Module 7B- neck Flashcards
pharynx
fibromuscular tube that extends from the base of the skull to the upper esophageal sphincter (U E S ).
how are the fibromuscular walls of the pharynx formed
by three pairs of constrictor
muscles
constrictor muscles
superior, middle, and inferior pharyngeal constrictors.
how is the upper esophageal
sphincter (U E S ) formed
by the lower part of the inferior constrictor muscle of the pharynx
upper esophageal
sphincter (U E S ) function
prevents reflux of food into the airway and prevents air from entering the digestive tract
systems of the pharynx
- digestive and respiratory systems are part of the pharynx
division of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
where is the pharynx situated?
posterior to and communicate with the nasal cavities, oral cavity, and larynx
nasopharynx communicates with
the nasal cavities anteriorly by the choanae (posterior nasal
apertures).
what are in the nasopharnyx
opening to the eustachian tubes
where are the opening in the Eustachian tubes located in the nasopharynx
on the lateral walls of the nasopharynx
what is the roof of the nasopharynx?
a collection of lymphatic tissue called the pharyngeal tonsil
what does the nasopharynx communicate inferiorly
with the oropharynx by the pharyngeal isthmus
pharyngeal isthmus closing
by elevation of the soft palate during swallowing
what does the oropharynx communicate with anteriorly
with the oral cavity through the oropharyngeal isthmus
each of the oropharynx
- consists of 2 folds of mucous membranes supported by underlying muscles
muscles of the oropharynx
palatoglossal arch posterior palatopharyngeal arch
what is between the mucous membrane folds in the oropharynx
collection of lymphatic tissue, the palatine tonsils
medial surface of the palatine tonsils
projects into the oropharynx
lateral side of the palatine tonsils
lies against the superior constrictor muscle
laryngopharynx
extends from the oropharynx to the esophagus.
laryngeal inlet
opens into the anterior wall of the laryngopharynx.
where does the cavity of the paryngopharynx extend + what does it form
anteriorly, one each side of the laryngeal inlet forming 2 recesses called the piriform recesses (fossae)
piriform recesses (fossae)
form channels that direct food
from the oral cavity to either side of the raised laryngeal inlet, toward the esophagus
choking
- blockage of the upper airway by an object, usually above the vocal folds. Choking
can be defined as a partial obstruction or full obstruction. - You can follow the pathway of the object from the oropharynx to the laryngopharynx.
Symptoms Choking
irregular breathing/coughing from a partially blocked airway or high-pitched wheezing/no breathing from a complete obstruction. The lips
may turn blue from the lack of oxygen reaching the head. Individuals will be panicked and wave their arms in distress and may eventually lose consciousness
what is the larynx formed by?
by a cartilaginous skeleton and is held together by ligaments
cartilage and ligaments of the larynx
Vestibular and Vocal Ligaments
Cricothyroid Ligament
Arytenoid Cartilage
Vestibular and Vocal Ligaments
Both ligaments are enclosed by their respective superficial folds - the vestibular fold
and vocal fold
the vestibular fold
(false vocal fold)
vocal fold
(true vocal fold).
Cricothyroid Ligament
Originates from the upper border of the cricoid cartilage and extends superiorly where its free upper
margin forms the vocal ligament (‘true vocal cord’).
Arytenoid Cartilage
Located at the back of the larynx,
Arytenoid Cartilage function
- primary function is to close the vocal folds when swallowing.
- secondary function is to change the tension of the vocal cords for the production of sound
what are vocal cords responsible for?
the production of vocal sounds
how are movements of vocal cords controlled
by the instrinsic muscles of the larynx
during respiration the vocal cords
abducts (open)
during swallowing vocal cords
adduct (close)
during phonation the vocal cords partially
adduct and alter tension of them
what are the functions of the intrinsic laryngeal muscles
control the shape of the rima glottidis, and the length and tension of
the vocal ligaments during breathing, swallowing, and phonation.
what are the 2 intrinsic muscles of the larynx.
Thyroarytenoid
Cricothyroid
Thyroarytenoid origin
from the inferoposterior aspect of the angle of the thyroid cartilage
Thyroarytenoid attaches
to the anterolateral part of the arytenoid cartilage.
function of the Thyroarytenoid
acts to relax the vocal
ligament, producing a softer voice
motor innervation to Thyroarytenoid
recurrent laryngeal nerve, a branch of the vagus nerve.
