The document discusses various respiratory tract infections that can occur in the upper and lower respiratory system. It provides details on: - Common upper respiratory infections like rhinitis, sinusitis, tonsillitis, pharyngitis, and laryngitis which affect the nose, sinuses, throat, and voice box. - Symptoms, causes (often viral or bacterial), and treatment options for each condition. - Anatomy and physiology of the respiratory system including the nose, pharynx, larynx, trachea, bronchi, lungs, and mechanisms of gas exchange.

1. RESPIRATORY TRACT INFECTIONS

2. RELATED ANATOMY & PHYSIOLOGY
• The respiratory system consists of the nose, pharynx (throat), larynx
(voice box), trachea (windpipe), bronchi and lungs.
• Structurally, the respiratory system consists of two parts:
1. The upper respiratory system includes the nose, pharynx, larynx and
associated structures.
2. The lower respiratory system includes the trachea, bronchi and lungs
• The lower respiratory tract fills most of the Thoracic Cavity

4. CONT..
• Respiratory system functions mainly as gas exchange system for O2
and CO2  cellular respiration (energy production)
• It closely tied to circulatory system
• Functionally the organ of the respiratory system can also be
subdivided into:
1. Conducting division: passages that serve only for airflow
2. Respiratory division: alveoli and gas exchange areas

6. CONT..
1. The conducting zone consists of a series of interconnecting cavities
and tubes both outside and within the lungs.
• These include the nose, nasal cavity, pharynx, larynx, trachea,
bronchi and bronchioles.
• Their function is to filter, warm, and moisten air and conduct it into
the lungs

7. CONT..
2. The respiratory zone consists of tubes and tissues within the lungs
where gas exchange occurs.
• These include the alveolar ducts, alveolar sacs and alveoli. (Gas
exchange occur in these zone)

9. Respiratory mucosa
• It covers most of the nose, pharynx,
larynx, trachea, bronchi and
bronchioles
• It contains mucus producing goblet
cells and ciliated epithelium.
• Mucus can trap contaminants.
• Cilia move them up towards mouth

11. NOSE
• It provides an entrance for air in which air is filtered by hairs inside
the nostrils.
• It has two portions : the external and internal.
• The external portion is supported by a framework of bone and
cartilage covered with skin and lined with mucous membrane.
• The internal portion is a large cavity beneath the skull, merging with
the external nose anteriorly and communicating with the throat
posteriorly.

13. CONT..
• The anterior portion of the nasal cavity just inside the nostrils, called
the nasal vestibule is surrounded by cartilage.
• The superior part of the nasal cavity is surrounded by bone.
• A vertical partition, the nasal septum divides the nasal cavity into right
and left sides.
• The anterior portion of the nasal septum consists primarily of hyaline
cartilage.

15. PARANASAL SINUSES
• Four bones of the skull contain paired air spaces called the paranasal
sinuses - frontal, ethmoidal, sphenoidal, maxillary.
• Add resonance to voice.
• Communicate with the nasal cavity by ducts.
• Lined by pseudostratified ciliated columnar epithelium.

17. PHARYNX (THROAT)
• The pharynx is a funnel-shaped tube about 13 cm
or 5” long that starts at the internal nares and
extends to the junction with esophagus and trachea
• It is a common passage for air and food.
• divided into three regions:
a. Nasopharynx: includes uvula, tonsils (adenoids),
auditory tube
b. Oropharynx: extended from soft palate to level of
hyoid bone
c. Laryngopharynx: from hyoid bone to
esophagus/larynx

19. LARYNX
• Larynx or Voice box is a short, cylindrical airway ends in the trachea.
It is about 5 cm long.
• Opening into larynx = glottis
• Boundaries:
– Superiorly it attaches to hyoid bone and opens into laryngopharynx
– Inferiorly trachea.
– Posteriorly esophagus
• Functions:
- Prevent food from entering lower respiratory system
- Sound, speech, etc.

21. TRACHEA
• Flexible cylindrical tube, Size is 4 – 5 inch long
& 1 inch diameter, also called windpipe.
• Extends from larynx to bronchi
• Surrounded by “C” – shaped bands of cartilage,
ends joined by bands of muscle tissue
• Cartilage provide rigidity to the tracheal wall,
holds walls open, prevents collapse.

