12. Head & neck I Flashcards
What is the anterior nasal septum made of?
Nasal/septal cartilage (hyaline cartilage)
What bones constitute the posterior nasal septum?
1) perpendicular plate of ethmoid bone (at the top of which is the cribriform plate)
2) vomer bone
the maxilla and palatine bones also contribute to the posterior nasal septum
Label this diagram
What is the name of the opening of the nostrils?
Nasal recess
What is the name of the back of the nasal cavity?
Nasal Choanae (choanae are the posterior ends of the nasal cavity and are like passages)
From which bone do the superior and middle nasal conchae/turbinates arise?
Ethmoid bone
From which bone does the inferior nasal choncha/turbinate arise?
Maxillary bone
What is the function of the nasal chonchae/turbinates?
To cause the air to flow in a turbulent manner, warming it up and humidifying it as well as trapping any foreign particles that enter nose in order to stop them entering airways.
Nasal chonchae/turbinates are covered in mucus to aid this function.
What is the name of the space between nasal chonchae/turbinates?
Meatus
hence there is a superior, middle and inferior meatus
Label this image
Which paranasal sinus has lots of little air cells?
Ethmoid sinus, consisting of many ethmoidal air cells
What kind of epithelium lines the paranasal sinuses?
Pseudostratified ciliated columnar epithelium
contain mucus-producing goblet cells which moves across the cilia along with trapped foreign particles and pathogens
Which sinus is the most posterior of the paranasal sinuses?
Sphenoid sinus
Label this image
Label this diagram.
What kind of cross-section is it?
Coronal
What exactly is the role of the paransal sinuses?
Previously believed to be involved in resonance of sound, lightening the skull and olfaction however, currently these are not confirmed so, for now, it is believed the paranasal sinuses do not really have an exact function.
Which paranasal sinuses drain into the semilunar hiatus?
Maxillary, Frontal and Anterior ethmoidal air cells
semilunar hiatus is a groove in the middle meatus
How do paranasal sinuses drain?
via channels called infundibula and then out through ostia
Which paranasal sinuses drain into the ethmoidal bulla?
The middle ethmoidal air cells. Ethmoidal bulla is a prominence of the middle meatus
Which paranasal sinuses drain into the superior meatus?
the posterior ethmoidal air cells
which paranasal sinuses drain into the spheno-ethmoidal recess and what is this recess?
The sphenoid sinuses drain into the spheno-ethmoidal recess.
Spheno-ethmoidal recess is a small space superior to the superior chonchae.
What opens into the inferior meatus?
Nasolacrimal duct
Why does the nose start to run when we cry?
Because nasolacrimal duct opens into the inferior meatus
Which paranasal sinuses get their blood supply from a branch of the external carotid artery?
Maxillary sinuses (via the maxillary branch of the external carotid artery)
Which paranasal sinuses get their blood supply via a branch of the internal carotid artery?
Frontal, Ethmoidal and Sphenoid via the ophthalmic artery
What is the maxillary nerve a branch of?
It is the second branch of the trigeminal nerve (CN V).
The maxillary division (V2) gives off alveolar branches which innervate the teeth. Hence why a sinus infection can cause toothache (referred pain)
Why is obstruction of the maxillary sinuses common?
They drain superiorly into the nasal cavity via a vertical/diagonal canal
Hence foreign particles get trapped and can cause infections
When such infections occur they cause inflammation of mucosal layer which gets swollen and blocks the passage
What is endoscopic maxillary sinus surgery/ functional endoscopic sinus surgery?
Surgical removal of the uncinate process which contributes part of the medial wall of the maxillary sinus.
This is done in order to expose the infundibulum and enlarge passage between the nasal cavity and the maxillary sinus
What structure is at the top of the ethmoid bone?
Crista galli (crest)
What is the function of the perpendicular plate of the ethmoid bone?
superior nasal septum
where do the superior and middle nasal chonchae/turbinates come from?
ethmoid bone
Where is the opening of the eustachian tube?
Nasopharynx (C1-C2)
Where is the adenoid/pharyngeal tonsil?
Nasopharynx
Where are the palatine and lingual tonsils located?
Oropharynx (C2-C3)
what are the boundaries of the laryngopharynx?
located at C4-C5/6
Bounded by epiglottis superiorly and inferior portion of the cricoid cartilage inferiorly (C6)
continuous inferiorly with the oesophagus.
Laryngopharynx contains middle and inferior pharyngeal constrictors
Boundaries of oropharynx
soft palate to epiglottis
contains posterior 1/3 of tongue, lingual tonsils, palatine tonsils and superior constrictor muscle
oropharynx is involved in the voluntary and involuntary phases of swallowing
Boundaries of nasopharynx
nasal choanae to soft palate (and C1)
lined in respiratory epithelium, conditions inspired air and propagates it to the larynx
what is the function of the pharyngeal longitudinal muscles?
widen and shorten the pharynx and elevate the larynx during swallowing
elevation of larynx during swallowing is important in order to move the epiglottis and seal the airway
what is the function of the circular constrictor muscles?
Constrict the pharynx in order to transport bolus of food to oesophagus.
Run from the nasopharynx to the esophagus.
What are the laryngeal muscles innervated by?
Mostly vagus nerve (CN X) apart from stylopharyngeus (glossopharyngeal nerve CN IX)
What separates the nasopharynx from the oropharynx?
uvula (at tip of soft palate)
when do we call the laryngeal tonsils โadenoidsโ?
When they are inflammed
What are the three longitudinal pharyngeal muscles?
Palatopharyngeus
Stylopharyngeus
Salpingopharyngeus (innervated โbyโ CN IX the glossopharyngeal nerve)
Other than widening and shortening the pharynx/ elevating larynx during swallowing, what is another function of salpingopharyngeus muscle?
Opens up the eustachian tube to equalise pressure inside the middle ear
Are the muscles of the pharynx voluntary or involuntary?
Involuntary striated muscle serving for deglutition (swallowing)
Which bones are part of the neurocranium?
- Frontal bone
- Sphenoid bone
- Ethmoid bone
- Occipital bone
- Temporal bone
- Parietal bone
What is another name for the eustachian tube?
the pharyngotympanic tube
infections can spread from nasopharynx into the ear
What are the tonsils in the nasopharynx and oropharynx known as collectively?
Waldeyerโs ring of lymphatic tissue