Cricothyroid origin
from the anterolateral aspect of the cricoid cartilage
Cricothyroid attaches
to the inferior margin of the
thyroid cartilage
function of Cricothyroid
stretches and tenses the vocal ligaments for the production of loud speech and different tones of voice
motor innervation to Cricothyroid
by the external laryngeal nerve, a branch of the superior laryngeal nerve
laryngospasm
rare but frightening experience. It occurs when the vocal folds (cords) suddenly seize up due to a disruption in nervous input from the laryngeal nerves, which can lead to an airway
obstruction. Although a laryngospasm can be an unnerving experience, it typically resolves itself within
a few minutes
Laryngospasms can be provoked
various triggers, such as asthma, allergies, exercise, irritants (e.g.
smoke, dust, fumes), stress, and/or anxiety. The most common trigger is gastroesophageal reflux
disease (G E R D )*.
thyroid gland
- found deep to musculature of the neck
- consists of right and left lateral
lobes with an isthmus that connects the lateral lobes and sits on the anterior surface of the trachea,
just inferior to the larynx
arterial supply of the thyroid gland
supplied by the superior thyroid artery and inferior thyroid artery,
superior thyroid artery,
branch of the external carotid artery,
inferior thyroid artery,
branch of the thyrocervical trunk which arises from the subclavian
artery
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 and descends anterior to the trachea
where do the superior and middle thyroid veins drain into
internal jugular vein
where does the inferior thyroid vein drain
brachiocephalic vein
what might be the source of bleeding in a tracheostomy
inferior thyroid vein
what is the thyroid gland regulated by?
the automatic nervous system and receive both sympathetic and parasympathetic innervation
what is the thyroid gland innervated by
vagus nerve
- specifically superior laryngeal and recurrent laryngeal nerve
sympathetic nerve fibers:
- comes from superior, middle, and inferior cervical ganglia of the sympathic trunk
goiter
abnormal enlargement of the thyroid gland at the inferior pole
- If it becomes significantly
enlarged, it can compress structures in the neck
Goiters have distinct symptoms
compresses structures around the neck
- cricothyroid
- vagus nerve
- trachea
- phrenic nerve
goiter Cricothyroid
The cricothyroid muscle stretches and tenses the vocal ligaments for the production of forceful speech
and tone. It may be compressed by an enlarged thyroid, altering the tone of an individual’s speech.
goiter Vagus Nerve
forms a cardiac pulmonary and esophageal plexus. If compressed by a goiter,
individuals may have difficulty breathing and swallowing.
goiter Trachea
The thyroid gland wraps around the anterior and lateral sides of the trachea. An enlarged thyroid gland
may compress the trachea and individuals can experience a “tightness” in the throat and unusual
coughing
goiter Phrenic Nerve
innervates the diaphragm and travels near the
thyroid gland. Hence, it can be compressed by an enlarged thyroid, leading to difficulty breathing.
superficial muscles of the neck
- located closest to the skin and allow for both gross and fine motor movements of the head, face, neck
two superficial muscles of the neck
sternocleidomastoid (SCM)
platysma
Sternocleidomastoid (S C M ) origin
inferiorly on the manubrium of the sternum and medial end of the clavicle
Sternocleidomastoid (S C M ) insert
superiorly on the mastoid process
Sternocleidomastoid (S C M ) function
flex the head and neck while individually
will tilt the head toward the shoulder on the same side rotating the head to turn the face to the
opposite side.
Sternocleidomastoid (S C M ) innervation
accessory (X I ) nerves*.
Platysma
Located in the subcutaneous tissue (superficial fascia), it runs from the upper two ribs to the lower
margin of the mandible. When it contracts, it tenses the skin of the neck and is responsible for facial
expression. Much of the anterior neck is covered by the two platysma muscles
deep muscles of the neck function
- stabilize and faciliate movement of the head, neck, and spine
- work together with the superficial muscles to promote good posture and mobility
deep muscles of the neck
Scalenes
Levator Scapulae
Scalenes
are the three muscles found in the deep lateral neck, spanning between the transverse processes of the cervical vertebrae and ribs 1 and 2.
