Anatomy of the upper respiratory tract
The respiratory tract consists of upper and lower respiratory tract.
1. Conducting portion: transports air
a. Nose
b. Nasal cavity
c. Pharynx
d. Larynx
e. Trachea
f. Bronchi to bronchioles
2. Respiratory portion: carry out gas exchanges
a. Respiratory bronchioles
b. Alveolar ducts
c. alveoli
The structure of the nasal cavity
1. The roof: ethmoid bone [consists of superior concha and middle concha]
2. The floor: maxilla and palatine bone
o Consists of hard and soft part
The nerves of nasal cavity consists of olfactory epithelium and respiratory epithelium
1. Olfactory epithelium consists:
a. Olfactory receptors - receive the sensation of smell and transmit to olfactory valve
b. Supporting cells
c. Basal cells
2. Respiratory epithelium
a. Pseudostratified ciliated columnar epithelium rich with mucous and serous secreting
cells
The paranasal sinuses
1.
Sphenoidal sinus opens to sphenoethmoidal recess
Frontal sinus opens to the middle meatus
2. Ethmoidal sinus
a.
Anterior and middle part drains into middle meatus
Posterior drains into superior meatus
3.
Maxillary sinus opens to middle meatus
Nose
• External portion supported by the bone and cartilage
• Interior divided by midline nasal septum into halves
• Roof contains olfactory epithelium
• Lined by the respiratory epithelium
• Surrounded by paranasal sinuses
,Functions:
• Filtration of dust
• humidification of inspired air
• Sense of smell
• Paranasal sinuses lighten skull and function same as nasal cavity
Clinical importance
1. Sinusitis- inflammation of paranasal sinus
2. Maxillary sinusitis- by sensation of toothache (upper molar teeth)
3. Epistaxis- little's area (the inferior part of the nasal septum) bleeding of the nose
Pharynx consists of 3 subdivisions:
A. Nasopharynx- nasal cavity to larynx
B. Oropharynx - oral cavity to esophagus
C. Laryngopharynx - superior border of epiglottis to inferior border of cricoid cartilage
Tonsils
1. Pharyngeal
2. Tubal
3. Palatine
4. Lingual
Functions
• Passage for air and food
• Tonsils respond to the inhale antigens
Clinical Importance
1. Dysphagia- difficulty in swallowing
2. Chocking of food- laryngeal obstruction
3. Waldeyer's ring- ring of lymphoid tissue formed by: ***
a. Palatine tonsils (laterally)
b. Pharyngeal tonsils (above and posteriorly)
c. Lingual tonsils (below and anteriorly)
4. Tonsillitis- infection of the tonsils
5. Tonsillectomy- removal of tonsils from its bed
Larynx
• Framework of cartilages and dense connective tissue membranes
• Located in the anterior neck at the level of CV3 to CV6 then trachea starts at CV7
•
Beginning of larynx- epiglottis
End of larynx- cricoid cartilage
• Thyroid cartilages- "adam's apple"
Functions:
1. Guard the air passages
2. Prevents food from entering into the respiratory tract
3. Voice production
,Four cartilages:
i. Corniculate cartilage
ii. Thyroid cartilage
iii. Arytenoid cartilage
iv. Cricoid cartilage
Rima glottidis- space between the vocal folds [allow the air to diffuse in]
The laryngeal cavity **** (must understand) - check the MCQ questions
• Cricothyroid muscle (only intrinsic laryngeal muscle innervated by external
laryngeal[superior laryngeal nerve])
1. Cricothyroid muscle increases the tension on vocal ligament (raise pitch)
2. Adduction by lateral cricoarytenoid (phonation)
3. Adduction by trans/ oblique arytenoids mm. (phonation)
4. Slackening by vocalis and thyroarytenoid mm. (lower pitch)
*1,2,3,4 make sound
1. Abduction by posterior cricoarytenoid muscle (only abductor)
2. Adduction by lateral cricoarytenoid (phonation)
3. Adduction by trans/ oblique arytenoids mm. (phonation)
4. Slackening by vocalis and thyroarytenoid mm. (lower pitch)
*1,2,3,4 innervated by recurrent laryngeal [inferior laryngeal nerve]
