Module 7b: The Neck Flashcards
Pharynx
-fibromuscular tube that extends from the base of the skull to the upper esophageal sphincter
What are the 3 constrictor muscles of the pharynx
-superior
-middle
-inferior
Upper esophageal sphincter
-formed by the lower part of inferior constrictor muscle of the pharynx
Upper esophageal sphincter function
-prevents reflux of food into airway and prevents air from entering the digestive tract
The pharynx
-situated posterior and communicates with, to the nasal cavities, oral cavity, and larynx
Divisions of the pharynx
-nasopharynx
-oropharynx
-laryngopharynx
The nasopharynx
-communicates with the nasal cavities anteriorly by choanae
-openings to eustachian tubes are located on lateral walls of nasopharynx
Pharyngeal tonsil
-collection of lymphatic tissue located on roof of nasopharynx
Soft palate
-can close the pharyngeal isthmus by elevation during swallowing
The oropharynx
-communicates anteriorly with oral cavity through the oropharyngeal isthmus
-each side of the oropharynx consists of 2 folds of mucous membranes supported by underlying muscles
Mucous membrane of the oropharynx
-palatoglossal arch
-palatopharyngeal arch
Palatine tonsil
-collection of lymphatic tissue between the folds
The laryngopharynx
-extends from oropharynx to esophagus
Piriform recesses
-2 recesses located on each side of the laryngeal inlet
-form channels that direct food from oral cavity to either side of the raised laryngeal inlet, towards the esophagus
Choking
-blockage of upper airway, usually above the vocal folds, can be defined as a partial or full. obstruction
Choking symptoms
-irregular breathing /coughing
-high pitched wheezing/no breathing
-lips may turn blue
-panic
-waving of area in distress
-loss of consciousness
Vestibular and vocal ligaments
-both ligaments are enclosed by their respective superficial folds
Vestibular fold
-false vocal cord
Vocal fold
-true vocal fold
Cricothyroid ligament
-originates from upper border of cricoid cartilage and extends superiorly where free upper margin forms vocal ligament
Arytenoid cartilage
-located at back of larynx, primary function is to close vocal folds when swallowing
-secondary function is to change tension of vocal folds for production of sound
Intrinsic muscles of the larynx
-thryoarytenoid
-cricothyroid
Thryoarytenoid
-originates from inferoposterior aspect of thyroid cartilage, and attaches to the anterolateral part of the arytenoid cartilage
Thryoarytenoid function
-acts to relax the vocal ligament, producing a softer voice
Thyroarytenoid innervation
-recurrent laryngeal nerve
Cricothyroid
-originates from anterolateral aspect of cricoid cartilage and attaches to inferior margin of thyroid cartilage
Cricothyroid function
-stretches and tenses the vocal ligaments for production of loud speech and different tones of voice
Cricothyroid innervation
-external laryngeal nerve
Laryngospasm
-rare but frightening experience and occurs when vocal folds
-suddenly seize up due to disruption in nervous input from laryngeal nerves, which can lead to airway obstruction
Laryngospasm symptoms
-can be provoked by various triggers such as asthma, allergies, exercise, irritants, stress, and/or anxiety, and most commonly GERD
Arterial supply of the thyroid gland
-supplied by superior thyroid artery, a branch of external carotid
-and inferior thyroid artery, a branch of thyrocervical trunk
Venous supply of the thyroid gland
-drained by the paired superior, middle, and inferior thyroid veins
-which form a venous plexus on the anterior surface of the thyroid gland descends anterior to trachea
Which vein may be source of bleeding during a tracheostomy
-inferior thyroid vein
Vagus nerve
-thyroid gland innervated by parasympathetic fibres arising from superior laryngeal and recurrent laryngeal nerve
-both branches of vagus
Sympathetic trunk
-thyroid gland innervated by sympathetic nerve fibres arising from superior, middle, and inferior cervical ganglia of sympathetic trunk
Goiter
-abnormal enlargement of thyroid gland at inferior pole, if it becomes significantly enlarged, it can compress structures in neck
Cricothyroid symptoms goiter
-altered tone of speech
Vagus nerve symptoms goiter
