Case 11 anatomy part 2 Flashcards
Trigeminal nerve
Cranial nerve 5. Has a Maxillary and Mandibular branch
Facial nerve
Cranial nerve 7
Special sensation- taste anterior 2/3 of the tongue
Parasympathetic- submandibular and sublingual glands
Glossopharyngeal nerve
Cranial nerve 9
Special sensation- taste posterior 1/3 of the tongue
General sensation- posterior 1/3 of the tongue, palatine tonsils, oropharynx
Motor sensation- Stylopharyngeus
Parasympathetic- parotid gland
Vagus nerve
Cranial nerve 10
Special sensation- taste from palate and epiglottis
General sensation- larynx
Motor- most of the muscles from the soft palate, larynx and pharynx
Parasympathetic- smooth muscle of the pharynx
Trigeminal maxillary branch (CNV2)
General sensation- palate and part of the nasopharynx
Trigeminal mandibular branch (CNV3)
General sensation- anterior 2/3 of tongue, floor of oral cavity, buccal mucosa
Motor- tensor veli palatini, mylohyoid muscle and muscles of mastication
Hypoglossal
Cranial nerve 12.
Motor- muscles of the tongue
Folds of the Larynx
1) Aryepiglottic fold- Mucosal folds over superior margins of the quadrangular membrane
2) Vocal folds (true vocal cords)- Mucosal folds over vocal ligaments
3) Vestibular folds (false vocal cords)- Mucosal folds over vestibular ligaments
4) Rima glottidis- Opening between vocal folds
5) Rima Vestibuli- Opening between vestibular folds
Three major regions of the Larynx
1) Laryngeal vestibule- Upper chamber between Laryngeal inlet & vestibular folds
2) Middle chamber- between vestibular folds & vocal cords
3) Infraglottic cavity- between vocal folds & inferior border of cricoid cartilage
Laryngeal ventricle
Recesses extending laterally from the middle part of the laryngeal cavity between the vestibular and vocal folds
Laryngeal saccule
A pocket opening into each ventricle, lined with mucosal glands
Extrinsic muscles of the larynx
Move the whole larynx
Swallowing
Infrahyoid & suprahyoid muscles
Intrinsic muscles of the larynx
1) Move the individual components of the larynx
2) Breathing and phonation
3) Cricothyroid, Thyro-arytenoid, Posterior crico-arytenoid, Lateral crico-arytenoid, Transverse arytenoid and Oblique arytenoid
Innervation of the intrinsic muscles of the larynx
Innervation: Vagus Nerve
Cricothyroid – Superior laryngeal branch of CNX
All other muscles – Recurrent laryngeal branch of CNX
Intrinsic muscle- Cricothyroid
Origin- cricoid cartilage
Insertion- thyroid cartilage
Action- pulls thyroid cartilage anterior and inferiorly. Stretches and tenses vocal ligaments to give a higher pitch
Innervation- External laryngeal nerve of the superior laryngeal nerve [CNX]
Intrinsic muscle Thyro-arytenoid
Origin- thyroid lamina and cricothyroid ligament.
Insertion- arytenoid cartilage
Action- Pulls epiglottis toward arytenoid cartilages; Pulls arytenoid cartilages anteriorly = Relaxes vocal ligament (lower pitch)
Innervation- inferior laryngeal nerve, terminal branches of recurrent laryngeal nerves (CNX)
Intrinsic muscles- Posterior cricoarytenoid
Origin- cricoid cartilage.
Insertion- arytenoid cartilage.
Action- abducts vocal folds, widens the rima glottidis
Innervation- the inferior laryngeal nerve, terminal branches of the recurrent laryngeal nerve (CNX)
Intrinsic muscles- Lateral cricoarytenoid
Origin- Arch of cricoid cartilage
Insertion- Muscular process of arytenoid cartilage
Action- adducts vocal folds (narrows the rima glottidis)
Innervation- inferior laryngeal nerve, terminal branches of recurrent laryngeal (CNX)
Intrinsic muscle- transverse and oblique arytenoids
Origin- Arytenoid cartilage
Insertion- Arytenoid cartilage
Action- Adducts arytenoid cartilage (closes posterior portion of rima glottidis)
Innervation- inferior laryngeal nerve, terminal branches or recurrent laryngeal nerve (CNX)
Intrinsic muscles- Vocalis
Origin- lateral surface of the vocal process of the arytenoid cartilage
Insertion- Ipsilateral vocal ligament
Action- relaxes posterior vocal ligaments whilst maintaining tension on anterior part
Innervation- Inferior laryngeal nerve, terminal branches of the recurrent laryngeal nerve (CNX)
Muscles responsible for pitch
1) Cricothyroid= principal tensor
2) Thyro-arytenoid= principal relaxers
Changing the tension on the vocal ligaments changes the pitch of the sound produced
Posterior crico-arytenoid function
Sole abductor, Antagonistic to lateral crico-arytenoids
Muscles responsible for phonation
1) Lateral crico-arytenoid (principal adductor)
2) Transverse and oblique arytenoid
When actions combined causes vibration of the vocal ligaments (phonation)
Larynx
A hollow tube with a cartilaginous framework. It found at the anterior aspect of the neck at the C3-C6 level. It connects the pharynx with the trachea. It guards the airway during swallowing so that food stuff does not enter the trachea. Important in sound producing. It is suspended from the Hyoid bone above.
