Nasal cavity, paranasal sinuses, nasopharynx

complete

What is ventilation?

breathing - moving gas to site of exchange

where does gas exchange occur?

capillary beds at lungs and tissues

what are the functions of the respiratory system?

• primarily gas exchange

• pH balance

• speech/vocalisation

• protection and maintenance of lungs and rest of body

what are other metabolic functions of the respiratory system?

• angiotensin 1 to angiotensin 2

• prostaglandin synthesis

what structures are in the conducting portion of the respiratory system?

• nose, nasal cavity and paranasal sinuses

• pharynx

• larynx

• trachea

• bronchi, bronchial tree

• terminal bronchioles

what structures are in the respiratory portion of the respiratory system?

• respiratory bronchioles

• alveoli (ducts and sacs)

how many alveoli are there per lung?

400 million

what is the nose made up of?

cartilage, muscle, soft tissue, nasal bone

what is another word for nostrils?

nares

what cartilages are found in the nose?

• septal cartilage

• major alar cartilage

• minor alar cartilages

what muscle acts to flare the nostrils?

nasalis

what is nasalis innervated by?

facial nerve (CN VII)

what space occurs after passing nostrils?

nasal vestibule

what epithelium is found in the nasal vestibule?

squamous

what is another word for nasal hair and what effect does it have?

vibrissae and it has a filtering effect

what organism is associated with nasal vestibulitis?

S. aureus

what is the bony structure of the nasal cavity covered by?

respiratory mucosa - respiratory epithelium

what is the floor of the nasal cavity made up of?

hard and soft palate

what bones make up the lateral wall of the nasal cavity?

• ethmoid (superior and middle conchae)

• inferior nasal concha

• maxilla

• sphenoid

• palatine bone

• lacrimal

• nasal bone

what is the hard palate made up of?

• palatine process of maxilla

• horizontal process of palatine bone

what is the medial wall (septum) of the nasal cavity made up of?

• perpendicular plate of ethmoid

• vomer

• septal cartilage

what type of epithelium is found in the nasal cavity?

• respiratory (mostly)

• olfactory (superiorly)

• NALT (nasal associated lymphoid tissue) (posteriorly)

• squamous mucosa (anteriorly)

what type of epithelium is respiratory mucosa?

cilliated psuedostratified columnar epithelium

what structures are found in respiratory mucosa?

• cilliated psuedostratified columnar epithelium

• goblet cells

• rich vascular supply of submucosal glands

which cranial nerve is the olfactory nerve?

CN 1

what are olfactory tracts?

extensions of the forebrain

where does the olfactory nerve terminate?

the olfactory bulb

what is the pathway from the olfactory mucosa back to the brain?

olfactory mucosa → olfactory neurones → olfactory bulb → olfactory tract → medial and lateral striae → piriform cortices

what do olfactory neurones pass through?

the cribriform plate

what pathways are there into the nasal cavity?

• foramen cecum

• cribriform plate

• sphenopalatine foramen

• lateral wall foramina

• incisive canal

what is the foramen cecum?

a venous connection between nasal veins and a superior sagittal sinus

what passes through the sphenopalatine foramen?

• sphenopalatine artery

• nasopalatine and superior nasal nerves

what passes through the lateral wall foramina?

• posterior inferior nasal branches of greater palatine nerve

what passes through the incisive canal?

• nasopalatine nerve

• greater palatine/sphenopalatine artery

which gateway in the nasal cavity provides a pathway to the oral cavity?

incisive canal

what arteries are the anastomoses between in the nasal cavity?

branches of the internal and external carotid arteries

what do the anterior and posterior ethmoidal arteries arise from?

the ophthalmic artery which arises from the internal carotid

what do the anterior and posterior ethmoidal arteries give off?

lateral and septal branches

what do the anterior and posterior ethmoidal arteries cross?

the cribriform plate

what does the sphenopalatine artery arise from?

Maxillary artery which arises from the external carotid

what does the descending palatine artery arise from?

maxillary artery

what does the facial artery arise from?

maxillary artery

what does the sphenopalatine artery give off?

• posterior lateral nasal

• posterior septal

what does the descending palatine artery give off?

the greater palatine artery

what does the facial artery give off in the nasal cavity?

• super labial artery

• lateral and septal nasal arteries

what is the cavernous sinus joined by?

the superior ophthalmic vein

what is the issue with the venous drainage in the nasal cavity?

there are a lack of valves which can lead to infection spreading to the vein

aside from the superior ophthalmic vein, what else drains the nasal cavity?

the pterygoid plexus ad facial vein

what does the facial vein drain to?

the internal jugular

what does lymph drain to posteriorly in the nasal cavity?

retropharyngeal nodes

what does lymph drain to anteriorly in the nasal cavity?

submandibular nodes

what does the nasal cavity lymph drain to after retropharyngeal and submaibular nodes?

deep cervical lymph nodes

what is the named lymph node in the neck that can be palpated if inflamed?

jugulodigastric node

what are the main cranial nerves that innervate the nasal cavity?