Clinical Importance
1. Laryngoscopy
2. Superior and recurrent laryngeal nerves injury during thyroid operation
3. Cricothyroid muscle tense the vocal ligament.
• Results in easily fatigued voice with poor pitch control
4. Left recurrent laryngeal nerve is in the superior mediastinum and can be injured or trapped
by tumor
• Weakness or paralysis of all intrinsic laryngeal muscle
• Except the cricothyroid muscle as it is innervated by external laryngeal muscle
, Sore Throats
1. Pharyngitis: pain and inflammation of the pharynx
2. Tonsillitis: inflammation of the tonsils
3. Laryngitis: inflammation of the larynx
a. Hoarseness and reduced vocal pitch [mainly caused by virus]
4. Epiglottitis: inflammation of the epiglottis (medical emergency)
a. Acute epiglottitis- acute, rapidly progressively cellulitis of the epiglottis and
adjacent structures that can result in complete and potentially fatal- airway
obstruction in both children and adults
b. Generally due to H.influenzae capsular type b bacteria
c. Cause difficulty in breathing
d. Prevention: vaccination with HiB vaccine
Pharyngitis
• Acute pharyngitis is an inflammation of the pharynx and tonsils
• Common cause of bacterial pharyngitis: streptococcus pyogenes
• Etiology:
o Viral （40-60%）
o Bacterial （5-40%）
o Fungal
o environmental
Viral Pharyngitis
1. Adenovirus
a. Double stranded DNA
b. Icosahedral with 70-90nm
c. Symptoms:
i. Cough
ii. Runny nose
iii. White bumps on the tonsils and throat
iv. Mild diarrhea
v. Vomiting and rash
d. Detection:
i. Virus isolation in cell culture form throat swabs
ii. Detect antigen in nasopharyngeal aspirates by immunofluorescence
iii. DNA detection using PCR
iv. Serology
v. Can be isolated from feces and urine ***
2. Coxsackievirus
a. Non enveloped virus with linear ssRNA
b. Divided into group A and B viruses based on early observations of their
pathogenicity in mice
c. Group A- infect the skin and mucous membranes
i. Cause herpangina
ii. Acute hemorrhagic conjunctivitis
iii. Hand- foot and mouth disease
d. Detection:
i. Virus isolation in cell culture (cytopathic effect can be seen within 2-6 days)
The respiratory tract consists of upper and lower respiratory tract.
1. Conducting portion: transports air
a. Nose
b. Nasal cavity
c. Pharynx
d. Larynx
e. Trachea
f. Bronchi to bronchioles
2. Respiratory portion: carry out gas exchanges
a. Respiratory bronchioles
b. Alveolar ducts
c. alveoli
The structure of the nasal cavity
1. The roof: ethmoid bone [consists of superior concha and middle concha]
2. The floor: maxilla and palatine bone
o Consists of hard and soft part
The nerves of nasal cavity consists of olfactory epithelium and respiratory epithelium
1. Olfactory epithelium consists:
a. Olfactory receptors - receive the sensation of smell and transmit to olfactory valve
b. Supporting cells
c. Basal cells
2. Respiratory epithelium
a. Pseudostratified ciliated columnar epithelium rich with mucous and serous secreting
cells
The paranasal sinuses
1.
Sphenoidal sinus opens to sphenoethmoidal recess
Frontal sinus opens to the middle meatus
2. Ethmoidal sinus
a.
Anterior and middle part drains into middle meatus
Posterior drains into superior meatus
3.
