Respiratory System – Comprehensive Review

A set of question-and-answer flashcards covering key anatomical structures, physiological processes, pathologies, and clinical correlations of the respiratory system as outlined in the lecture notes.

What are the two main divisions of the respiratory system based on location?

The upper respiratory system (structures above the larynx) and the lower respiratory system (structures below the larynx).

Name the three primary functions of the respiratory system.

Gas exchange, ventilation (moving air in and out), and air conditioning (warming, humidifying, filtering).

List three secondary functions of the respiratory system.

Sound production, olfaction, and defense via mucosa-associated lymphoid tissue (MALT).

Which structure divides the nasal cavity into right and left halves?

The nasal septum.

What is the role of the nasal conchae in the nasal cavity?

They increase surface area and create turbulence to condition incoming air.

What are the spaces beneath each nasal concha through which air flows?

The nasal meatuses.

Name the four paired paranasal sinuses.

Frontal, maxillary, sphenoid, and ethmoidal sinuses.

Give one function of the paranasal sinuses.

They lighten the skull (other functions: mucus production, sound resonance, brain insulation).

Which muscular tube serves as a common passageway for air and food?

The pharynx.

List the three regions of the pharynx.

Nasopharynx, oropharynx, and laryngopharynx.

Which cartilage forms the Adam’s apple?

The thyroid cartilage.

What is the space between the vocal folds called?

The rima glottidis.

Which structure connects the pharynx to the trachea?

The larynx.

State two primary functions of the larynx.

Sound production and protection of the lower respiratory tract during swallowing; it also conducts air to the trachea.

Approximately how long is the trachea?

About 10–12 cm.

What structural feature prevents the trachea from collapsing?

C-shaped cartilage rings.

Which smooth muscle connects the open ends of the tracheal cartilage rings?

The trachealis muscle.

What type of epithelium lines the trachea?

Pseudostratified ciliated columnar epithelium.

Name the first three levels of branching in the bronchial tree.

Main (primary) bronchi, secondary (lobar) bronchi, and tertiary (segmental) bronchi.

At which airway does gas exchange begin?

The respiratory bronchiole.

Describe the epithelial progression from bronchi to alveoli.

Pseudostratified ciliated columnar → simple columnar/cuboidal → simple squamous.

Which alveolar cells secrete surfactant?

Type II alveolar (septal) cells.

What is the main function of pulmonary surfactant?

It reduces surface tension, preventing alveolar collapse.

Which immune cells patrol the alveolar surfaces?

Alveolar macrophages.

How many lobes does the right lung have?

Three: superior, middle, and inferior.

What indentation on the left lung accommodates the heart?

The cardiac notch (with the lingula below it).

What is the name of the area where bronchi, blood vessels, and nerves enter the lung?

The hilum (forming the root of the lung).

Which pleural layer directly covers the lung surface?

The visceral pleura.

What is contained in the pleural cavity, and what is its function?

Pleural fluid, which reduces friction and creates surface tension to help lungs adhere to the thoracic wall.

During inspiration, what happens to the diaphragm?

It contracts and moves downward.

What happens to intrapulmonary (alveolar) pressure during inspiration?

It decreases below atmospheric pressure, drawing air in.

What is the primary driving force for gas diffusion at the alveoli?

Partial-pressure (concentration) gradients of O₂ and CO₂.

Define bronchoconstriction.

Narrowing of airways due to smooth muscle contraction.

Which autonomic division primarily mediates bronchodilation?

The sympathetic division (or inhibition of parasympathetic tone).

What pathological change characterizes emphysema?

Destruction of alveolar walls and loss of lung elasticity.

Name one major cause of emphysema.

Cigarette smoking (others: environmental toxins, α-1 antitrypsin deficiency, chronic inflammation).

List the three main types of lung cancer.

Squamous cell carcinoma, adenocarcinoma, and small cell carcinoma.

Identify the leading cause of lung cancer.

Smoking.

Which clinical tool measures lung volumes and capacities?

Spirometry.

Which imaging modality provides detailed cross-sectional views of respiratory structures?

Computed tomography (CT) scan.

What is bronchoscopy used for?

Direct visualization of the airways.

How do bronchodilators improve breathing?

They relax bronchial smooth muscle, widening the airways.

Which two brain regions contain the primary respiratory control centers?

The medulla oblongata and the pons.

What type of lymphoid tissue in the respiratory mucosa defends against pathogens?

Mucosa-associated lymphoid tissue (MALT).

Why does the upper respiratory tract possess pseudostratified ciliated epithelium with goblet cells?

To produce mucus and move trapped debris upward via the mucociliary escalator.

How does cartilage support change from trachea to bronchioles?

Trachea has full C-shaped rings; bronchi have cartilage plates; bronchioles have no cartilage—only smooth muscle.

Why are alveoli lined with simple squamous epithelium?

To minimize diffusion distance and maximize efficiency of gas exchange.

What combined structure consists of the vocal folds plus the rima glottidis?

The glottis.

Which paranasal sinus pair is the largest?

The maxillary sinuses.

What physiological reflex forcefully expels irritants from the lower airway?

The cough reflex.

Name two common inflammatory conditions of the respiratory tract.

Asthma and bronchitis (others include pneumonia and sinusitis).

What is the function of terminal bronchioles?

They are the smallest purely conducting airways, delivering air to respiratory bronchioles.

Which component helps the lungs follow chest wall movements during breathing?

Surface tension created by pleural fluid between visceral and parietal pleura.

How does the relative amount of smooth muscle change along the airway tree?

It increases proportionally in bronchioles, allowing active regulation of airway diameter.

Summarize the basic structure-function relationship of branching airways.

Airway diameter decreases while branch number increases, reducing resistance and maximizing surface area for gas exchange.