Anatomy of the skull Flashcards
What happens to the condyle when the mouth opens?
- moves anteriorly
What are sinuses?
- Air spaces within the bone
Which bones within the skull contain sinuses?
- Maxilla
- Ethmoid
- Frontal
- Sphenoid
What is the Oro-pharyngeal Isthmus?
- the space bound by the palatoglossal and palatopharyngeal arches and the base of the tongue
Where is the lingual frenulum?
- attaches to the ventral surface of the tongue and the floor of the mouth
What is Ankyloglossia?
- shortened frenula
What bones comprise the hard palate?
- Palatine process of the maxilla
- Horizontal plate of the palatine bone
Where is the greater palatine foramen located?
- between the maxilla and the palatine bone
Where is the lesser palatine foramen found?
- in the palatine bone
Where is the incisal foramen found?
- behind the upper incisor teeth
What is the line in the tongue called that divides the anterior 2/3 from the posterior 1/3?
- Sulcus terminalis
What are the islands of the tongue called which cross from the posterior 1/3 into the anterior 2/3?
Circumvallate papillae
Where is the mental foramen located?
- On the buccal surface of the body of the mandible
Where is the Infra–orbital foramen located?
- in the maxilla
Which cranial nerve is the facial nerve?
- number 7
What cranial nerve is the trigeminal nerve?
- number 5
What is the Pterygomandibular Raphe?
Attaches to the buccinator muscle and the superior constrictor
What is the function of the facial nerve?
- The major motor supply to the muscles of facial expression
Where do the branches of the facial nerve pass through?
- The parotid gland
What is Bells Palsy?
- When the muscles of facial expression become paralysed due to a virus inflaming the facial nerve
What is the function of the trigeminal nerve?
- Provide sensory function to the face
What are the branches of the trigeminal nerve?
- Mandibular
- Maxillary
- Opthalmic
What are the branches of the facial nerve called?
- Temporal
- Zygomatic
- Buccal
- Mandibular
- Cervical
What is the muscle that surrounds the lips called?
- Obicularis Oris
What is the muscle that surrounds the eyes called?
- Obicularis Oculi
What is the Dura Mater?
- A protective layer between the skull and the brain
What happens if there is a rupture in the middle meningeal artery?
- blood builds up between the skull and the dura mater, pushing the brain down through the magnum foramen (Extradural Haemorrhage)
Where does the lingual artery originate from>
- The external carotid artery
What does the lingual artery supply?
- The tongue
- The floor of the mouth
What is the main vein called that drains venous blood away from the head and neck?
- Internal jugular vein
What is the pterygoid plexus of veins?
- A lattice of veins at the side of the face
What does the pterygoid plexus of veins do?
- drains blood from many structures in the anterior section of the face
How might infection be brought to the brain through a spot on the face?
- when the spot on the anterior portion of the face is squeezed some of the infection may be forced into the venous blood supply
- this blood is carried to the pterygoid plexus of veins
- The plexus of veins communicates with the cavernous sinus in the brain
What is the function of lymphatic vessels?
- to drain tissue fluid from tissues and back into th venous system
What happens to lymph nodes in response to infection?
They swell
What re the two groups of lymph nodes in the head known as?
- Deep
- Superficial
Where are the superficial lymph nodes found?
- in a ring around the base of the head
What does the greater palatine artery supply?
- palatine gingiva of the upper teeth
- The mucosa of the hard palate
What does the lesser palatine artery supply?
The soft palate
Where does the middle meningeal artery run to?
Runs inside the skull, deep into the pterion
What is the Pterion?
A weakened section of the skull where the bones meet
What are the attachments of the digastric muscle?
- The mastoid process
- The hyoid bone
The mandible
What are the actions of the digastric muscle?
- Assist with the opening of the mouth
- keeps the mouth held closed in an unconscious reflex (stretch reflex)
What nerve supplies the digastric muscle?
The anterior section is supplied by the mandibular branch of the trigeminal nerve
The posterior section is supplied by the facial nerve
What is the action of the TMJ?
Involved in opening and closing the mouth
What is the function of the masseter?
- Plays a major role in chewing
- pulling the mandible upwards
What are the attachments of the masseter?
- The zygomatic bone
- The mandible
What is the nerve supply to the masseter?
The mandibular branch of the trigeminal nerve
What are the attachments of the temporalis?
- temporal fossa and fascia
- coronoid process
What is the action of the temporalis?
- moves the mandible forwards (anterior section)
- moves the mandible backwards (posterior section)
What is the nerve supply to the temporalis?
The mandibular branch of the trigeminal nerve
What are the attachments of the Medial Pterygoid muscle?
- Superficial head attaches to the maxillary tuberosity, the pyramidal process of the palatine bone and the ramus of the mandible
- Deep head - attaches to the lateral pterygoid plate of the sphenoid and the ramus of the mandible
What is the action of the Medial Pterygoid Muscle?
Elevates the mandible (closing the mouth)
What is the nerve supply to the Medial Pterygoid Muscle?
The mandibular branch of the Trigeminal nerve
What are the attachments to the Lateral Pterygoid Muscle?
- Superior head - the greater wing of the sphenoid and the condyle
- Inferior head - the lateral pterygoid plate of the sphenoid and the condyle
What is the action of the Lateral Pterygoid Muscle?
- Push the jaw forwards and side to side
What is the nerve supply of the Lateral Pterygoid Muscle?
The mandibular branch of the trigeminal nerve.
What Is the origin of the Styloglossus muscle?
The styloid process
What is the action of the Styloglossus muscle?
Lifts the tongue up and back
What is the origin of the Hyoglossus muscle?
The Hyoid Bone
What is the action of the Hyoglossus muscle?
Pulls the tongue downwards
What is the origin of the Genioglossus Muscle?
The genial tubercles of the mandible
What is the action of the Genioglossus muscle?
Protrudes the tongue
What is the outer muscle layer of the pharynx?
The outer muscle layer of the pharynx is split into superior, middle and inferior constrictors
What muscles are involved in the inner muscle coat of the pharynx?
- Stylopharyngeus
- Salpingopharyngeus
- Palatopharyngeus
What is the motor nerve supply to the Pharynx?
Cranial nerve 10 (Vagus nerve)
- except the stylopharyngeus which is supplied by the glossopharyngeal nerve