A L3 - Flashcards
What are the 2 main triangles of the neck - what muscles divides it into these?
What are the boundaries of the anterior triangle?
What are the triangles within the anterior triangle and their boundaries?
- Posterior and anterior
- The SCM
ANTERIOR BOUNDARIES:
– Mandible
– SCM
– Imaginary midline of neck
– Apex - where SCM meets imaginary midline
Anterior Triangles:
– Submental (Hyoid bone, anterior digastrics)
– Submandibular ( Mandible, anterior and posterior digastric)
– carotid (SCM, superior belly of omohyoid, posterior digastric)
– Muscular (midline of neck, hyoid bone, SCM, superior omohyoid)
Origin + Insertion + action + nerve supply of SCM
O- Manubrium of sternum and medial 1/3 of clavicle
I- Mastoid process of skull
A - Rotates neck so face is turned superiorly to opposite side, tilts head laterally, flexes neck
N- Accessory nerve, upper cervical nerves
What are the infrahyoid muscles?
Origin + Insertion + action + nerve of them?
Muscles situated below the hyoid bone:
Omohyoid
O- superior border of scapula near the suprascapular notch
I- hyoid bone
A - depressed hyoid bone
N- cervical nerves
Sternohyoid
O- Manubrium of sternum
I- Hyoid bone
A - depresses the hyoid bone after swallowing
N- cervical nerves
Sternothyroid
O- Manubrium of sternum
I- thyroid cartilage
A - depresses larynx
N- cervical nerves
Thyrohyoid
O- Thyroid cartilage
I- hyoid bone
A - depresses hyoid bone
N- cervical nerves
What are the suprahyoid muscles?
Origin + Insertion + action + nerve of them?
Muscles that lie superior to the hyoid bone:
Digastrics:
O- Anterior —> Inner surface of mandible Posterior –> Mastoid process of skull
I- Intermediate tendon
A - Elevates hyoid bone ( directly up)
N- Anterior—> Mandibular division of trigeminal nerve (V3) Posterior —> Facial nerve
Mylohyoid:
O- Inner surface of mandible of each side
I- Hyoid bone and raphe
A - Elevates hyoid bone (up and forwards)
N- nerve to mylohyoid (branch of mandibular division of trigeminal n. - V3)
Stylohyoid:
O- Styloid process
I- Hyoid bone
A - Elevates hyoid bone (up and backwards)
N- Facial nerve
Geniohyoid:
O- Inner surface of mandible
I- Hyoid bone
A - Elevates hyoid bone (up and forwards)
N- cervical nerves
What is the only infrahyoid muscle that doesnt depress the hyoid bone?
The sternothyroid
it depresses the larynx
What muscles elevate the hyoid bone? what muscles depress them?
The suprahyoid elevate them and the infrahyoid depress them
What muscle depresses the larynx?
the sternothyroid muscle
Which suprahyoid muscles supplied by facial nerve?
The posterior digastric and stylohyoid
Which musc. helps open mouth?
Digastrics
Which musc. helps in swallowing?
The mylohyoid and the sternohyoid
Which musc. depresses the mandible?
geniohyoid
Which suprahyoid muscles supplied by mandibular division of trigeminal nerve?
Mylohyoid (nerve to mylohyoid)
anterior digastric
What are strap muscles?
What structure is responsible for voice production? what is continuous with above and below?
Larynx
Above - laryngopharynx
Below - trachea
What are the cartilages of the larynx? Which are paired and unpaired?
UNPAIRED:
Thyroid cart.
Cricoid cart.
Epiglottis
PAIRED:
Arytenoids
cuneiforms
Corniculates
Which is the only cartilage that forms a complete ring?
cricoid
Which cartilage forms the adam’s apple? why is this more prominent in males?
thyroid - the laryngeal prominence (formed by the fusion of the 2 thyroid laminae)
– More prominent in males because the angle made my the laryngeal prominence is more acute in males.
What is the anterior aspect of the cricoid cartilage called?
cricoid arch
What two part of the thyroid cartilage fuse to form the laryngeal prominence?
The two Laminae
How many processes do the arytenoid cartilages have? Which one of these is attached to the vocal cords?
They have 3 processes (vocal processes and muscular processes)
The anterior processes (vocal) are attached to vocal cords
What do the vocal cords/ligaments attach to?
Anterior processes of arytenoid cartilages and the posterior aspect of the thyroid cartilage
Which borders of the epiglottis are free? and where is attached?
The lateral and superior borders
inferiorly to the posterior aspect of the thyroid cartilage
Where do the paired cartilages (apart from arytenoid) lie?
in the Aryepiglottic fold
Name all the membranes of the larynx and what they are attached to/link together.