Scalenes main functions
flex and rotate the neck. They are the accessory muscles of
respiration, elevating the ribs during forced inspiration.
Levator Scapulae
is a long muscle situated at the posterolateral neck
Levator Scapulae origin
on the
transverse processes of cervical vertebrae 1-4
Levator Scapulae insert
scapula
Levator Scapulae
lift the scapula and support the vertebral column
sternocleidomastoid (S C M ) syndrome.
When a trigger point develops within the S C M
sternocleidomastoid (S C M ) syndrome. Causes
Stress, overuse of the muscle, poor posture, and inactivity are common causes of trigger points
sternocleidomastoid (S C M ) syndrome. Symptoms
great pain in the lateral neck, jaw, posterior head, and throat (when
swallowing). Headaches, neck stiffness, and tingling in face or neck from the compression of nerves
may also be symptoms
The hyoid
U-shaped bone
The hyoid location
superior to the larynx and is attached by the thyrohyoid
membrane.
- not attached to any other bones it is suspended in the neck by muscles and ligament
muscles of the hyoid bone
suprahyoid (above hyoid bone)
infrahyoid (below hyoid bone) (strap muscles)
what are the 4 suprahyoid muscles
Digastric
Stylohyoid
Mylohyoid
Geniohyoid
Digastric
- has a posterior belly, that attaches to the mastoid process, and an anterior belly, that attaches to the mandible
Digastric intermediate tendon
running between the anterior and posterior bellies, is held by a fascial sling to the hyoid bone
Stylohyoid origin and insert
originates from the styloid process of the temporal bone, and inserts on to the hyoid bone
Mylohyoid
The paired mylohyoid muscles form the floor of the oral cavity by joining together at the midline raphe
Mylohyoid origin and insert
originate on the mandible and insert on the hyoid bone
Geniohyoid
- is medial and deep to the mylohyoid
- best visualized in the superior view
Geniohyoid origin and insert
originates from the mandible and inserts on to the hyoid bone.
POSTERIOR BELLY OF DIGASTRIC MUSCLE STRAIN
digastric muscle elevates the hyoid bone and assists with complex jaw motions such as speaking,
swallowing, breathing, and chewing. Interestingly, the two bellies of the digastric muscle are supplied
by different cranial nerves.
anterior belly of digastric muscle innervation
mandibular (V3) nerve
posterior belly of digastric muscle + stylohyoid muscle innervation
facial (VII) nerve.
strain in the posterior belly of the digastric muscle can occur from
overuse or jaw misalignment
strain in the posterior belly of the digastric muscle Symptoms
pain in the neck and under the chin. Pain may be also referred to the
sternocleidomastoid
the infrahyoid hyoid muscles
Sternohyoid
Omohyoid
Thyrohyoid
Sternothyroid
During swallowing and phonation the infrahyoid muscles
depress the hyoid bone and subsequently the larynx.
Sternohyoid (OI)
originates from the manubrium of the sternum and inserts on the hyoid bone
Omohyoid
- has two bellies
Omohyoid inferior belly OI
originates on the
scapula and inserts on the intermediate tendon
Omohyoid superior belly OI
originates at the intermediate tendon and inserts on the hyoid bone.
Omohyoid intermediate tendon
is attached to the clavicle by
a fascial sling
Thyrohyoid OI
originates from the thyroid cartilage and inserts on the hyoid bone.
Sternothyroid OI
originates from the manubrium of the sternum inserts on the thyroid cartilage.
Omohyoid muscle syndrome (OMS)
presents as a mass in the neck located superior to the clavicle that is only visible when the patient swallows
Omohyoid muscle syndrome (OMS) Symptoms
a stiff neck and tenderness when palpating near the mass.
