smell - the nasal cavity and the paranasal sinuses

Question 1

the nose

Answer 1

• part of the respiratory tract
• contains the peripheral organ of smell
• consists of: external nose and nasal cavity

Question 2

functions of the nose

Answer 2

• olfaction (smell)
• respiration
• warms, humidifies and filters air
• deals with the secretions of the nasal mucosa, paranasal sinuses and nasolacrimal ducts

Question 3

external nose

Answer 3

root - lies betwen the orbits
-dorsum - extends from root to apex
- apex - tip of nose
- septum - midline partition
ala - forms the wings of the nose
naris - also termed nostril or anterior nasal aperture

Question 4

nasal cavity

Answer 4

• divided into right and left halves by the nasal septum
• extends from nares to choanae
• each half contains: vestibular part, respiratory part, olfactory part

Question 5

vestibular part

Answer 5

area just inside the nostril
covered with:
- keratinised stratified squamous epithelium
- sweat glands
- sebaceous glands
- vibrissae - hairs longer than cilia that trap large particles

vestibular part filters out particulate matter

Question 6

olfactory part

Answer 6

located above the superior nasal concha on lateral wall, adjacent parts of roof and nasal septum

covered with pseudostratified columnar ciliated epithelium containing receptors for smell

Question 7

respiratory part

Answer 7

greatest chunk of nose
- between vestibular and olfactory parts
- pseudostratified columnar ciliated epithelium with goblet cells
- warms, filters and humidifies the air

Question 8

what does the lamina propria of the respiratory part contain

Answer 8

mucous cells - trap particles
serous cells - humidify air and some produce lysozyme
immune cells - form a defence against invading organisms
- many blood vessels - warm the air

Question 9

nasal cavity

Answer 9

located:
- medial to orbits and maxillary sinuses
- superior to oral cavity and palate
- inferior to the anterior cranial fossa
- divided by the nasal septum
- subdivided by the nasal conchae

Question 10

function of conchae

Answer 10

Conchae help slow down the airflow
- Give the air longer time to warm up and longer time to produce mucous

Question 11

nasal skeleton

Answer 11

anterior part - cartilaginous
posterior part - bony

the mucosa is firmly boinded to the underlying perichondrium (cartilaginous) or periosteum (bony)

Question 12

cartilaginous skeletons

Answer 12

consists of :
5 principle cartilages:
- septal cartilage x 1
- lateral nasal cartilage x2
- greater alar cartilage x2

minor cartilages

fatty fibrous tissue that fills the gaps between the cartilages and the bony skeleton

Question 13

bony skeleton

Answer 13

formed from 9 bones
- frontal
- nasal
- maxilla
- sphenoid
- inferior nasal concha
- ethmoid
- lacrima
- palatine
- vomer

Question 14

nasal septum (medial wall)

Answer 14

Divides the nasal cavity into 2 compartments

perpendicular plate of ethmoid bone and vomer

Question 15

roof of the nasal cavity

Answer 15

• frontal bone
• nasal bone
• cribriform plate of ethmoid
• body of sphenoid and sinus

Question 16

floor of the nasal cavity

Answer 16

palatine process of maxilla
horizontal process of palatine bone

Question 17

lateral wall

Answer 17

irregular due to projections of the nasal conchae

swell bodies are located in the lamina propria of the mucosa covering the conchae- The lamina propria swells up enough to reduce airflow through the nostrils

formed by maxilla, lacrimal, ethmoid, palatine, sphenoid, inferior nasal concha

Question 18

function of nasal conchae

Answer 18

nasal concha, any of several thin, scroll-shaped bony elements forming the upper chambers of the nasal cavities. They increase the surface area of these cavities, thus providing for rapid warming and humidification of air as it passes to the lungs

Question 19

lateral wall of nasal cavity - what lies under the cover of each conchae

Answer 19

the corresponding meatus
superior concha - superior meatus
middle concha - middle meatus
inferior conchae- inferior meatus

the sphenoethmoidal recess likes superoposterior to the superior choncha

Question 20

what does the middle meatus present

Answer 20

ethmoid bulla
- a rounded elevation formed by the middle ethmoid sinuses

hiatus semilunaris
- a semicircular groove inferior to the bulla

Question 21

what does the inferior meatus present

Answer 21

the opening of the nasolacrimal duct

Question 22

blood supply to nasal cavity

Answer 22

the nose receives a rich blood supply
-ophthalmic artery - anterior and posterior ethmoidal
- maxillary artery - sphenopalatine and greater palatine
-facial artery - superior labal (septal branch) and lateral nasal

Question 23

Kiesselbach’s area

Answer 23

clinically significant
- lots of blood vessels all anastamosing there
- easy to cause bleeding

Question 24

venous plexus supply

Answer 24

venous plexus -> sphenopalatine, facial and ophthalmic veins

Question 25

innervation of the nasal cavity

Answer 25

general sensation transmitted by branches of the maxillary and ophthalmic divisions of the trigeminal nerve

olfaction via olfactory nerve CN I

Question 26

innervation of the posterioinferior portion

Answer 26

• nasopalatine nerve
• greater palatine nerve

Question 27

innervation of the anterosuperior portion

Answer 27

anterior ethmoidal (CN V1)

Question 28

paranasal sinuses

Answer 28

• modified air spaces
• possible functions; lighten skull, resonance of voice
• lined by pseudostratified columnar ciliated epithelium with goblet cells
• drain into nasal cavity

Question 29

frontal sinus

Answer 29

located in the frontal bone
- drains via the infundibulum into the middle meatus at the anterior end of the hiatus semilunaris
- innervated by supraorbital branch of ophthalmic division of trigeminal nerve

Question 30

sphenoid sinus

Answer 30

located in sphenoid bone inferior to the sella turcica

clinical significance - access to pituitary gland through this sinus for treatment

drains via an opening in the anterior wall of sphenoidal body into sphenoethmoidal recess

innervated by pharyngeal branch of maxillary division of trigeminal nerve

Question 31

ethmoid air cells

Answer 31

3 groups:
posterior, anterior, middle

Question 32

drainage of ethmoid air cells

Answer 32

anterior - middle meatus, on floor of hiatus semilunaris
middle - middle meatus onto ethmoid bulla
posteiror - posterior ethmoidal