NASAL CAVITY, PARANASAL SINUSES & NASOPHARYNX Flashcards
what are the three functions of respiration
(1) ventilation (breathing)
(2) gas exchange
• Between the air and blood in the lungs
• Between the blood and other tissues of the body
(3) oxygen utilization by the tissues in the energy- liberating reactions
PHYSICAL REQUIREMENTS of RS
- Surfaceforgasexchange
– Located deep within the body to warm, moisten, and cleanse the incoming air - Thin-walled membrane – To facilitate diffusion
- Selectively permeable membrane – To facilitate diffusion
- Moist membrane
– O2 and CO2 can be dissolved in water to facilitate diffusion - Extensive capillary network
- Effective ventilation mechanism
– To constantly replenish the air - The system must function autonomically
– effective monitoring and feedback mechanisms
– be able to function voluntarily for desired increased or decreased rates
what makes up the upper respiratory tract and what is its function
- nose (nasal cavity)
- nasopharynx
these are used in the conduction division
what makes up the lower Respiratory tract and what is its function
- larynx
- trachea
- bronchial tree (to the terminal bronchioles)
- alveolar ducts
- pulmonary alveoli
- alveolar sac
these function as the respiratory division
what is the role of the muscles around the nose
– Act as sphincters or
dilators
– Control the diameter of the nares and adjust air flow
nasal vestibule
the nostrils lead immediately to this, it is lined by skin that has hair follicles
what is the name of the hair that lines the nasal vestibule
vibrissae, these are the first air filters
the septum divides the nose in half… tell ,e about the make up of the medial wall of the nasal cavity
it is made of bone posteriorly…
vomer inferiorly posteriorly
ethmoid posterior superiorly
and cartilage anteriorly
what makes up the roof of the nasal cavity
nasal, frontal, ethmoid and sphenoid bones (this is the olfactory region)
what makes up the floor of the nasal cavity
palatine bones and the maxilla
what makes up the lateral wall of the nasal cavity
superior concha (these are the passages created) middle concha (S+M Are from one projection) inferior concha
these are turbinates that project from the lateral wall to form the meatuses (these are the actual projections, these named respectively but there is an extra superior one called the spheno-ehtmooidal recess)
role of the concha
− increase surface area
− form air channels (the meatuses)
what two things open into the meatuses
Paranasal sinuses and nasolacrimal duct
Foramen caecum (±)
Connection between nasal veins and superior sagittal sinus
Cribriform plate
Olfactory nerve
Sphenopalatine foramen:
– Sphenopalatine artery (of the
maxillary artery)
– Nasopalatine nerve (of the maxillary nerve)
– Superior nasal branches of the maxillary nerve
Small foramina in the lateral wall:
– Inferior nasal branches from the greater palatine nerve (of the maxillary nerve)
Incisive canal: works both ways
– Nasopalatine nerve (passes from the nasal cavity to the oral cavity)
– Terminal end of the greater palatine artery (passes from the oral cavity to the nasal cavity)
What are the different types of sinus
maxillary
ethmoidal
frontal
sphenoid
what are the roles of the paranasal sinuses
they lighten the skull
– The nasal mucous membrane extends into the sinuses
• ciliated and mucus secreting respiratory mucosa
how are the sinus innervated
branches of the trigeminal nerve
why can’t children get an infection of the sinus
as their sinus are not full formed until later on in life
where do the paranasal sinuses drain to
they drain into the nasal cavity
how does the fontal sinus drain
frontonasal duct ethmoidal infundibulum (middle meatus)
how does the maxillary sinus drain
middle meatus
how do the Middle and anterior ethmoid sinuses drain
On Bulla ethmoidalis and ethmoidal infundibulum to the middle meatus
how does the posterior ethmoid sinus drain
superior meatus
how does the sphenoid sinus drain
spheno-ethmoidal recess to the superior meatus
how does the nasolacrimal duct drain
inferior meatus
relationships of the sinuses
– Maxillary sinus and its opening
– Maxillary sinus and roots of the teeth
– Ethmoid sinuses and the orbit
– Roof of the nasal cavity and the anterior cerebral fossa
– Sphenoid sinus and pituitary (hypophysial) fossa and nasal cavity
– The septum and the conchae
ARTERIAL SUPPLY of the NASAL CAVITY
− 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 artery)
there is also anastomoses between the internal and external carotid arteries
ARTERIAL SUPPLY of the SEPTUM
- Sphenopalatine*artery(ofthe maxillary artery)
- Anterior*andposteriorethmoidal artery (of ophthalmic artery)
- Branchesfromthegreater palatine* artery
- Superiorlabial*artery
the overlap of * is known as the “Little’s or Kiesselbach’s Area”on
the septum
- site of epistaxis (nosebleeds)
ARTERIAL SUPPLY of the SINUSES
Frontal sinus: Supra-orbital a., anterior ethmoidal a.
