to the clavicle near the venous angle Procedure: •Place your non-dominant thumb on the middle part of the clavicle & your index finger on the jugular notch in the manubrium •Insert the needle inferior to the thumb (middle of the clavicle) and advance the needle medially toward the tip of the index finger (jugular notch) •Once the tip of the needle enters the venous angle, posterior to the sternoclavicular joint, use the needle as your guide to insert a soft, flexible catheter into the subclavian v. Caution: •If the needle is inserted too far inferiorly, it may puncture the pleura & the lung •Resulting in pneumothorax •If the needle is inserted too far posteriorly, it may puncture the subclavian artery
What are the types of saliva?
•Mucous - lubricates & binds masticated food together into a bolus to aid in swallowing •Serous - more watery, rich in proteins & enzymes like lysozyme & amylase •Mixed - both mucous & serous
What are the parts of the pharynx?
•Nasopharynx - base of skull to tip of soft palate (uvula) •Oropharynx - tip of soft palate (uvula) to epiglottis •Laryngopharynx - tip of epiglottis to inferior border of cricoid cartilage
What is a cricothyroidotomy?
•Performed when a patient's airway is obstructed by a foreign body •Only performed in emergency situations in which orotracheal intubation is not an option •Vertical incision made between the thyroid & cricoid cartilages •Establishes a patent airway •
What are the contents of the root of the neck?
•R & L subclavian aa. & branches •R & L common carotid aa. •External & anterior jugular vv. (EJVs, AJVs) •Venous angle •Junction of IJV, subclavian v., & thoracic duct •R & L subclavian vv. •R& L vagus n. (CN X) •R & L recurrent laryngeal nn. •R & L phrenic nn. •Roots of brachial plexus •Scalene mm. (ant., mid., post.) •Trachea •Esophagus
What is the motor innervation of the larynx?
•Recurrent laryngeal n.: •enters the larynx through the cricothyroid ligament •innervates 5 of the intrinsic laryngeal mm. •External laryngeal n.: •branch of superior laryngeal n. innervates cricothyroid m.
What is the IJV puncture?
•Similar to an infraclavicular subclavian v. central line •May be inserted into the IJV for diagnostic or therapeutic purposes •Right IJV is preferable because it is usually larger and straighter. Procedure: •Palpate the common carotid a. & insert the needle into the IJV just lateral to common carotid a. at a 30° angle •Aim towards the apex of the triangle between thesternal & clavicular heads of the SCM (the lesser supraclavicular fossa) •Then direct the needle inferolaterally toward the ipsilateral nipple •Once the needle has been placed, use it to guide a catheter into the IJV •
What is the thyrohyoid membrane?
•Spans the anterior surface of the larynx between the inferior border of hyoid & superior border of thyroid cartilage •Pierced by the superior laryngeal nn., aa., & vv.
What is the cricothyroid membrane?
•Spans the anterior surface of the larynx between the inferior border of thyroid cartilage & superior border of cricoid cartilage
What are the sublingual caruncles?
•Sublingual caruncles •Small prominences on either side of the lingual frenulum •Salivary excretions from the submandibular & sublingual glands enter the oral cavity through sublingual papillae at the sublingual caruncles
Where do your salivary excretions travel?
•Submandibular Glands •Secretions travel anteriorly along the deep side of the sublingual glands through the submandibular duct & drain into the sublingual caruncles just lateral to the lingual frenulum •Lingual n. (V3) crosses laterally under the submandibular duct •Sublingual Glands •Secretions travel anteriorly towards the lingual frenulum within the sublingual duct, deep to the oral mucosa, & drain into the sublingual caruncles
What are your salivary glands?
•Submandibular gland is superior to the post. digastric, along the inferior/posterior aspect of the mandible •A majority of the gland is superficial to mylohyoid m. •Supplied by branch of facial a. •produces 65% of saliva (mixed) •Sublingual gland lies on the deep side of the anteromedial aspect of the mandible •Supplied by branch of lingual a. •Parotid gland is superficial to the ramus of the mandible & masseter m. •Supplied by branch of superficial temporal a. & ECA
What is the viscera of the neck?