-difficulty breathing and swallowing
Trachea symptoms goiter
-tightness in throat
-unusual coughing
Phrenic nerve symptoms goiter
-difficulty breathing
Superficial muscles of the neck
-platysma
-sternocleidomastoid
Platysma
-runs from upper 2 ribs to lower margin of mandible, when it contracts, it tenses skin of neck and responsible for facial expression
Sternocleidomastoid
-originates inferiorly, on manubrium of sternum and medial end of clavicle to insert superiorly on mastoid process
-flex head and neck while individually tilting head towards either shoulder
Innervation of the sternocleidomastoid
-accessory nerve
Deep muscles of the neck
-scalenes
-levator scapulae
Scalenes
-3 muscles found in deep lateral neck, spanning between transverse processes of cervical vertebrae and ribs 1 and 2 `
Scalenes function
-flexion and rotation of the neck, accessory muscles of respiration, elevating ribs during forced inspiration
Levator scapulae
-long muscle situated at posterolateral neck, originates on transverse processes of cervical vertebrae 1-4 and inserts on scapula
Levator scapulae function
-to lift scapula and support the vertebral column
Sternocleidomastoid syndrome
-knot or very sensitive area in a muscle
Causes of sternocleidomastoid syndrome
-stress
-overuse of the muscle
-poor posture
-inactivity
Sternocleidomastoid symptoms
-pain in lateral neck, jaw, posterior head, and throat
-headaches
-neck stiffness
-tingling in face or neck
The hyoid bone
-u-shaped bone found superior to larynx and is attached by thyrohyoid membrane
-does not articulate with any other neck bones
Suprahyoid muscles
-muscles above hyoid bone
Infrahyoid muscles
-muscles below the hyoid bone
The suprahyoid muscles
-digastric
-stylohyoid
-mylohyoid
-geniohyoid
Digastric muscle
-has a posterior belly that attached to mastoid process, and an anterior belly that attaches to mandible
Intermediate tendon of digastric muscle
-runs between anterior and posterior bellies, it is held by a fascial sling to hyoid bone
Stylohyoid muscle
-originates from styloid process of temporal bone and inserts on hyoid bone
Mylohyoid muscle
-paired
-form the floor of oral cavity by joining together at midline raphe
-originate on mandible and insert on hyoid bone
Geniohyoid muscle
-originates from mandible and inserts on hyoid
Posterior belly of digastric muscle strain
-can occur from overuse or jaw misalignment
Posterior belly of digastric muscle strain symptoms
-pain in neck and under chin
-trigger points are located under angle of mandible
The infrahyoid muscles
-sternohyoid
-omohyoid
-thyrohyoid
Sternohyoid muscle
-originates from manubrium of sternum and inserts on hyoid bone
Omohyoid muscle
-has 2 bellies
-inferior belly originates on scapula and inserts on intermediate tendon
-superior belly originates at intermediate tendon and inserts on hyoid bone
Intermediate tendon of omohyoid
-attached to clavicle by fascial sling
Thyrohyoid muscle
-originates from thyroid cartilage and inserts on hyoid bone
Sternothyroid muscle
-originates from manubrium of sternum and inserts on thyroid cartilage
Omohyoid muscle syndrome
-mass in the neck located superior to clavicle that is only visible when patient swallows
Omohyoid muscle syndrome symptoms
-stiff and tender neck
Omohyoid muscle syndrome causes
-irritation or damage to muscle
-may result from excessive vomiting or neck trauma
Common carotid arteries
-internal
-external
Internal carotid artery
-brain and eyes
External carotid artery
-face and neck
Subclavian arteries
-paired
-originate in thorax
What do subclavian arteries supply
-thorax
-neck
-upper limbs
What do subclavian arteries arise from on left side of body
-aortic arch
What do subclavian arteries arise from on right side of body
-brachiocephalic trunk
Subclavian veins
-originate at outer border of first rib as continuations of axillary veins
What is another function of subclavian veins
-lymphatic drainage of head and neck
Atherosclerosis of internal carotid artery
-buildup of fats, cholesterol, and other substances in arterial walls
-may lead to narrowing and irregularity of artery’s lumen, preventing proper blood flow to brain
Atherosclerosis of internal carotid artery symptoms
-dizziness