• olfactory (CNI)

• trigeminal (opthalmic, maxillary, mandibular divisions) (CN V1,2,3)

• facial (CN VII)

which part of the nasal cavity is the territory of the ophthalmic nerve?

upper half (diagonal line from nose to ear)

which part of the nasal cavity is the territory of the maxillary nerve?

lower half (diagonal line from nose to ear)

which nerve is special sensory in the nasal cavity?

olfactory nerve

which cranial nerves are somatic sensory in the nasal cavity?

V1 and V2 (ophthalmic and maxillary)

what does the opthalmic division of the trigeminal nerve branch into?

nasicillary nerve → anterior ethmoidal (lateral and septal nasal branches)

what does the maxillary division of the trigeminal nerve branch into?

nasopalatine and greater palatine nerves

what is the autonomic innervation to the nasal cavity?

facial nerve

what is the function of the facial nerve in the nasal cavity?

parasympathetic secretomotor

what is the sympathetic innervation to the nasal cavity via?

periarterial fibres - from the superior cervical ganglion

what is the different name for conchae when they are covered by mucus?

turbinates

what is the significance of the turbinates in the nasal cavity?

increase surface area and aid in warming and humidifying air

what does turbinate flow aid in and what is it called?

aids in the filtering of particles before they reach further into the airway - turbulent precipitation

what are the paranasal sinuses?

• frontal

• sphenoidal

• maxillary

• ethmoidal (anterior, middle and posterior cells)

which paranasal sinus is particularly prone to sinusitis?

maxillary sinus

what do the paranasal sinuses drain into?

the lateral aspect of the nasal cavity

what is the function of paranasal sinuses?

aid in warming and humidifying air

what is the space under a concha called?

meatus

where does the frontal sinus drain to?

the middle meatus through the ethmoidal infundibulum

what drains to the middle meatus?

• frontal sinus

• anterior ethmoidal air cells

• maxillary sinus

where do the middle ethmoidal and posterior ethmoidal air cells drain to?

the ethmoidal bulla in the middle meatus

what does the sphenoidal sinus drain to?

the spheno ethmoidal recess - located posterior and superior to the superior concha

what does the maxillary sinus drain to?

the middle meatus via the semilunar hiatus

what drains to the inferior meatus?

the nasal lacrimal duct (from the lacrimal apparatus of the eye)(runny nose when cry)

what is the growth of nasal cavities from childhood called?

pneumatization

where do paranasal sinuses drain?

to the nasal cavity

what exists below each conchae?

a space called a meatus

what does the frontal sinus drain to?

middle meatus via frontonasal duct and ethmoidal infundibulum

where do anterior ethmoidal cells drain to?

middle meatus via ethmoidal infundibulum

where do middle ethmoidal cells drain to?

middle meatus (ethmoidal cells)

where do posterior ethmoidal cells drain to?

superior meatus

where does the maxillary sinus drain?

middle meatus via semilunar hiatus

where does the sphenoidal sinus drain?

sphene-ethmoidal recess

where does the nasolacrimal duct drain?

the inferior meatus

what are clinical implications that could affect paranasal sinuses?

sinusitis, fractures/trauma, maxillary dentition, pituitary gland tumour

what nerve supplies the frontal sinus?

Supra orbital (CN V1)

what nerves supply the ethmoidal sinus?

• Ant. And post. Ethmoidal (Nasociliary from CN V1)

• Orbital branches CN V2 from pterygopalatine ganglion

what nerves supply the sphenoidal sinus?

• Post. Ethmoidal (Nasociliary from CN V1)

• Orbital branches CN V2 from pterygopalatine ganglion

what nerves supply the maxillary sinus?

Infra orbital and superior alveolar branches maxillary nerve (CN V2)

what artery supplies the frontal sinus?

anterior ethmoidal (ophthalmic)

what arteries supply the ethmoidal sinus?

anterior and posterior ethmoidal (ophthalmic)

what arteries supply the sphenoidal sinus?

pharyngeal arteries (maxillary)

what arteries supply the maxillary sinus?

infraorbital and superior alveolar branches of maxillary artery

what is the first part of the pharynx?

nasopharynx

what does the nasopharynx communicate with the nasal cavity via?

choanae

what does the nasopharynx become below the soft palate?

orthopharynx

what is the sensory innervation to the nasopharynx?

pharyngeal branch of CN V2