The Laryngeal inlet
The opening of the larynx
Larynx - Quiet respiration
Arytenoid cartilage- abducted Rima glottidis- triangular Rima vestibuli- open Laryngeal inlet- open Muscles are relaxed
Larynx- forced inspiration
Arytenoid cartilage- laterally rotated, by action of posterior crico-arytenoids
Vocal folds- abducted
Rima glottidis- widened
Larynx- phonation
Arytenoid cartilage- adducted
Vocal folds- adducted
Rima glottidis- closed
By action of transverse and oblique arytenoids and lateral crico-arytenoids. Changes in pitch are due to vocalis, cricothyroid and thyro-arytenoid muscles
Larynx-swallowing
Rima glottidis- closed Rima vestibuli- closed Vestibule- closed Laryngeal inlet- narrowed The larynx moves up and forwards causing the epiglottis to swing down. The laryngeal inlet closes.
Blood supply to the right side of the larynx
Arch of Aorta –> Brachiocephalic artery –> Subclavian artery –> Thyrocervical trunk –> Inferior thyroid artery –> Inferior laryngeal artery
Blood supply to the left side of the larynx
Arch of Aorta –> Common carotid artery –> External carotid artery –> Superior thyroid artery –> Superior laryngeal artery
Blood supply to the internal surface of the larynx
The superior laryngeal artery
Blood supply to the Cricothyroid muscle
The Cricothyroid artery which is a branch of the superior thyroid artery
Blood supply to the mucosal membranes and the muscles of the inferior part of the larynx
The inferior laryngeal artery
Venous drainage on the right side of the Larynx
Superior laryngeal vein –> Superior thyroid muscle –> Internal jugular vein –> Brachiocephalic vein –> Superior vena cava
The venous drainage accompanies the arterial supply
Venous drainage on the left side of the larynx
Inferior laryngeal vein –> Inferior thyroid vein –> Left brachiocephalic vein –> Superior vena cava
The venous drainage accompanies the arterial supply
The recurrent laryngeal nerve supplies
1) The mucosa below the vocal folds
2) All intrinsic muscles of the larynx except the cricothyroid muscle
What does the superior laryngeal nerve supply
Divides into the external and internal laryngeal nerve. The internal laryngeal nerve supplies sensory information from the laryngeal mucosa above the vocal folds. The external laryngw
Lymphatic supply to the larynx
The laryngeal lymphatic vessels are above the vocal cord, they drain into the superior cervical lymph nodes. The lymphatic vessels below the vocal folds drain into the tracheal or Paratracheal lymph nodes. This then drains into the inferior deep cervical lymph nodes
The 5 paired muscles of the soft palate
- Tensor veli palatini
- Levator veli palatini
- Palatopharyngeus
- Palatoglossus
- Muscle of the uvula
Innervation of the soft palate
Motor innervation- the Vagus nerve (cranial nerve 10) apart from the tensor veli palatinia which is innervated by the medial pterygoid (a branch of the mandibular division of the trigeminal nerve, CN V3).
Sensory innervation- branches of the lesser palatine nerve (a branch of the maxillary division of the trigeminal nerve- CN V2).
The lentor veli palatini
Elevates the soft palate to close off the nasopharynx from the oropharynx during swallowing.
The circular muscles in the pharynx
Three constrictor muscles- the Superior pharyngeal constrictor, the Middle pharyngeal constrictor
The longitudinal muscles in the pharynx
They are composed of three paired muscles: Palatopharyngeaus, Stylopharyngeus and Salpingopharyngeus.
Where do the nerves to the Pharynx originate from
The Pharyngeal plexus
Motor innervation to the pharynx
Most of the muscles of the pharynx are innervated by the Vagus nerve (cranial nerve 10). The Stylopharyngeus muscle is supplied by the glossopharyngeal nerve (cranial nerve 9).
Sensory innervation to the pharynx
Primarily from the Glossopharyngeal nerve (cranial nerve 9). There are a few exceptions:
• The anterior and superior aspect of the nasopharynx is innervated by the maxillary division of the trigeminal nerve (CNV2)
• The inferior aspect of the laryngopharynx (the valleculae and surrounding the beginning of the larynx) is innervated by the internal branch of the vagus nerve (CNX).
Blood supply to the pharynx
Via branches of the external carotid artery. This includes the ascending pharyngeal artery and branches of the facial, lingual and maxilary artery
Venous drainage of the pharynx
Achieved by the pharyngeal venous plexus which drains into the internal jugular vein
