Head, Neck Muscles (COPIED OVER) Flashcards
What is the origin of sternocleidomastoid?
The manubrium of the sternum and the clavicle.
What is the insertion of sternocleidomastoid?
Mastoid process.
How many parathyroid glands are there?
4
Where are the parathyroid glands located?
Posterior surface of thyroid glands.
Name 3 functions of the larynx.
- Phonation.
- Cough reflex.
- Protection of the lower respiratory tract.
What is the epithelium of the vocal folds? and why?
Stratified squamous epithelium. This is more robust and can withstand the vibrations and wear and tear.
What does the recurrent laryngeal nerve supply?
Motor innervation to intrinsic muscles of the larynx (except cricothyroid).
What does the internal branch of the superior laryngeal nerve supply?
Sensory innervation to larynx above vocal folds.
What does the external branch of the superior laryngeal nerve supply?
Motor innervation to the cricothyroid muscle.
Name the 3 unpaired cartilages in the larynx
- Epiglottis (elastic cartilage).
- Thyroid (hyaline cartilage).
- Cricoid (hyaline cartilage).
What do the two sheets of thyroid cartilage form in the midline?
The laryngeal prominence (Adam’s apple).
What do the superior horns of the thyroid cartilage articulate with?
The hyoid bone.
Name the 3 paired cartilages in the larynx.
- Arytenoid.
- Cuneiform.
- Corniculate.
Where are cuneiform cartilages located?
Within the ary-epiglottic folds. They strengthen the folds.
What is the space between the vocal cords called?
Rima glottidis.
What is the superior vestibular folds also known as?
False vocal folds.
What are the extrinsic muscles of the pharynx?
The suprahyoids, infrahyoids and stylopharyngeus.
What is the function of the extrinsic muscles of the larynx?
They move the larynx superiorly and inferiorly during swallowing.
What is the innervation of the intrinsic laryngeal muscles?
Recurrent laryngeal nerve.
What intrinsic laryngeal muscle is not innervated by the recurrent laryngeal nerve?
Cricothyroid.
What is the innervation of the cricothyroid muscle?
External branch of the superior laryngeal nerve.
What is the function of the cricothyroid muscles?
It tips the thyroid cartilage anteriorly and inferiorly.
Increases tension of vocal folds.
What nerve passes through the parotid gland?
The facial nerve - Cn 7.
Where does the pharynx extend from and to?
The base of the skull to the cricoid cartilage (C6).
What are the 3 sections of the pharynx called?
- Nasopharynx.
- Oropharynx.
- Laryngopharynx.
What is the function of the pharyngeal constrictor muscles?
They contract sequentially to propel food into the oesophagus.
What is the innervation of the pharynx?
The pharynx is innervated by sensory fibres from the glossopharyngeal nerve and motor fibres from the vagus nerve.
Where is the carotid sinus located? Function?
At the bifurcation of the common carotid artery. They contain baroreceptors that monitor arterial blood pressure. This visceral sensory information is relayed back via the glossopharyngeal nerve.
Where does the glossopharyngeal nerve exit the cranial cavity?
Through the jugular foramen.
What does elevation of the soft palate do?
It closes the orifice between the nasopharynx and oropharynx. This occurse during swallowing to prevent food refluxing into the nose. It also occurs in phonation.
What is the function of the tonsils?
The tonsils are a consolidation of lymphoid tissue. They prevent infection by stopping germs entering the mouth and nose.
Give 4 functions of the nasal cavity.
- Warms and humidifies air.
- Olfaction.
- Removes and traps pathogens.
- Drains and clears para-nasal sinuses.
What is the function of the nasal conchae?
They increase the SA of the nose and they disrupt the fast flow of air. This means the air spends more time in the nasal cavity so it can be humidified.
Why does the nose have a rich vascular supply?
This means it can change the humidity and temperature of inspired air.
Give 4 functions of the paranasal sinuses.
- Lighten the head.
- Warm and humidify air.
- Speech resonance.
- Protection against facial trauma.
What level does the Thyroid gland sit?
C5/C6
What arteries supply blood to the thyroid?
