Nasal Cavity

Question 1

External nose

Answer 1

Varies in shape/size mostly due to nasal cartilage. 2 nostrils, also known as nares.

Question 2

Roof of nose

Answer 2

Contents include: cribiform plate of the ethmoid bone, nasal bones, maxilla, frontal bones, and nasal cartilage

Question 3

Nasal septum

Answer 3

Separates left and right airways of nose/divides the two nostrils. Comprised of the vomer, the perpendicular plate of the ethmoid, and septal cartilage and meets with the palatine and maxillary bones at the bottom.

Question 4

Floor of the Nose

Answer 4

Floor of the nasal cavity forms the roof of the mouth. Comprised of the hard palate, palatine process of the maxilla (point of articulation between maxilla and palatine), and palatine bone. The incisive foramen, greater palatine foramen, and lesser foramen can be found here, along with their contents [Incisive foramen:nasopalatine nerve & sphenopalatine artery, greater palatine foramen: greater palatine nerve, lesser palatine foramen: lesser palatine nerve]

Question 5

Lateral Wall of Nasal Cavity

Answer 5

Comprised of a series of conchae (KUUNNKKAAAA!!!) and meatuses (spaces below each concha). Conchae are long, narrow, curved bones that force air to flow in a regular pattern around an increased surface area of cilia and temperature increased tissue. Conchae of the nasal cavity are the inferior concha (considered a separate bone), the middle concha (part of the ethmoid), and the superior concha (also part of the ethmoid). Meatuses of the nasal cavity are the inferior, middle, and superior meatuses.

Question 6

Arterial Supply to Nasal Cavity

Answer 6

Anterior ethmoidal artery, Posterior ethmoidal artery, Sphenopalatine artery, greater palatine artery, superior labial artery

Question 7

Anterior Ethmoidal Artery

Answer 7

Branches from opthalmic artery to supply anterior and ethmoid air cells, frontal sinus, and anterosuperior aspect of nasal wall

Question 8

Posterior ethmoidal artery

Answer 8

Branches from opthalmic artery; enters posterior ethmoidal canal. Exits into nasal cavity to supply posterior ethmoidal air cells and nasal septum. Anastomoses with sphenopalatine artery.

Question 9

Sphenopalatine artery

Answer 9

Branch of the maxillary artery. Passes through sphenopalatine foramen to enter the nasal cavity. Gives off posterior septal branches which anastomose with anterior ethmoidal, posterior ethmoidal, and palatine arteries.

Question 10

Greater palatine artery

Answer 10

A terminal branch of the maxillary artery. Supplies blood to the hard palate and nasal septum. Enters through the greater palatine foramen. Eventually anastomoses with the sphenopalatine artery in its course to supply the nasal septum

Question 11

Superior labial artery

Answer 11

Runs along upper lip to supply blood to (duh) upper lip. Gives off vessels which ascend to the nose, including a septal branch to give off to the septum. Anastomoses with superior labial artery on the other side.

Question 12

Venous drainage of the nasal cavity

Answer 12

Rich submucousal plexus (pterygoid plexus) drains into sphenopalatinal vein, facial vein, and opthalmic vein

Question 13

Sphenopalatine vein

Answer 13

Drains into the maxillary vein

Question 14

Facial vein

Answer 14

Starts at the nose, receives blood from external palatine, drains into retromandibular vein. Fun fact: Dr. Khan says that it has no valves but recent literature says that this isn’t true.

Question 15

Opthalamic veins

Answer 15

Superior and inferior veins exist. Join pterygoid plexus.

Question 16

Nerves of the nasal cavity

Answer 16

CNI, Nasopalatine, Greater palatine, lesser palatine, ptyergopalatine ganglion,

Question 17

CNI

Answer 17

Olfactory nerve. Provides special sensation (smell) to the olfactory mucosa

Question 18

Nasopalatine Nerve

Answer 18

Branch of the maxillary nerve. Sensory to the nasal septum and anterior part of the hard palate.

Question 19

Greater Palatine Nerve

Answer 19

From the maxillary nerve (branch of CNV). Sensory to Hard palate

Question 20

Lesser Palatine Nerve

Answer 20

From the maxillary nerve (branch of CNV). Sensory to Soft Palate

Question 21

Pterygopalatine ganglion

Answer 21

Parasympathetic ganglion. Branches of the maxillary nerve pass through this ganglion; ptyergoganglionic parasympathetic fibers from CN VII terminate here.

Question 22

Paranasal Sinuses

Answer 22

Air filled chambers that communicate with the nose. Act as resonating chambers for sound quality. Located in the frontal, maxilla, sphenoid, and ethmoid bones. Each have individual openings that allow sinuses to drain into the nasal cavity. Absent in newborns; develop after birth. Fronal sinuses (2), maxillary sinus (1), sphenoid sinuses (2), and ethmoidal air sinuses (many! 3-18).

Question 23

Frontal Sinus

Answer 23

2. Located in the frontal bone. Duct drains into the middle meatus (part of the ethmoid bone)

Question 24

Maxillary sinus

Answer 24

1. Located in the maxilla. Opens at the hiatus semiluminaris of the middle meatus (part of the ethmoid bone). Most commonly infected of the sinuses: opening of the sinus is small and located on the superior part of the sinus, making it difficult for the sinus to drain. When the mucus membrane of the sinus is congested, it blocks the opening.

Question 25

Sphenoid sinus

Answer 25

2. Located in the sphenoid bone. Open in the sphenoethmoidal recess, a region above the superior concha (once again, ethmoid bone) and between the sphenoid and ethmoid.

Question 26

Ethmoid air cells

Answer 26

Located in the ethmoid bone. Honey comb apperance. 3-18 in number. Arranged in three groups: anterior, middle, and posterior. Anterior and middle groups open into the middle meatus (ethmoid bone). Posterior group open into superior meatus (ethmoid bone)