The Structure Of The Upper Respiratory Tract

Question 1

The nose

Answer 1

Most superior portion of the respiratory tract

Multiple functions
-Temperature of inspired air (0.25 second contact)
-Humidity (75-80% RH)
-Filter function
-Defence function
-Cilia take inhaled particulates backwards to be swallowed

Question 2

Anterior nares open into the enlarged

Answer 2

Vestibule
-Skin lined
-Stiff hairs

Surface area of nose
-Doubled by turbinates

Question 3

Turbinates create

Answer 3

Superior meatus
-Olfactory epithelium
-Cribriform plate
-Sphenoid sinus

Middle meatus
-Sinus openings

Inferior meatus
-Nasolacrimal duct

Question 4

The paranasal sinuses

Answer 4

Pneumatised areas of the;
-Frontal
-Maxillary
-Ethmoid
-Sphenoid bones

Pneumatised: having air filled cavity

Arranged in pairs

Evagination of mucous membrane from the nasal cavity

Allow conditioning of air and vacating (sinuses and vocal cords combines allow us to talk)

Question 5

Frontal sinuses

Answer 5

Within frontal lobe

Midline septum

Over orbit and across superciliary arch

Nerve supply- ophthalmic division of V nerve

Question 6

Maxillary sinuses

Answer 6

Located within the body of the maxilla

Pyramidal shape

Base – lateral wall of the nose

Apex – zygomatic process of the maxilla

Roof – floor of the orbit

Floor – alveolar process

Open into the middle meatus

Hiatus semilunaris

Sinuses drain into the gaps of the turbinates

Question 7

Ethmoid sinuses

Answer 7

Between the eyes

Labyrinth of air cells

Semilunar hiatus of the middle meatus (areas created by the turbinates)

Nerve supply- ophthalmic and maxillary V nerve

Question 8

Sphenoid sinuses

Answer 8

Medial to the cavernous sinus
-carotid artery, III, IV, V, VI

Inferior to optic canal, dura and pituitary gland

Empties into sphenoethmoidal recess, lateral to the attachment of the nasal septum

Nerve supply-ophthalmic V

Question 9

Pharynx (won’t be asked)

Answer 9

Fibromuscular tube lined with epithelium

Squamous and columnar ciliated, mucous glands

Skull base —> C6 —> Oesophagus

Anterior —> Nasal Cavities, mouth and larynx
-Nasopharynx
-Oropharynx
-Laryngopharynx (hypopharynx)

Question 10

Nasopharynx

Answer 10

Bounded by
-base of skull
-Sphenoid rostrum
-C Spine
-Posterior to the nose (choana)
-Inferiorly is the soft palate opens to
-oropharynx

Opening of Eustachian tube orifices (lateral wall)
-Supply air to middle ear

Pharyngeal tonsils on posterior wall

Question 11

Oropharynx

Answer 11

Soft palate anteriorly

Palatine tonsils on the lateral walls
-Palatoglossal folds
-Palatopharyngeal folds

Inferiorly is the hyoid bone

Question 12

Larynx (important- comes up in questions)

Answer 12

Sophisticated valve- Valvular function
-Prevents liquids and food from entering lung

Rigid structure

9 cartilages

Multiple muscles

Arytenoid cartilages rotate on the cricoid cartilage to change vocal cords

Question 13

Laryngeal cartilages

Answer 13

9 cartilages:

Single
-Epiglottis
-Thyroid
-Cricoid

Double
-Cuneiform
-Corniculate
-Arytenoid

Question 14

Laryngeal innervation

Answer 14

The vagus (X)
-Superior laryngeal nerve
-Recurrent laryngeal nerve

Laryngeal innervation is supplied by Superior laryngeal nerve
-Inferior ganglion
-Lateral pharyngeal wall
-Divides into
-Internal
Sensation
-External
Cricothyroid muscle

Question 15

Laryngeal innervation (common exam question)

Answer 15

Recurrent laryngeal nerve

All muscles except cricothyroid
-R and L different

Left
lateral to arch of aorta, loops under aorta, ascends between trachea and oesophagus

Right
R Subclavian artery, plane between trachea and oesophagus