Ethmoid sinuses: Anterior and posterior ethmoidal aa., sphenopalatine a.
Sphenoid sinus: Posterior ethmoidal a.
Maxillary sinus: Infraorbital and
superior alveolar branches of
maxillary a., greater palatine a., facial a.
VENOUS DRAINAGE
Pterygoid plexus of veins in the infratemporal fossa
Facial vein
Superior ophthal-mic vein
cavernous sinus
Emissary vein in the foramen caecum (may allow the spread of infection into the cranial cavity
LYMPH DRAINAGE
LYMPH DRAINAGE
Anteriorly, the nasal cavity drains to the submandibular nodes
Posteriorly, it drains via the retropharyngeal nodes to the upper deep cervical nodes – Jugulodigastric is palpable if inflamed
nasal cavity NERVE SUPPLY (V1 + V2)
Lateral wall of the nasal cavity: supplied by the Ophthalmic (V1) and Maxillary (V2) divisions of the Trigeminal Nerve
Drake Fig. 8.241
V1 nasociliary mainly anterior ethmoidal nerve Nasal branches
V2 Nasal branches, mainly the greater palatine nerve
nasal septum nerve supply
Nasal septum: supplied by the Ophthalmic (V1) and Maxillary (V2) divisions of the Trigeminal Nerve
V1 Anterior ethmoidal Septal branches
V2 mainly nasopalatine nerve
NERVE SUPPLY of the PARANASAL SINUSES
Frontal sinus: - V1 supra-orbital n. Ethmoidal cells: - V1 nasociliary n. Sphenoid sinus: - V1 posterior ethmoidal n. Maxillary sinus: - V2 infra-orbitalmiddle and anterior superior alveolar n. - V2 posterior superior alveolar n.
NASOPHARYNX
Oval-shaped openings between the nasal cavities and the nasopharynx is called the choanae
Nasopharynx extends from the choanae to the level of the soft palate
Serves only as an air passageway between nasal cavity and oropharynx.
CHOANAE
− horizontal plate of thepalatine bone
− medial plate of the pterygoid process
− vomer
On the inferior-lateral wall is the opening of
pharyngotympanic (auditory, Eustachian) tube
Tubal tonsils
around the opening of the pharyngotympanic tube
There is lymphoid (tonsillar) tissue on its roof
pharyngeal tonsil, adenoid
how are the Salpingopharyngeal and Salpingopalatine folds formed
Salpingopharyngeus and Salpingopalatine muscles run between torus tubarius and pharynx and palate, respectively
The recess behind auditory tube is called
Pharyngeal recess (Fossa of Rosenmuller)
− Most common site of craniopharyngioma
A catheter intended for the auditory tube may miss & enter the pharyngeal recess
− If the pharynx is pierced, the catheter could enter the internal carotid artery!
Adenohypophysis (anterior lobe of the pituitary gland) develops from this region (Rathke’s pouch)