Omohyoid muscle syndrome (OMS) causes
irritation or damage to the muscle, that may result from excessive vomiting or neck trauma.
internal carotid arteries supply what
brain and eyes
what does external carotid arteries supply
face and neck
where does subclavian arteries origate from
in the thorax
what do subclavian arteries supply
thorax, head, neck and upper limbs
on the left side of the body where does the subclavian artery arise from
directly from the aortic arch
where does the right subclavian arise from
brachiocephalic trunk
what does the internal Juglar vein drain
blood from the brain and from the superficial regions of the face and neck
what does the internal juglar vein connect to form and where
subclavian vein to form brachiocephalic vein at the junction of the neck and thorax
branches of internal juglar vein
- facial vein
- suprascapular vein
- superior thyroid vein
subclavian veins
originate at the outer border of the first rib as continuations of the axillary veins
- Given that the subclavian veins are large, central, and relatively superficial, they are often used to place central venous lines*.
what do subclavian veins play an important role in?
lymphatic drainage of the head and neck
branches of subclavian vein
- suprascapular vein
- external juglar
Central venous lines:
Used to administer medication or fluids that are unable to be taken by mouth or would harm a smaller peripheral vein; to obtain blood tests; to administer fluid or blood products for large volume resuscitation; to measure central venous pressure.
Atherosclerosis
refers to the buildup of fats, cholesterol, and other substances in arterial walls
Atherosclerosis causes
A buildup of plaque in the internal carotid artery (I C A ) may lead to narrowing and irregularity of the
artery’s lumen, preventing proper blood flow to the brain. As the narrowing worsens, pieces of plaque
in the I C A can break free, travel to the brain, and obstruct smaller vessels that supply the brain.
- reduced arterial supply to the brain, the individual may experience dizziness, headaches, confusion, fainting. I C A atherosclerosis can also lead to death if blood flow to the brain is significantly impaired.
lymphatic drainage of the head and neck is achieved by two main groups
a superficial ring of nodes at the junction of the head and neck (collar nodes) and two vertical groups of lymph nodes in the neck: superficial cervical and deep cervical lymph nodes
lymphatic drainage of the head and neck.
Superficial Nodes
Vertical Nodes
Jugular Trunk
Thoracic and Right Lymphatic Trunk
Superficial Nodes
The superficial ring of nodes includes the submandibular nodes and submental nodes inferior to the
chin.
Vertical Nodes
In the vertical groups of nodes, the superficial cervical nodes are found on the surface of the S C M
muscle and are associated with the external jugular vein while the deep cervical nodes are found deep
to the S C M and closely related to the internal jugular vein.
Jugular Trunk
Ultimately all lymphatic vessels of the head and neck drain into the deep cervical nodes. From the deep
cervical nodes, lymphatic vessels drain into the jugular trunks.
Thoracic and Right Lymphatic Trunk
The jugular trunks empty into the thoracic duct on the left side and the right lymphatic duct on the
right.
recurrent strep throat
Streptococcal pharyngitis, colloquially called “strep throat” is a bacterial infection of the pharynx. In an
immune response to the infection, the lymph nodes become enlarged.
symptom of strep throat
enlarged lymph nodes in the neck
- pain when swallowing, stiffness in neck, headaches, fever, sore
throat, and red palatine tonsils.
Otolaryngologist
specializes in disorders of the head and neck, particularly those
disorders related to the ears, nose, and throat. The word “oto-rhino-laryngology” comes from the
Greek words “oto” for ear, “rhino” for nose, and “laryn” for throat.
how do cranial nerve IX-XII enter the neck
from the skull, initially passing deep to the posterior digastric muscle
Glossopharyngeal nerve - CN IX pathway
The glossopharyngeal (I X ) nerve travels anteriorly, to provide sensory innervation to the tongue,
pharynx, and middle ear.
Hypoglossal nerve – C N X I I
The hypoglossal nerve (X I I ) curves anteriorly, passing deep to the posterior digastric muscle to supply
the muscles of the tongue.
vagus nerve location
in both the superior and posterior mediastinum
pathway of the vagus nerve.
Each vagus nerve (C N X ) descends through the neck, passing anterior to the subclavian artery to enter
the thorax.
Vagus nerve plexuses pathway
Both the right and left vagus nerves give rise to nerves that form the pharyngeal, parasympathetic
cardiac, pulmonary, and esophageal plexuses.
- vagus nerve also branches to form the superior laryngeal
nerves
right recurrent laryngeal nerve pathway
a branch of the right vagus nerve, loops around the right
subclavian artery and ascends in the groove between the esophagus and trachea to travel towards the
larynx
left recurrent laryngeal nerve pathway
branch of the left vagus nerve, loops beneath the arch of the
aorta around the ligamentum arteriosum and ascends in the groove between the esophagus and
trachea towards the larynx.
vocal fold paralysis.
