Topic 5 - Pharynx, Tongue And Palate Flashcards
What is a nerve plexus?
A nerve plexus is a network of intersecting nerve fibres or blood vessels that serve the same part of the body.
Give a general description of how the pharyngeal plexus is formed.
The pharyngeal plexus is formed by fibres branching off the glossopharyngeal, vagus and accessory nerves (CN IX, X, XI)
All sensory fibres in the pharyngeal plexus join the glossopharyngeal nerve (IX), while motor fibres arise from both the vagus (X) and accessory nerves (XI)
What is an aponeurosis?
Aponeurosis is a sheet of pearly white fibrous tissue that takes the place of a tendon in flat muscles having a wide area of attachment.
Which muscle forms the palatine aponeurosis, and which muscles attach to the palatine aponeurosis?
The palatine aponeurosis is formed by the expanded tendon of the tensor veil palatine muscle.
Attached to the posterior border of the hard palate, the palatine aponeurosis, supports the muscles and gives strength to the soft palate.
Describe the detailed innervation of the tongue
All motor innervation to the tongue (except the palatoglossus muscle) is via CN XII (Hypoglossal nerve).
The palatopglossus is innervated by CN XI (accessory nerve).
Anterior 2/3 special sensory (taste) - CN VII (facial nerve)
Anterior 2/3 general sensory - CN V (trigeminal nerve)
Posterior 1/3 special sensory (taste) - CN IX (glossopharyngeal)
Posterior 1/3 general sensory - CN IX (glossopharyngeal)
Which artery supplies blood to the tongue?
The arterial blood supply to the tongue is from the lingual artery, a branch of the external carotid artery.
It forms several branches to supply different regions of the tongue.
Venous drainage is by the deep lingual veins which drain into the internal jugular vein.
Name and describe the attachments and actions of the extrinsic tongue muscles
The tongue has 2 groups of muscles responsible for the movements of the tongue.
The extrinsic muscles attach to the tongue and external structures
The intrinsic muscles are found within the body of the tongue.
There are 4 paired muscles in each group. Extrinsic: 1- genioglossus 2- hyoglossus 3- styloglossus 4- palatoglossus
Intrinsic: 1- Superior longitudinal 2- Inferior longitudinal 3- Transverse 4- Vertical
Describe the major movements that the soft palate is capable of, with reference to the muscles of the soft palate.
The soft palate is the posterior muscular part of the palate that can be moved to perform different functions.
The soft palate separates the oropharynx from the nasopharynx and is involved in changing the volume and shape of the oral and nasal cavities. It plays an important part in articulation of sounds.
5 muscles involved in the movements of the soft palate:
1- Tensor veil palatini - attaches to the sphenoid bone, part of the auditory tube and on the soft palate forms of the palatine aponeurosis. It is the major tensor of the soft palate, contributes to the opening of the auditory tube.
2- Levator veil palatini - attaches to the temporal bone, part of the auditory tune, and the palatine aponeurosis. It elevates the soft palate and contributes to opening the auditory tube.
3- Palatoglossus - found inside the palatoglossal arch. It attaches to the palatine aponeurosis and sides of the tongue and is a depressor of the soft palate. It can also elevate the sides of the tongue.
4- Palatopharyngeus - found inside the palatopharyngela arch. It is continuous with he pharyngeal wall and attaches to the hard palate and palatine aponeurosis. It is a depressor of the soft palate and a pharyngeal elevator.
5- Uvular muscle - short muscle found in the body of the uvula. It shortens the uvula and pulls the uvula superiorly.
Which muscles are responsible for rolling up the sides of your tongue?
Superior longitudinal muscle curls sides of tongue
Muscles of the tongue and their actions
Genioglossus - extrinsic- depresses + protrudes tongue
Hyoglossus - extrinsic- depresses + retracts tongue
Styloglossus - extrinsic- elevates + retracts tongue
Palatoglossus- extrinsic- elevates posterior part of tongue
Superior longitudinal - intrinsic- curls tip + sides superiorly + shortens tongue
Inferior longitudinal - instrinsic- curls tongue tip inferiorly + shortens tongue
Transverse - intrinsic- narrows + elongates tongue
Vertical - intrinsic- flattens + broadens tongue
Describe the muscles that make up the floor of the mouth
The suprahyoid muscles are located in the floor of the mouth.