22. BRONCHI
• Trachea divides into two branches called bronchi.
• Each bronchus enters lung and continues to divide
into smaller and smaller branches = bronchi, then
= bronchioles
• 2 primary bronchi branches into 5 secondary
bronchi (1 for each lobe of lung)
• Each of these branches into tertiary bronchi
• Bronchioles
- smallest branches of “respiratory tree”
- <1mm diameter
- no supportive cartilage

23. LUNGS
• Lung occupies most of the space within the thoracic cavity.
• Toward the midline, the lungs are separated from each other by the
mediastinum and this is called the mediastinal surface.
• The relatively broad, rounded surface in contact with the thoracic wall
is called the costal surface of the lung.
• The superior end of the lungs narrows to a rounded tip known as the
apex.
• The inferior end of the lungs, known as the base.
• Right lung has 3 lobes and left lung has 2 lobes

25. Pleura and Pleural Cavity
• The outer surface of each lung and the adjacent internal thoracic wall
are lined by two layered serous membrane called pleura.
• The outer surface of each lung is tightly covered by the visceral
pleura.
• while the internal thoracic walls, the lateral surfaces of the
mediastinum, and the superior surface of the diaphragm are lined by
the parietal pleura.
• The potential space between the serous membrane layers is a pleural
cavity.
• The fluid inside the pleural cavity pleural fluid which acts as a
lubricant, ensuring minimal friction during breathing.

28. ALVEOLI
• Smallest bronchioles (respiratory bronchioles) have clusters (grapelike
clusters) of tiny sacs branching off = alveoli
• 300-500 Million alveoli/lung
• Enveloped by capillaries
• These are functional unit of respiratory system
• Actual site of gas exchange with blood

29. ALVEOLI

30. UPPER RESPIRATORY TRACT
INFECTIONS

31. • Infections of airway above glottis or vocal cords. It includes –
– Rhinitis
– Sinusitis
– Tonsillitis
– Pharyngitis
– Laryngitis
– Otitis media
URTIs

32. Rhinitis
• Rhinitis is inflammation and swelling of the mucous membrane of
the nose, characterized by a runny nose and stuffiness and usually
caused by the common cold or a seasonal allergy.
• Symptoms of rhinitis include a runny nose, sneezing, and stuffiness.
• Rhinitis is classified as allergic or nonallergic. The cause of
nonallergic rhinitis is usually a viral infection, although irritants can
cause it.

34. Cont..
• Rhinitis may be acute or chronic. Acute rhinitis commonly results
from viral infections but may also be a result of allergies, bacteria, or
other causes. Chronic rhinitis usually occurs with chronic sinusitis
(chronic rhinosinusitis).
• Typically, the diagnosis is based on the symptoms.
• The various forms of rhinitis are treated in various ways, such as with
antibiotics, antihistamines, surgery, desensitization injections
(sometimes called allergy shots), and avoidance of irritants.

35. Sinusitis
• Sinusitis is an inflammation, or swelling, of the tissue lining the sinuses.
• Sinuses are structures inside face that are normally filled with air.
Bacterial infections, viral infections and allergies can irritate them,
causing them to get blocked and filled with fluid.
• This can cause pressure and pain in face, nasal congestion (a stuffy
nose) and other symptoms.

37. Cont..
• Types of sinusitis
• According to duration: acute, subacute, chronic
• According to cause: bacterial, viral or fungal.
• Acute sinusitis symptoms last less than 4 weeks. It’s usually caused by
viruses like the common cold.
• Subacute sinusitis symptoms last 4 to 12 weeks.
• Chronic sinusitis symptoms last at least 12 weeks. Bacteria are usually
the cause.

38. Cont..
• Viruses, like the ones that cause the common cold (Rhinovirus,
Influenza virus, Para influenza virus), cause most cases of sinusitis.
• Bacteria (Streptococcus pneumoniae, Haemophiles influenzae) can
cause sinusitis, or they can infect after a case of viral sinusitis.
• Sinus infections caused by fungus are usually more serious than other
forms of sinusitis. They’re more likely to happen in weakened immune
system.

39. Cont..
• There are many treatment options for sinusitis, depending on the
symptoms and underlying causes. It includes –
• Intranasal steroid sprays.
• Antibiotics
• Topical antihistamine sprays or oral pills.
• Leukotriene antagonists, like montelukast.
• Surgery to treat structural issues, polyps or fungal infections.

