Oral Cavity Flashcards
What does mucosa in the upper part of the nasal cavity contain
Olfactory receptors
What forms the nasal septum
Superior posterior septum - perpendicular plate of the ethmoid bone
Inferior posterior septum - vomer
Anteriorly - cartilage
What are the three projections on the lateral surface of the nasal cavity
Superior, middle, inferior conchae
What are the spaces between conchae
Meatus
What separates the nasal cavity from the cranium and brain
Cribriform plate
Perforated with tiny holes - like a sleeve - axons of olfactory nerves pass through these
Where are olfactory receptors located
Spheno-ethmoidal recess in upper nasal cavity - between superior concha and cribriform plate
Where is the frontal sinus
Lies within the anterior part of the frontal bone
Where is the ethmoidal sinus
Ethmoid air cells lie within the ethmoid bone
Where is the sphenoid sinuses
Lie within the sphenoid bone
Where is the maxillary sinuses
Lie within the maxillae of the facial skeleton
What does the frontal sinus drain into
Middle meatus
What does the sphenoid sinus drain into
Spheno-ethmoidal recess
What does the ethmoid air cells drain into
Superior and middle meatus
What does the maxillary sinus drain into
Middle meatus
Where and what is the nasolacriminal duct
Drains fluid that lubricates the anterior surface of the eye
Opens into the inferior meatus
What is the role of the auditory tube
Connects the muddle ear and nasopharynx
Allows air to pass into the middle ear so that the pressure on either side of tympanic membrane is equal
Important for optimal conduction of soundwaves
What is the arterial supply of the nasal cavity
Maxillary artery
What is sensory innervation to the nose
Trigeminal nerve
What is the arterial supply of the nasal septum
Anastomotic network formed by maxillary artery
Often site of bleeding - epistaxis
What is the palate composed of
Hard palate - bone
Soft palate - muscle
What is the hard palate made of
Palatine bone of the maxilla
Horizontal bone of the palatine bone
What is the function of the hard palate
Prevents food or fluid from entering the nasal cavity
Push tongue against it in phase 1 of swallowing
Push tongue against it to articulate certain sounds
What is the midline conical projection in the soft palate
Uvula
What is the role of the soft palate
Contract during swallowing which elevates the soft palate
Nasopharynx is closed off from the oral cavity - preventing reflux of food and fluid into the nasal cavity
What is the soft palate innervated by
Vagus nerve
What are the boundaries of the oral cavity
superiorly - hard and soft palate
Inferiorly - soft tissue and muscles
Laterally - cheeks
What muscles do the cheeks contain
Buccinator muscle
How many teeth do adults have - what are the divisions
32 teeth
16 embedded in the maxilla (upper jaw)
16 embedded in the mandible
4 incisors
2 canines
4 premolars
6 molars
What are teeth composed of
An inner pulp which contains blood vessels and nerves
Dentin which surround pulp
An outer, hard coating of enamel
What does the surface of the tongue bear
Papillae on the superior surface - some of which detect taste
What is the space between the posterior tongue and anterior aspect of the epiglottis
Vallecula
What is the action of the intrinsic muscles of the tongue
Lie entirely within the tongue
Paired bilaterally and fuse in the midline
Change the shape of the tongue
What is the action of the extrinsic muscles of the tongue
Attached to the tongue but originate from outside it - from mandible and hyoid bone
Move the tongue
Name the tonsils
Pharyngeal tonsils
Tubal tonsil
Palatine tonsils
Lingual tonsils
Where are the pharyngeal tonsils
Lies in the roof and posterior wall of the nasopharynx
Where are the tubal tonsils
Surrounds the openings of the auditory tube on the lateral wall of the nasopharynx
Where are the palatine tonsils
Lies on the lateral wall of the oropharynx
Visible
Where are the lingual tonsils
Collection of lymphoid tissue on posterior tongue
What are the stages of swallowing
Oral phase (1)
Pharyngeal phase (2)
Oesophageal phase (3)
Describe the oral phase (1)
Voluntary
Bolus moves from oral cavity into oropharynx
Describe pharyngeal phase (2)
Involuntary
Bolus moves from the oropharynx into the oesophagus
Describe the oesophageal phase (3)
Involuntary
Bolus moves through the oesophagus and into the stomach
What are the muscles involved in the pharyngeal phase (2)
Tongue is blocking the oral cavity
Nasopharynx is sealed off from the oropharynx and laryngopharynx by elevation of the soft palate and its uvula
Larynx elevated due to - suprahyoid muscles and longitudinal pharyngeal muscles = epiglottis blocks the trachea
What are the muscles involved in the oesophageal phase (3)
Food bolus is forced inferiorly from the pharynx into the oesophagus after the contraction of three pharyngeal muscles
- superior, middle, inferior constrictor muscles
Describe the gag reflex
When glossopharyngeal nerve stimulated
Reflex arc leads to contraction of the pharyngeal musculature and elevation of the soft palate
Efferent nerve vagus
What is the purpose of the gag reflex
Protective function against foreign bodies touching the posterior aspect of the oral cavity
What nerve stimulates the gag reflex
Glossopharyngeal