Superior Thyroid artery - branch of the External carotid
Inferior thyroid artery - the thyrocervical trunk, a branch of the subclavian artery
What doe the sinuses drain into?
The Superior, middle and inferior Meatus.
(they are the pockets of space found just underneath the Conche)
Why is the maxillary sinus more prone to infection?
The opening into the nasal cavity is at the top of the sinus so it does not drain easily
What are the attachments of the muscles of the tongue?
The hyoid bone
What structure stops reflux of liquid into the nose during swallowing?
The soft palate
What is the function of the soft palate?
The function of the soft palate is to
control the orifice between the nasal and oral parts of the pharynx. Elevation of the soft palate
closes the orifice and this occurs during swallowing to stop reflux of food into the nasopharynx
and during phonation to allow the production of explosive consonants.
What is the function of the Eustachian tube?
To equalize the air pressure either side of the tympanic membrane
What provides taste sensation to the epiglottis?
Superior Laryngeal nerve, a branch of the vagus
What are the recurrent laryngeal nerves?
The left and right recurrent layrngeal nerves arise from the L/R vagus nerves, respectively.
LRLN loops under arch of the aorta.
RRLN loops under the right subclavian artery, just after the brachiocephalic right trunk.
They innervate the L/R muscles of the larynx, respectively.
What is the function of the arytenoid cartilages?
Movements of the arytenoid cartilages moves the vocal cords. They are vital for phonation.
What is the innervation of the sternocleidomastoid muscle?
Accessory nerve (CN XI)
What are the boundaries of the anterior triangle?
anteriorly: the midline of neck
posteriorly: the anterior border of sternocleidomastoid
superiorly: the lower border of the mandible
What are the borders of the posterior triangle?
anteriorly: the posterior border of sternocleidomastoid
posteriorly: the anterior border of trapezius
inferiorly: the clavicle.
What are the borders of the posterior triangle?
anteriorly: the posterior border of sternocleidomastoid
posteriorly: the anterior border of trapezius
inferiorly: the clavicle.
Function and blood supply of the parathyroid glands
They produce parathyroid hormone which plays a role in calcium regulation.
They are typically supplied by the inferior thyroid arteries.
How is the superior vena cava formed?
Internal jugular vein unites with the subclavian vein to form the brachiocephalic vein.
The R and L brachiocephalic veins unite to form the superior vena cava.
Where does the internal jugular vein drain?
The brain and part of the face.
Where does the subclavian vein drain?
Blood from the upper limb.
Where does the glossopharyngeal nerve supply?
The glossopharyngeal nerve (CN IX) supplies the:
● pharynx (sensory innervation)
● carotid sinus (visceral sensory fibres that return to the CNS via CN IX)
- Parasympathetic fibres to parotid gland
Where does the vagus nerve supply in the neck?
The vagus nerve (CN X) is vital for normal speech and swallowing. It supplies:
● the muscles of the pharynx (motor innervation)
● the larynx (motor and sensory innervation) via branches.
What nerve supplies the platysma?
The facial nerve (CN VII)
What comprises the carotid sheath?
- Vagus nerve (runs in the middle)
- Internal jugular vein
- Common carotid (below the bifurcation) OR the internal carotid (above bifurcation).
What does the accessory nerve supply?
The accessory nerve (CN XI) supplies the sternocleidomastoid and trapezius muscles.
What does the hypoglossal nerve supply?
The hypoglossal nerve (CN XII) is motor to the muscles of the tongue.
It lies lateral to the internal carotid artery and deep to the external jugular vein.
How does phonation work?
Intrinsic muscles of the larynx move the laryngeal cartilages which in turn move the vocal cords that lie inside the larynx.
How do the posterior cricoarytenoids aid in phonation?
They attach to the arytenoids. These muscles abduct the vocal cords and open the rima glottidis.
How do the transverse arytenoids aid in phonation?
They connect the two arytenoid cartilages. These muscles adduct the vocal folds and close the rima glottidis.
What nerves stimulate the salivary glands?
Parotid - parasympathetic fibres of the glossopharyngeal nerve.
Submandibular - parasympathetic fibres of the facial nerve.
Sublingual - parasympathetic fibres of facial nerve.