Cricothyroid membrane
Quadrangular membrane
Hyo-epiglottic fold
Thyrohyoid membrane
Cricotracheal membrane
What forms the vocal ligament?
The upper border of the cricothyroid membrane
What forms the vestibular ligament?
The lower border of the quadrangual membrane
What forms the true vocal cord/vocal fold and the false vocal cords?
Mucosal layer covering
Which membrane is frequently pierced in states of emergency where theres something blocking their airway above the level of the vocal cords?
What is this called?
The median cricothyroid ligament is pierced – cricothyroidectomy.
– Thickening of the cricothyroid ligament in front
What is the laryngeal inlet?
What are its boundaries?
Entrance into larynx
Epiglottis
Aryepiglottic folds
Interarytenoid folds
What is the aryepiglottic fold? Which structures are suspended in this?
It is a fold in the mucosa passing from the lateral borders of the epiglottis posteriorly to the arytenoid cartilages
It contains the cuneiform and the corniculate cartilages
What is epiglottitis? What cld it result from? What structure does it narrow? What cld this result in?
Inflammation of epiglottis that may result from a viral infection of the larynx
– swelling narrows the laryngeal inlet which may result in breathing difficulties and require an emergency airway
What are the 3 compartments of the larynx and their borders? What divides the larynx into these?
Vestibule:: Laryngeal inlet –> False vocal folds
Ventricle:: False vocal/Vestibular fold –> True vocal fold
Infraglottic cavity:: True vocal folds –> C6 level - it’s continuous with trachea
What makes up the:
Glottis
Supraglottis
Subglottis
Glottis:: The true vocal folds and the rima glottidis
Supraglottis:: space above the true vocal folds (ventricle + vestibule)
Subglottis:: space below true vocal folds (infraglottic cavity)
What are the spaces between the true and false vocal cords called?
true vocal cords:
– Rima glottidis
False vocal cords:
– Rima vestibuli
What are the joints of the larynx? What type?
Articulations? What type of movement occurs at them? What do they do?
Synovial joints::
- Cricothyroid –> btwn cricoid and thyroid cartilages
– move back and forth to alter vocal cord tension and length - Cricoarytenoid –> btwn cricoid and arytenoid cartilages
– slide and rotate to narrow or widen rima glottidis
What are the intrinsic musc of larynx attached to? What are their 2 broad functions?
Muscles that alter the size and shape of the laryngeal inlet.
Muscles that alter the vocal cords - alter length and thus tension, abduct/adduct vocal cords.
What intrinsic muscles:
- Alter tension of VCs
- Abduct VCs
- Adduct VCs
Tension:: Cricothyroid (vaires pitch). + Vocalis (vaires tonal qualities - used for animated speech)
Abduction:: posterior cricoarytenoids
Adduction:: lateral cricoarytenoids + Transverse arytenoid muscles
What is the function of cricothyroid muscles? Nerve supply?
external branch of superior laryngeal nerve
Alter tension and length of VCs – regulate pitch of voice
Which muscle is responsible for animated speech?
Vocalis muscle
What do the posterior and lateral cricoarytenoid musc do?
Posterior – abduction
Lateral – adduction (also transverse arytenoid)
Someone has lost the high pitch of their voice – What has most likely happened? What surgical procedure could have resulted in this and why?
Damage to the external laryngeal nerve – supplied the cricothyroid muscle which regulates tension of vocal cords and thus pitch of the voice
- Can occur during thyroid surgery
- Nerve is closely related to the superior thyroid artery
- So can be damaged during thyroid surgery
Muscles that change size and shape of inlet?
– aryepiglottic musc.
– thyroepiglottic musc.
– oblique and transverse arytenoids.
Muscles that abduct/adduct/change tension of vocal cords
Change tension::
- Vocalis – used in animated speech.
- Cricothyroid – changes tension to increase the pitch of voice.
Abduct::
- Posterior cricoarytenoid
Adduct::
- Lateral cricoarytenoid
- Transverse arytenoid.
What structure are the external laryngeal nerves closely related to?
Superior thyroid arteries
What nerve(s) provides innervation to the larynx?
Motor:
External laryngeal nerve (branch of superior laryngeal n. which is a branch of vagus):
— Supplies the cricothyroid muscle which controls the tension of the vocal cords. —-> Injury to this nerve prevents high pitch of voice.