Maxillary sinus opens to middle meatus
Nose
• External portion supported by the bone and cartilage
• Interior divided by midline nasal septum into halves
• Roof contains olfactory epithelium
• Lined by the respiratory epithelium
• Surrounded by paranasal sinuses
,Functions:
• Filtration of dust
• humidification of inspired air
• Sense of smell
• Paranasal sinuses lighten skull and function same as nasal cavity
Clinical importance
1. Sinusitis- inflammation of paranasal sinus
2. Maxillary sinusitis- by sensation of toothache (upper molar teeth)
3. Epistaxis- little's area (the inferior part of the nasal septum) bleeding of the nose
Pharynx consists of 3 subdivisions:
A. Nasopharynx- nasal cavity to larynx
B. Oropharynx - oral cavity to esophagus
C. Laryngopharynx - superior border of epiglottis to inferior border of cricoid cartilage
Tonsils
1. Pharyngeal
2. Tubal
3. Palatine
4. Lingual
Functions
• Passage for air and food
• Tonsils respond to the inhale antigens
Clinical Importance
1. Dysphagia- difficulty in swallowing
2. Chocking of food- laryngeal obstruction
3. Waldeyer's ring- ring of lymphoid tissue formed by: ***
a. Palatine tonsils (laterally)
b. Pharyngeal tonsils (above and posteriorly)
c. Lingual tonsils (below and anteriorly)
4. Tonsillitis- infection of the tonsils
5. Tonsillectomy- removal of tonsils from its bed
Larynx
• Framework of cartilages and dense connective tissue membranes
• Located in the anterior neck at the level of CV3 to CV6 then trachea starts at CV7
•
Beginning of larynx- epiglottis
End of larynx- cricoid cartilage
• Thyroid cartilages- "adam's apple"
Functions:
1. Guard the air passages
2. Prevents food from entering into the respiratory tract
3. Voice production
,Four cartilages:
i. Corniculate cartilage
ii. Thyroid cartilage
iii. Arytenoid cartilage
iv. Cricoid cartilage
Rima glottidis- space between the vocal folds [allow the air to diffuse in]
The laryngeal cavity **** (must understand) - check the MCQ questions
• Cricothyroid muscle (only intrinsic laryngeal muscle innervated by external
laryngeal[superior laryngeal nerve])
1. Cricothyroid muscle increases the tension on vocal ligament (raise pitch)
2. Adduction by lateral cricoarytenoid (phonation)
3. Adduction by trans/ oblique arytenoids mm. (phonation)
4. Slackening by vocalis and thyroarytenoid mm. (lower pitch)
*1,2,3,4 make sound
1. Abduction by posterior cricoarytenoid muscle (only abductor)
2. Adduction by lateral cricoarytenoid (phonation)
3. Adduction by trans/ oblique arytenoids mm. (phonation)
4. Slackening by vocalis and thyroarytenoid mm. (lower pitch)
*1,2,3,4 innervated by recurrent laryngeal [inferior laryngeal nerve]
Clinical Importance
1. Laryngoscopy
2. Superior and recurrent laryngeal nerves injury during thyroid operation
3. Cricothyroid muscle tense the vocal ligament.
• Results in easily fatigued voice with poor pitch control
4. Left recurrent laryngeal nerve is in the superior mediastinum and can be injured or trapped
by tumor
• Weakness or paralysis of all intrinsic laryngeal muscle
• Except the cricothyroid muscle as it is innervated by external laryngeal muscle
, Sore Throats
1. Pharyngitis: pain and inflammation of the pharynx
2. Tonsillitis: inflammation of the tonsils
3. Laryngitis: inflammation of the larynx
a. Hoarseness and reduced vocal pitch [mainly caused by virus]
4. Epiglottitis: inflammation of the epiglottis (medical emergency)
a. Acute epiglottitis- acute, rapidly progressively cellulitis of the epiglottis and
adjacent structures that can result in complete and potentially fatal- airway
obstruction in both children and adults
b. Generally due to H.influenzae capsular type b bacteria
c. Cause difficulty in breathing
d. Prevention: vaccination with HiB vaccine
Pharyngitis
• Acute pharyngitis is an inflammation of the pharynx and tonsils
• Common cause of bacterial pharyngitis: streptococcus pyogenes
• Etiology:
o Viral （40-60%）
o Bacterial （5-40%）
o Fungal
o environmental
Viral Pharyngitis
1. Adenovirus
a. Double stranded DNA
b. Icosahedral with 70-90nm
c. Symptoms:
i. Cough
ii. Runny nose
iii. White bumps on the tonsils and throat
iv. Mild diarrhea
v. Vomiting and rash
d. Detection:
i. Virus isolation in cell culture form throat swabs
ii. Detect antigen in nasopharyngeal aspirates by immunofluorescence
iii. DNA detection using PCR
iv. Serology
v. Can be isolated from feces and urine ***
2. Coxsackievirus
a. Non enveloped virus with linear ssRNA
b. Divided into group A and B viruses based on early observations of their
pathogenicity in mice
c. Group A- infect the skin and mucous membranes
i. Cause herpangina
ii. Acute hemorrhagic conjunctivitis
iii. Hand- foot and mouth disease
d. Detection:
i. Virus isolation in cell culture (cytopathic effect can be seen within 2-6 days)