•Submandibular glands •Thyroid gland •Parathyroid glands (4) •Larynx & Trachea •Esophagus
What are the lymphatics of the head and neck?
•Superficial lymph nodes of the head •Superficial cervical lymph nodes •Deep cervical lymph nodes •Thoracic duct & right lymphatic duct
What are the arteries of the thyroid region?
•Superior & inferior thyroid aa. supply the thyroid & parathyroid glands •External carotid a --> superior thyroid a. --> superior laryngeal a. •Subclavian a --> inferior thyroid a. --> inferior laryngeal a.
What is the interscalene block?
•The most common unilateral spinal anesthesia technique for the upper extremity •Anesthetizes the roots of the brachial plexus •Used for surgical procedures on the shoulder, arm, forearm, or lateral 2/3 of clavicle & shoulder luxation •Anatomical landmarks for injecting local anesthetic: •Interscalene groove between anterior scalene & middle scalene •½ way between posterior border of SCM & anterior border of trapezius •At the level of the cricoid cartilage •Ultrasound-guided interscalene block techniques have improved consistency & reduced volume of local anesthetic required
What are the parathyroid glands?
•The parathyroid glands are 4 small glandular nodules on the posterior aspect of the thyroid (2 superior & 2 inferior) •The parathyroid glands produce & secrete parathyroid hormone which control the body's calcium levels
What is the relationship between larynx, esophagus, and trachea?
•The pharynx bifurcates into the esophagus posteriorly & the larynx anteriorly at the level of the chin •The larynx becomes the trachea below the cricoid cartilage •The esophagus is a muscular tube posterior to the larynx & trachea extends from the neck to the abdomen •
How is the thyroid innervated?
•The thyroid gland is innervated by the parasympathetic fibers from vagus n. (CN X) & sympathetic fibers from the superior, middle, & inferior cervical ganglia
What is the thyroid gland?
•The thyroid is deep to the sternothyroid muscles and anterolateral to the cricoid cartilage and proximal trachea (C5-T1) •The thyroid consists of 2 lobes connected by an isthmus at the midline •The thyroid gland produces & secretes hormones that control the body's metabolic rate •Also aids in heart & digestive function, muscle control, mood, & bone maintenance
Where does the thyroid venous plexus drain?
•The thyroid venous plexus drains into the superior, middle, & inferior thyroid vv. •Superior laryngeal v. to superior thyroid v. •Inferior laryngeal v. to superior & middle thyroid vv. •Drain into subclavian v.
What can thyroidectomies lead to?
•Total thyroidectomies can lead to hypoparathyroidism •Injecting carbon nanoparticles into thyroid tissue can help distinguish parathyroid glands •Thyroid gland will be dyed black, parathyroid glands remain unaffected •Parathyroid glands' blood supply from sup. & inf. thyroid aa. can also disrupted, leading to necrosis •Either can result in hypocalcemia
What is a tracheotomy?
•Transverse (horizontal) incision is made 2 fingerbreadths above sternal notch through tracheal rings •Tracheotomies are administered when airway access for prolonged mechanical ventilation is necessary •Not usually performed in an emergency •Open surgical tracheotomies are typically performed in a sterile OR
What is the pharynx and where does it terminate?
•Tubular structure shared by the respiratory & digestive systems •The laryngopharynx terminates at the level of C5-C6 to give rise to the trachea & esophagus
What are the branches of the subclavian a.?
•Vertebral a. •Internal thoracic a. •Thyrocervical trunk (4 branches-IATS) •Costocervical trunk (2 branches-SD) •Dorsal scapular a.*
What are the mucosal folds of the larynx?
•Vestibular folds = false vocal folds/cords •Not involved in phonation •False folds prevent foreign bodies from entering larynx The ventricles are 2 slit-like spaces between the false & true vocal folds •True vocal folds/cords •Formed by mucosa covering the vocal ligament, conus elasticus, & vocalis m. •Located just superior to the cricoid cartilage •Responsible for phonation