Mouth to Oesophagus Flashcards
what are the cranial nerves that you need to know
- trigeminal
- facial
- glossopharyngeal
- vagus
- hypoglossal
how many paired cranial nerves are there
- Cranial nerves are 12 paired nerves that originate from the brain or the brain stem
what is the role of cranial nerves
- Mainly involved in sensory and motor that is in the head and neck
what is the skeleton of the jaw made up of
- Made out of the mandible and the maxilla
describe the structure of the mandible
- Main part is called body
- Inferior teeth are in it
- In the side of the mandible, superiorly it has two different processes which are the coronoid process(this is a muscle attachment point) and the head(this forms the temporomandibular joint)
- Neck is below the head, this is a narrow part of the bone
- Ramus
- When the ramus meets the body is an angle
- Internally there is a mandibular foramen, and the nerve that supplies the inferior teeth runs through this mandibular foramen
- Also have the mental foramen
what are the two different processes on the side of the mandible
the coronoid process(this is a muscle attachment point) and the head(this forms the temporomandibular joint)
what are the foramen that are present in the mandible
- mandibular foramen
- mental formanet
what is the role of the lips
- lips control what goes into the the mouth and what doesn’t go into the mouth
describe the muscles that make up the lips
- Lips contain circular fibres and is skeletal muscle – this is called orbicularis oris
- this is one of the muscle of facial expression
what is the muscle called that makes up the cheek
Buccinator is also a muscle of facial expression which makes up the cheek, this is just behind orbicularis oris
what nerve innervates the orbiculares oris
facial nerve
- this is the nerve that innervates the muscles of facial expression
where does the facial nerve start
- The start of the facial nerve is just below the ear lobe, it splits into the 5 facial branches and supplies the facial muscles
describe what happens if you get damage to the facial nerve
- If you get damage to the facial nerve this can lead to paralysis of facial expression on that side of the face –bells plausy
what does the Trigeminal nerve do
- Provides sensory innervation for the entire face
what are the 3 divisions of the trigeminal nerve
ophthalmic(V1),
maxillary(V2)
mandibular(V3)
what innervates the teeth
- They are innervated by the maxillary (upper teeth) and mandibular branches (lower teeth) of the trigeminal nerve
what is the sensory innervation to the lower teeth
Inferior alveolar nerve – sensory innervation to lower teeth – branch of mandible – runs through the mandibular foramen,
what goes through the mental foramen
terminal branch of the inferior alveolar nerve goes through mental foramen and provide sensory innervation to the
what is the sensory innervation to the superior teeth
- Superior alveolar nerve
what are the muscles of mastication
- The muscles of mastication are a group of muscles, that are all innervated by the Mandibular branch of the Trigeminal nerve.
what are the muscles of mastication all innervated by
innervated by the Mandibular branch of the Trigeminal nerve.
what do the muscles of mastication do
- They collectively move the mandible with respect to the facial skeleton, they are attached to the mandible
what muscles make up the muscles of mastication
- Two major muscles are temporalis and masseter
- Two other muscles that are found on the internal aspect of the mandible and these are the lateral and medial pterygoid
what is the role of the temporalis muscle of mastication
- Elevation (anterior fibres of the temporalis) and retraction (posterior fibres of the temporalis) of the jaw
what is the role of the masseter muscle of mastication
- Elevation and protrusion
Lateral pterygoid
what is the role of the lateral pterygoid muscle of mastication
- Depression and protrusions
- Only muscle involved in depression, most of the depression is by gravity and relaxation of the muscle
what is the role of the medial pterygoid muscle of mastication
muscle mirrors master on the internal aspect
what are the three paired salivary glands
the Parotid gland
the Submandibular gland
the Sublingual gland.
what innervates the parotid salivary gland
innervated by the Glossopharyngeal nerve
where is the parotid salivary gland
enters the mouth at the level of the upper 2nd molar.
- the facial nerve runs through it but does not innervate it - facial nerve runs through the carotid duct
what innervates the sublingual and submandibular glands
facial nerve
where do the sublingual and submandibular glands drain
- Submandibular gland – frenulum of the tongue is the bulge- lump either side of it where is the submandibular gland is
- On the floor of the mouth is where the sublingual empties into the mouth
what is the two groups of muscles that make up the tongue
intrinsic muscles and extrinsic muscles
- they are skeletal muscles, this is covered in a mucous membrane
what innervates the intrinsic and extrinsic parts of the tongue
they both receive their motor nerve supply from the hypoglossal nerve
what does the intrinsic muscle of the tongue do
involved in changing the shape of the tongue
what does the extrinsic muscles of the tongue do
change the position of the tongue
intrinsic is on top of …
of the extrinsic muscle in the tongue
what is the two parts of the tongue decided by
- you have the anterior 2/3 and posterior 1/3
- towards the back of the tongue there is a V shaped line where the taste buds are enlarged
what is the two types of sensory supply to the tongue
they have special sensory nerves that relay taste and general sensory supply this is being able to sense pain temperature and touch (normal sensory supply)
what does the special sensory nerves do in the tongue
- they relay taste
what does the general sensory supply do in the tongue
- they are able to sense pain, temperature and touch
what is the sensory innervation of the anterior2/3 of the tongue
- Anterior 2/3 – special sensory is chorda tympani (facial) and general sensory is lingual nerve (V3 trigeminal nerve )
what is the sensory innervation of the posterior 1/3 of the tongue
- Posterior 1/3 the special and general sensory are glossopharyngeal
what makes up the hard palate
- The hard palate is composed of the maxilla and palatine bones this forms the roof of the mouth
what make sup the soft palate
soft palate is composed of muscles covered by mucous membrane.
where is the soft palate in relation to the hard palate
the soft palate is posterior to the hard palate
what is the function of the soft palate
The soft palate elevates during swallowing to prevent food entering the nasal cavity.
what is the soft palate innervated by
the vagus nerve
describe the parts that make up the soft palate
- The uvula is the part that hangs down in the mouth
- there are two arches called the palatoglossal arch and palatopharyngeal arch on either side
- in-between the two arches there is tissue this is called the palatine tonsil
describe the divisions of the pharynx
- Divided into three parts these are the nasopharynx (top of nasal cavity to the tip of the uvula), oropharynx(tipe of the uvula to the epiglottis) and laryngopharynx (tip of epiglottis to start of larynx)
describe the innervation of the pharynx
from the glosophrayngeal nerve
what does the pharynx do
- Connects the nasal cavity to the oral cavity and to the larynx
describe the wall of the pharynx
- C shaped muscles called the constrictor muscles
- There are 3 – superior, middle and inferior constrictor muscles they are all innervated by the Vagus nerve
- Stylopharngenous - Elevates the pharynx during swallowing and is innervated by the Glossopharyngeal nerve
what are the 3 constrictor muscles innervated by
the vagus nerve
what does the stylopharyngenous nerve do and what is it innervated by
Elevates the pharynx during swallowing and is innervated by the Glossopharyngeal nerve
describe how the gag reflux works
- The gag reflex is a response to touching the posterior pharyngeal wall (sensory) (Glossopharyngeal nerve) and involves a brisk and brief elevation of the soft palate and contraction of pharyngeal muscles (motor) (Vagus nerve).