Recurrent laryngeal nerve (branch of vagus):
— Supplies all intrinsic muscles of larynx apart from the cricothyroid. —> Damage to this nerve will affect muscles that cause adduction and abduction of vocal cords and alter size and shape of laryngeal inlet
Sensory:
Mucous memb. above true vocal folds :
– Internal laryngeal nerve (branch of superior laryngeal n. of vagus n.)
Mucous memb. below true vocal folds :
– Recurrent laryngeal n. (branch of vagus n.)
Describe the motor innervation to the larynx. What happens if these nerves are injured?
External laryngeal nerve (branch of superior laryngeal n. which is a branch of vagus):
— Supplies the cricothyroid muscle which controls the tension of the vocal cords. —-> Injury to this nerve prevents high pitch of voice.
Recurrent laryngeal nerve (branch of vagus):
— Supplies all intrinsic muscles of larynx apart from the cricothyroid. —> Damage to this nerve will affect muscles that cause adduction and abduction of vocal cords and alter size and shape of laryngeal inlet
Describe the sensory innervation to the larynx.
Mucous memb. above true vocal folds :
– Internal laryngeal nerve (branch of superior laryngeal n. of vagus n.)
Mucous memb. below true vocal folds :
– Recurrent laryngeal n. (branch of vagus n.)
Damage to which nerve would result in a problems of abduction, adduction of vocal cords and changing size and shape of laryngeal inlet
recurrent laryngeal nerves
(branches of this nerve supply all intrinsic musc. of larynx except cricothyroid)
Which nerve supplies sensory innervation to the mucous membrane below the vocal folds and which one above?
Mucous memb. above:
– Internal laryngeal nerve (branch of superior laryngeal n. of vagus n.)
Mucous memb. below:
– Recurrent laryngeal n. (branch of vagus n.)
Pathway of vagus nerve? Its innervation in the thorax and path of right and left vagus nerves?
Branches of vagus nerve?
- Pharyngeal branch (motor innervation to most of the pharynx and soft palate)
- Superior laryngeal n. (External and internal branches)
- Recurrent laryngeal
What do the vagus nerves provide parasympathetic innervation to?
Provides parasympathetic innervation to the thoracic viscera and carries sensory fibres from here.
What structure do the vagus nerves do they pass to enter the superior mediastinum and from where?
Vagus nerves enter the superior mediastinum by passing posterior to the brachiocephalic veins.
Pathway of right and left vagus nerves
What do the vagus nerves pass thru to enter the abdomen?
Pass thru the diaphragm via the T10 opening.
Where do the left and right recurrent laryngeal nerves branch off and where do they pass through?
right – loops under r subclavian
left – loops under aortic arch
What type of injuries/diseases are more likely to affect the left vagus only?
- Disease of the thorax – ex. cancer of the thorax - leads to enlarged lymph nodes and more likely to compress left vagus over right.
- Aneurysm in the aortic arch – in the area of the aortopulmonary window – compresses left vagus.
What type of injuries/diseases are more likely to affect the right vagus only?
— Cancer of the right apex of the lung - can result in injury/compression of R. vagus.
What groove do the right and left recurrent laryngeal nerves ascend in?
Descend in the groove btwn the oesophagus and trachea.
what procedures can risk damage to both recur. laryng. nerves? and why?
Carcinoma of the oesophagus – may affect recurrent laryngeal nerves
Surgery to the thyroid gland – Injury to thyroid arteries may result in injury to recurrent laryngeal nerves or the internal and external laryngeal nerves.
—- Recurrent laryngeal n - inferior TA
—- External L.n. - Superior TA
—- Internal L.n. - superior laryngeal A.
What is the blood supply to the larynx by?
– Superior laryngeal artery (branches of superior thyroid which is a branch of ECA)
– Inferior laryngeal artery (branch of Inferior thyroid A. which is a branch of subclavian A.)
Laryngoscopy - What is it? Why is it done? What are the 2 types?
What is the piriform fossa? where? clinical significance?
located of either side of the epiglottis at the entrance to the larynx
sharp ingested bodies can get dislodged here like fish bones
what may result in the hoarseness/loss of voice?
Damage to external laryngeal nerve (supplies cricothyroid)
How many groups of lymph nodes in the neck? Name them and where they’re located?
8 cervical lymph nodes
In the mediastinum, name the vessels which cross the trachea on each side.
Arch of aorta on left side and arch of the azygos vein on right side
What structures are the following closely related to:
- external laryngeal n. (branch of superior laryngeal n)
- recurrent laryngeal nerves
- Internal laryngeal n.
- external laryngeal n. –> superior thyroid A.
- recurrent laryngeal nerves –> Inferior thyroid A.
- Internal Laryngeal n —> Superior laryngeal A. (branch of sup. Thyroid A.)
