Nasal cavity, Paranasal Sinuses and Nasopharynx Flashcards
What are the 3 functions of respiration?
- Ventilation (breathing)
- Gas exchange
- between the air and the blood in the lungs
- Between the blood and the tissues
• Oxygen utilisation by the tissues in the energy liberating reactions
What are the functions of the respiratory system?
- Warm, humidify and filter warm air
- Olfaction
- Help produce sound - resonating chamber
- Provide O2 and remove CO2 (main function)
- Acid base balance
- Protective and reflexive non-breathing air movements
- Assist the circulation of the blood and lymph towards the heart (generating negative pressure in the thorax)
- Assist the abdominal muscles during defecation, parturition, lifting a heavy object (increasing intra-abdominal pressure)
Upper respiratory tract
- Nose
- Nasopharynx
Lower respiratory tract
- Larynx
- Trachea
- Bronchial tree
- Alveolar ducts
- Pulmonary alveoli
- Alveolar sac
Conducting division
- Nose
- Nasopharynx
- Larynx
- Trachea
- Bronchial tree to terminal bronchioles
Respiratory division
- Alveolar ducts
- Pulmonary alveoli
- Alveolar sac
Name of the anterior opening of the nose
• Nares/nostrils
What is the role of the muscles around the nostrils?
- Act as sphincters or dilators
- Control the diameter of then are to adjust air flow
What do the nostrils lead in to?
The nasal vestibule
What is the nasal vestibule lined by?
Skin that has hair follicles (vibrissae) that act as the first air filters
What is the blue arrow?
Procerus
What is the green arrow?
Levator labii superioris alaeque nasi
What is the red arrow?
Nasalis
What is the septum made up of?
- Bone posteriorly: vomer and ethmoid
- Cartilage anteriorly
What is the blue?
Cartilage
What is the green?
Vomer
What is the purple?
Ethmoid
What makes up the roof of the nasal cavity?
- Nasal bone
- Frontal bone
- Ethmoid bone
- Sphenoid bone
What region is on the roof of the nasal cavity?
• Olfactory region
What makes up the floor of the nasal cavity?
- Palatine bone
- Maxilla
What does the floor separate?
The nasal and oral cavity
Describe the relevance of the hard palate and insertion of a nasogastric tube
It is horizontal, the tube should be inserted horizontally, when it touches the pharyngeal wall it causes a gag reflex which will cause swallowing
What is the difference between conchae and turbinates?
Concha= bone
Turbinate = bone and mucosal membrane
What is the role of the conchae?
- Increase the surface area
- Form air channels + laminar flow
What opens into the meatuses?
Paranasal sinuses and nasolacrimal duct
Sniffing
Air flow is turbulent
What is the Blue arrow, what is its role?
Foramen caecum
• Connection between the nasal veins and superior sagittal sinus (a kind of vein in the cranial fossa)
What is the green arrow pointing to and what is its role?
- Cribriform plate (perforated ethmoid bone)
- Olfactory nerve passes through
What is the Red arrow pointing to and what is its role?
Sphenopalatine foramen
- Sphenopalatine artery (of the maxillary artery) and
- Nasopalatine nerve (of the maxillary nerve) and
- the superior branches of the maxillary nerve
What is the red line in the hard palate and what is its role?
Incisive canal
- Nasopalatine nerve passes from the nasal to the oral cavity via it
- Terminal end of the greater palatine artery passes from the oral to the nasal cavity
What are the paranasal sinuses lined by?
Nasal mucous membranes (ciliated and mucous secreting respiratory mucosa)
What is the function of the paranasal sinuses?
Lighten the skull (also act as resonating chambers)
What is the innervation of the paranasal sinuses?
Trigeminal nerve
What are the paranasal sinuses?
- Frontal
- Ethmoid cells
- Sphenoidal sinuses
- Maxillary sinuses
What does the frontal sinus drain to?
Ethmoidal infundibulum (middle meatus)
What does the maxillary sinus drain to?
Middle meatus
What does the middle and anterior ethmoid sinuses drain to?
On bulla ethmoidal infundibulum to the middle meatus
What does the posterior ethmoidal sinus drain to?
Superior meatus
What does the sphenoid sinus drain to?
- Spheno-Ethmoidal recess
- Superior meatus
What does the nasolacrimal duct drain to?
Inferior meatus
What is the connection of the nasolacrimal duct?
Between the lacrimal sac and nasal cavity (which is why you get a runny nose when you cry)
Why are infections of the maxillary sinus hard to treat?
The opening of the maxillary sinus is high on the medial wall and relies on the action of the cilia to move fluid out, likely some fluid will remain
What is the sphenoid sinus closely related to and what is this relevant for?
The pituitary fossa
• Transphenoidal surgery
What arteries are the nasal cavity supplied by?