They function to elevate the hyoid and larynx, as well as stabilising the hyoid bone during swallowing.
These muscles are:
1- mylohyoid
2- geniohyoid
3- stylohyoid
4-digastric
What is the function of rugae on the hard palate?
On the anterior portion of the roof of the hard palate are the transevese palatine folds (rugae) which are the irregular ridges in the mucous membrane that help facilitate the movement of food backwards towards the pharynx.
Where are the pharyngeal tonsils located?
The roof and posterior wall of the nasopharynx contains the pharyngeal tonsils (adenoids).
Name the muscles which elevate the pharynx
The internal layer of the pharyngeal wall has 3 muscles which elevate the pharynx:
1- palatopharyngeus - narrows + elevates the pharynx and lowers the soft palate. Attaches to the hard palate and palatine aponeurosis superiorly + thyroid cartilage interiorly
2- salpingopharyngeus - elevates lateral pharyngeal wall. Also opens the pharyngotympanic tube. Attaches superiorly to the pharyngotympanic tube and interiorly blends with palatopharyngeus.
3- stylopharyngeus - elevates and opens pharynx. Attaches to the styloid process superiorly and blends with palatopharyngeus and thyroid cartilage inferiorly.
Name the pharyngeal constrictor muscles
1- superior constrictor - narrows upper pharynx during swallowing
2- middle constrictor - narrows middles pharynx during swallowing
3- inferior constrictor - narrows inferior pharynx during swallowing
Where is the lingual septum located?
The lingual septum lies deep to the central sulcus. This is a fibrous septum that is important for muscle attachment.
Name a muscle that protrudes the tongue
The genioglossus protrudes and depresses tongue.
The hyoglossus depresses + retracts tongue
The styloglossus elevates + retracts tongue
The palatoglossus elevates posterior part of tongue
Venous drainage from the tongue occurs from the deep lingual veins.
True or false?
True
Venous drainage is by the deep lingual veins which drain into the internal jugular vein.
The arterial blood supply to the tongue is from the lingual artery, a branch of the external carotid artery.
What are the differences between the tensor veli palatini and the levator veli palatini, in both function and attachements?
The tensor veli palatini muscle is innervated by the mandibular division of the trigeminal nerve
The levator veli palatini muscle elevates the soft palate and is innervated by the pharyngeal plexus.
The tensor veli palatini tenses the soft palate by elevating and pulling tight and by doing so, assists the levator veli palatini in elevating the palate to occlude and prevent entry of food into the nasopharynx during swallowing.
What is lingual septum?
Is it different to the lingual frenulum?
Lingual septum lies deep to the central sulcus. It is a fibrous septum that is important for muscle attachment.
Lingual frenulum
- is a structure that connects the tongue to the floor of the mouth. It is visible when the tongue is raised.
- is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the tongue
Which tonsils are found in the roof or wall of the nasopharynx?
The roof and posterior wall of the nasopharynx contains the pharyngeal tonsils (adenoids).
Tonsils are bundles of lymphoid tissue designed to trap foreign particles and miscoorganisms entering the nasal and oral cavities.
What is the function of the levator veli palatini?
Levator veli palatini elevates the soft palate and pulls it slightly backwards. This action together with the action of musculus uvulae closes the passage between the nasopharynx and oropharynx, facilitating the act of swallowing and preventing the food from passing to the nasopharynx.
What is the musculus uvulae?
The uvular muscle is the short muscle found in the body of the uvula. It shortens the uvula and pulls the uvula superiorly.
The musculus uvulae is an intrinsic muscle of soft palate;
origin - posterior nasal spine;
insertion - forms chief bulk of the uvula;
action - raises the uvula;
nerve supply - pharyngeal plexus.
What are the faucial pillars?
Type of ridge of mucous membrane that passes downward from posterior margin of soft palate to lateral wall of pharynx.
Also called the palatopharyngeal arches