-headaches
-confusion
-fainting
-death
Infrahyoid muscles lymphatic drainage
-superficial nodes
-vertical nodes
-jugular trunk
-thoracic and right lymphatic trunk
Superficial nodes
-includes submandibular nodes and submental nodes inferior to chin
Vertical nodes
-superficial cervical nodes
-deep cervical nodes
Superficial cervical nodes
-found on surface of SCM muscle and associated with external jugular vein
Deep cervical nodes
-found deep to SCM muscle and are related to the internal jugular vein
Jugular trunk
-from the deep cervical nodes
-lymphatic vessels drain into jugular trunks
Thoracic and right lymphatic trunk
-jugular trunks empty into thoracic duct on left side and right lymphatic duct on right
Recurrent strep throat
-bacterial infection of the pharynx, where lymph nodes become enlarged
Recurrent strep throat infection
-may suggest antibiotics are not working
-or there is an underlying immune condition
Recurrent strep throat symptoms
-pain with swallowing
-stiffness in neck
-headache
-fever
-sore throat
-red palatine tonsils
Cranial nerves of the neck
-glossopharyngeal
-hypoglossal
-vagus
Glossopharyngeal nerve innervation
-provides sensory innervation to tongue, pharynx, and middle ear
Hypoglossal nerve innervation
-supplies muscles of tongue
Vagus nerve innervation
-descends through neck to enter thorax, gives rise to nerves that form pharyngeal, parasympathetic cardiac, pulmonary, and esophageal plexuses
Branches of the vagus nerve
-right recurrent laryngeal
-left recurrent laryngeal
Right recurrent laryngeal nerve
-branch of right vagus nerve
-loops around right subclavian artery and ascends in groove between trachea and esophagus
Left recurrent laryngeal nerve
-branch of left vagus nerve
-loops beneath arch of aorta around ligamentum arteriosum and ascends in groove between esophagus and trachea
Unilateral vocal fold paralysis
-immobility of vocal folds due to damage or dysfunction of recurrent laryngeal nerve
-usually occurs as a result of blunt trauma
Unilateral vocal fold paralysis
-swallowing difficulty
-shortness of breath
-weak cough
-hoarseness of voice
The cervical plexus
-formed by ventral rami of cervical spinal nerves 1-4
The cervical plexus innervation
-motor innervation to most of muscles of neck
-sensory innervation to skin of neck and back of scalp
Infrahyoid muscle paralysis
-trauma to cervical spine can damage cervical plexus, resulting in muscular weakness from damaged nerves or paralysis
Infrahyoid muscle paralysis symptoms
-difficulties swallowing
-hoarse voice
-tightness in throat
Phrenic nerves
-right and left
-branches of cervical plexus
Phrenic nerves innervation
-motor and cutaneous innervation to diaphragm
Phrenic nerves path
-on way to thoracic inlet, each nerve crosses over anterior surface of scalene muscles and subclavian arteries
Path of right phrenic nerve
-passes anterior to right subclavian artery
-enters thorax through thoarcic inlet
-descends anterior to right lung root
-courses along pericardium
-pierces diaphragm at opening of inferior vena cava
Path of left phrenic nerve
-passes anterior to left subclavian artery
-enters thorax through thoracic inlet
-descends anterior to left lung root
-crosses aortic arch and left vagus nerve
-courses along pericardium
-pierces and innervates diaphragm
The sympathetic trunk
-spans the length of the vertebral column
-from base of skull to coccyx
-formed by sympathetic nerve fibres and ganglia
The cervical sympathetic ganglia
-superior cervical ganglion
-middle cervical ganglion
-inferior cervical ganglion
Superior cervical gangion
-largest
-positioned posterior to carotid arteries and anterior to C1-2 vertebrae
Middle cervical ganglion
-located anterior to inferior thyroid arteries and C6 vertebrae
-may be absent in some individuals
Inferior cervical ganglion
-situated anterior to C7 vertebrae and usually fused with 1st thoracic ganglion
Horners syndrome
-results from damage to sympathetic innervation of head
-namely the nerves leaving the cervical sympathetic ganglia
-may be caused by spinal cord lesions or certain types of tumours
Horners syndrome symptoms
-drooping of upper eyelid
-constriction of pupil
-absence of sweating on face and neck