- Terminal branches of the maxillary and facial arteries (branches of the external carotid artery)
- Ethmoidal branches of the ophthalmic artery (branches of the internal carotid)
What is the red arrow
Sphenopalatine artery (of the maxillary artery)
What is the green arrow
Superior labial artery
What is the blue arrow
Anterior ethmoidal artery (of the ophthalmic artery)
What is the black arrow
Greater palatine artery
What is littles area?
- Site of anastomosis between the sphenopalatine, superior labial, anterior ethmoidal and greater palatine arteries
- Site for epistaxis (nosebleed)
Whats the arterial supply of the Frontal sinus?
Supra orbital artery, anterior ethmoidal artery
What is the arterial supply of the ethmoid sinuses?
- Anterior and posterior ethmoidal artery
- Sphenopalatine artery
What is the arterial supply of the sphenoid sinus?
Posterior ethmoidal artery
What is the arterial supply of the maxillary sinus?
- Infraorbital and superior alveolar branches of maxillary artery
- Greater palatine artery
- Facial artery
Where is the pterygoid plexus?
Infra-temporal fossa
Where does the superior ophthalmic vein drain to?
Cavernous sinus
Where is the emissary vein?
Foramen caecum
What is significant about the emissary vein
May allow the spread of infection to the cranial cavity
Anterior lymph Drainage
Submandibular nodes
Posterior drainge of the lymph nodes
Upper cervical nodes via the retropharyngeal nodes
What is the innervation of the lateral wall of the nasal cavity?
Supplied by the opthalmic (V1) and maxillary (V2) divisons of the trigeminal nerve
- V1 -> nasociliary ->mainl anterior ethmoidal nerve -> nasal branches
- V2 -> Nasal branches -> mainly the greater palatine nerve
What is the innervation of the nasal septum?
Supplied by the opthalmic (V1) and maxillary (v2) divisons of the trigeminal nerve
- V1 -> anterior ethmoidal -> septal branches
- V2 -> mainly nasopalatine nerve
What is the red arrow
Anterior ethmoidal nerve
What is the black arrow and what is special about these nerves?
Olfactory nerves - they are capable of regeneration
What is the blue arrow?
Greater palatine nerve
What is the red arrow?
Anterior ethmoidal -> septal branches
What is the blue arrow?
Nasopalatine nerve
What is the innervation of the frontal sinus?
V1 -> Supraorbital nerve
What is the innervation to the Ethmoidal cells?
V1 -> nasociliary nerve
What is the innervation of the sphenoid sinus?
V1 -> Posterior ethmoidal nerve
What is the innervation of the maxillary sinus?
- V2 -> Infra-oribital -> Middle and anterior superior alveolar nerve
- V2 -> Posterior superior alveolar nerve
What are the boundaries of the nasopharynx?
From the chonae to the level of the soft palate
What is the function of the nasopharynx?
Serves as an air passageway between the nasal cavity and oropharynx
What is the chonae?
- The oval shaped opening between the nasal cavities and the nasopharynx
- Rigid
- Horizontal plate of the palatine bone
- Medial plate od the pterygoid process
- Vomer
- Always open
What is the pharyngotympanic tube?
- Infero-lateral wall
- Connects the nasopharynx into the middle ear cavity
- Adjusts the pressure in the middle ear
- Some cartilage to prevent closure (around this cartilage is lymphoid tissue)
Where are the tubal tonsils?
Around the opening of the pharyngotympanic tube
What is the pharyngeal tonsil?
Lymphoid tissue on the roof of the nasal cavity (adenoid)
What is the blue arrow pointing to?
Torus tubaris (maks the end of the catilaginous part of the pharyngotympanic tube)
What are the black arrows pointing to?
- Salpingopalatine fold (anterior)
- Salpingopharyngeus fold (posterior)
What do the salpingopalatine and salpingopharyngeus muscle run between?
- Torus tubaris
- pharynx
- Palate
What is the recess behind the auditory tube?
Pharyngeal recess (Fossa of Rosenmuller)
Pharyngeal recess and its significance to surgery
Most common site of craniopharyngioma
- a catheter intended for the auditory tube may miss and enter the pharyngeal recess
- If the pharynx is pierced, it could enter the internal carotid artery
What is the black arrow pointing to?
Pharyngeal tonsil (one)
What is the blue arrow pointing to?
Tubual tonsil (two)
What is the red arrow pointing to?
Palatine tonsils (2)
What is the green arrow pointing to?
Lingual tonsil (one)
Adenoid face
Untreated inflammation and swelling of the pharyngeal tonsil which obstructs the airway leading to mouth breathing
- Wake up with a dry mouth
- Snoring at an early age
What may happen if there is swelling of the tubal tonsil?
They may obstruct the pharyngotympanic tube and cause middle ear infections which could cause deafness
What are the consequences of a deviated septum?
- Difficulty breathing through the nose
- Nasal congestion
- Frequent sinus infection
- Frequent nose bleeds
What is the main cause of a deviated septum?
Trauma to the nose