40. Tonsillitis
• Tonsillitis is inflammation of the tonsils, two oval-shaped pads of
tissue at the back of the throat — one tonsil on each side.
• Tonsillitis is most often caused by common viruses, but bacterial
infections also can be the cause. The most common bacterium causing
tonsillitis is Streptococcus pyogenes (group A streptococcus)
• Signs and symptoms of tonsillitis include swollen tonsils, sore throat,
difficulty swallowing, fever and tender lymph nodes on the sides of
the neck.

42. Cont..
• Management
• The patient is advised to bed rest and consume high amounts of
fluids
• Analgesics such as paracetamol are given to relieve the pain
• Antibiotic therapy
• Tonsillectomy: usually performed only when tonsillitis occurs
frequently, doesn't respond to other treatments or causes serious
complications.

43. Pharyngitis
• The inflammation of pharynx is known as pharyngitis.
Etiology: Viruses are the commonest cause of pharyngitis although
bacteria and sometimes even fungi inflame the pharynx.
Clinical Features
1. Mild inflammation: low-grade fever, malaise and some discomfort in
the throat
2. Moderate to severe infections: headache, dysphagia, odynophagia,
malaise and high fever.
3. In very severe cases there can be edema of the soft palate and cervical
lymph node enlargement.

45. Cont..
Diagnosis
• The culture of throat swabs is helpful in identifying the bacterial
causative agents of pharyngitis.
Management
• Bed rest, increased fluid intake, gargling the throat with salt water and
analgesics are the main components in the management of pharyngitis.
• When the symptoms do not disappear spontaneously antibiotics such as
penicillin can be given. If the patient is allergic to penicillin,
erythromycin can be prescribed.

46. Laryngitis
• Laryngitis is an inflammation of voice box (larynx) from overuse,
irritation or infection.
Etiology
• Having a respiratory infection, such as a cold, bronchitis or sinusitis
• Exposure to irritating substances, such as cigarette smoke, excessive
alcohol intake, workplace chemicals
• Overusing your voice, by speaking too much, speaking too loudly,
shouting or singing
Symptoms: Hoarseness, Weak voice or voice loss, Tickling sensation,
Sore throat, Dry throat, Dry cough

48. Cont..
Types:
• Acute laryngitis: Most cases of laryngitis are temporary and improve
after the underlying cause gets better.
• Chronic laryngitis: Laryngitis that lasts longer than three weeks.
Diagnosis:
• Throat swab culture
• Laryngoscopy
• Biopsy

49. Cont..
Management
• Corticosteroids
• Antibiotics
• Pain medications: acetaminophen or ibuprofen.
• Voice therapy.
Prevention
• Avoid smoking and stay away from secondhand smoke
• Limit alcohol and caffeine
• Drink plenty of water
• Keep spicy foods out of your diet.
• Include a variety of healthy foods in your diet
• Avoid clearing your throat.
• Avoid upper respiratory infections

50. Otitis media
• Otitis media is a group of inflammatory diseases of the middle ear.
Types
1. Acute otitis media (AOM): an infection of rapid onset that usually
presents with ear pain. Most commonly found in young children.
2. Otitis media with effusion (OME): typically not associated with
symptoms, although occasionally a feeling of fullness is described. it
is defined as the presence of non-infectious fluid in the middle ear
which may persist for weeks or months often after an episode of acute
otitis media.
3. Chronic suppurative otitis media (CSOM): it is middle ear
inflammation that results in a perforated tympanic membrane with
discharge from the ear for more than six weeks.

52. Cont..
Etiology
• Either bacteria or viruses may be involved.
• Risk factors include exposure to smoke, use of pacifiers, and
attending daycare, having cleft lip and palate or Down syndrome.
Clinical manifestation
• Ear pain, fever, hearing loss, tenderness on touch of the skin above
the ear, purulent discharge from the ears, irritability, ear blocking
sensation.
Diagnosis
• Audiometry
• Tympanogram
• Temporal bone CT and MRI

53. Cont..
Management
• Oral and topical pain killers: Paracetamol (acetaminophen),
ibuprofen, benzocaine ear drops
• Antibiotics
Prevention
• Vaccination: PCV, pentavalent
• Exclusive Breastfeeding