Immobility of the vocal folds due to damage or dysfunction of their principal nerve
what does the recurrent laryngeal nerves innervate
the intrinsic muscles (except the cricothyroid) and the mucous membrane of the larynx between the vocal folds
Unilateral vocal fold paralysis (U V F P ) occurs from
a dysfunction of the recurrent laryngeal or the more upstream vagus nerve, and usually occurs as a result from blunt trauma.
- If the recurrent laryngeal nerve is damaged, an individual would exhibit symptoms that affect structures innervated by the recurrent laryngeal nerve. As such, this includes a swallowing disability, shortness of breath, a weak cough, and a hoarseness of the voice.
what innervate the infrahyoid muscles
cervical plexus
how is the thyrohyoid innervated
by C1 via the hpyoglossal nerve
The cervical plexus is formed by
the ventral rami of cervical spinal nerves 1-4
cervical spinal nerves 1-4. supply what
branches supply
motor innervation to most of the muscles of the neck and sensory innervation to the skin of the neck
and back of the scalp
INFRAHYOID MUSCLE PARALYSIS
Trauma to the cervical spine can damage the cervical plexus, resulting in muscular weakness from
damaged nerves or even paralysis of the infrahyoid muscles
- difficulties swallowing, a hoarse
voice, and tightness in the throat
what are major branches of the cervical plexus
right and left phrenic nerve providing motor and cutaneous innervation to the diaphragm
phrenic nerve on their way to the thoracic inlet
- each phrenci nerve crosses obliquely over the anterior surface of the scalene muscles and subclavian arteries
where do both phrenic nerves travel
into the thorax and pass between the heart and lungs towards the diaphragm
Right Phrenic Nerve pathway
- Passes anterior to the right subclavian artery;
- Enters the thorax through the thoracic inlet;
- Descends anterior to the right lung root;
- Courses along the pericardium of the right atrium of the heart;
- Pierces the diaphragm at the opening of the inferior vena cava.
Left Phrenic Nerve pathway
- Passes anterior to the left subclavian artery;
- Enters the thorax through the thoracic inlet;
- Descends anterior to the left lung root;
- Crosses the aortic arch and left vagus nerve;
- Courses along the pericardium of the left ventricle;
- Pierces and innervates the diaphragm.
phrenic nerve irritation
manifests as hiccups
causes associated with damage to the phrenic nerve(s).
Damage to the phrenic nerves may result from trauma to the neck or cervical vertebrae.
- Trauma to the skeleton of the thoracic inlet can also lead to phrenic nerve damage, since both the right
and left phrenic nerves travel through this aperture.
symptoms associated with damage to the phrenic nerve(s)
breathing, shortness of breath, or feeling faint.
nerves after leaving the spinal cord
form the sympathetic trunk
length of sympathetic trunk
spans the length of the vertebral column, from the base of the skull to the coccyx
how is the sympathetic trunk formed
by sympathetic nerve fibres and ganglia
what are 3 main sympathetic ganglia found in the cervical (neck region)
Superior Cervical Ganglion
Anterior view Middle Cervical Ganglion
Inferior Cervical Ganglion
where does each cervical sympathetic ganglion lie
medial to the phrenic nerve
Superior Cervical Ganglion
- The largest of the three ganglia
- is the superior cervical ganglion.
- positioned posterior
to the carotid arteries and anterior to the C 1- 2 vertebrae.
Anterior view Middle Cervical Ganglion
- The middle cervical ganglion is located anterior to the inferior thyroid artery and the C 6 vertebra.
- may be absent in some individuals.
Inferior Cervical Ganglion
situated anterior to the C 7 vertebra and is usually fused with the first
thoracic ganglion.
Horner’s Syndrome
disorder resulting from damage to the sympathetic innervation of the head,
namely the nerves leaving the cervical sympathetic ganglia.
causes of Horner’s Syndrome
spinal cord lesions or certain types of tumors
Symptoms of Horner’s syndrome
drooping of the upper eyelid, constriction of the pupil, and
absence of sweating on the face and neck.
laryngoscopy
A procedure that allows a physician to examine the back of the throat, the voice box (also called the larynx), and the vocal folds.
