Chapt 7: Respiratory Anatomy and Physiology — Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key anatomical structures, physiological concepts, and clinical implications from the notes on respiratory anatomy and anesthesia considerations.

Respiratory system

The upper and lower airways, lungs, and respiratory muscles; its core role is gas exchange (deliver O2 to blood, remove CO2) and it helps regulate acid-base balance, synthesize surfactant, and provide immune defense.

Gas exchange

The transfer of oxygen into the blood and carbon dioxide out of the blood at the alveolar-capillary interface.

Surfactant

A lipid-protein mixture produced by type II alveolar cells that reduces alveolar surface tension and prevents collapse of the alveoli.

Acid-base homeostasis

Maintenance of blood pH, influenced by CO2 levels and gas exchange in the lungs.

Upper airway anatomy

Structures including the nose, mouth, pharynx, and larynx that condition inspired air before it reaches the lungs.

Nose

Filters, warms, and humidifies inspired gases; contains a nasal septum, conchae, mucosa, and rich blood supply; major arteries come from internal/external carotids.

Nasal blood supply and epistaxis risk

Nasal arteries arise from branches of the carotids; nosebleeds are common during procedures and vasoconstrictors like phenylephrine can reduce bleeding.

Mouth anatomy

Teeth, tongue, hard and soft palates; lined with squamous epithelium; salivary glands lubricate and humidify air.

Pharynx

Muscular tube divided into nasopharynx, oropharynx, and laryngopharynx; muscle tone helps keep the airway open and can relax under anesthesia, risking obstruction.

Larynx

Cartilaginous structure with epiglottis, arytenoids, and vocal cords; has supraglottic, glottic, and subglottic regions; closes during swallowing to prevent aspiration.

Cricoid cartilage

Palpable airway landmark used for cricothyrotomy; cricoid pressure (Sellick maneuver) may reduce aspiration risk during intubation (controversial).

BURP maneuver

Backward, upward, rightward pressure on the larynx to improve laryngoscopy visualization.

Nasal cavity innervation (CN V)

Innervated by branches of the trigeminal nerve (CN V1 and V2); topical anesthetics can aid awake nasal intubation.

Glossopharyngeal nerve (CN IX)

Sensory supply to the mouth and pharynx; anesthetic sprays can facilitate awake orotracheal intubation.

Laryngeal innervation (CN X)

Sensation above cords by the superior laryngeal nerve and below cords by the recurrent laryngeal nerve; blocks are used in awake airway management.

Trachea

Muscular tube with C-shaped cartilage rings that bifurcates at the carina into right and left mainstem bronchi; the right bronchus is wider and more vertical.

Carina

The ridge at the tracheal bifurcation; anatomy predisposes aspirated material to enter the right lung.

Mainstem bronchi (right vs left)

Right mainstem bronchus is wider and more vertical, increasing risk of aspiration and misplacement of tubes.

Bronchi and bronchioles

Conducting airways that carry air but do not perform gas exchange; lined with respiratory epithelium, goblet cells, and cilia for clearance.

Mucociliary escalator

Ciliated epithelium and mucus layer that clear debris from the airway; impaired by inflammation or endotracheal tubes.

Alveoli

Primary site of gas exchange; clusters of tiny sacs with type I (gas exchange) and type II (surfactant production) cells, plus alveolar macrophages.

Type I alveolar cells

Thin cells specializing in gas exchange across the alveolar membrane.

Type II alveolar cells

Cells that produce surfactant to reduce surface tension and help keep alveoli open.

Alveolar macrophages

Immune cells within alveoli that defend against inhaled pathogens.

Respiratory bronchioles

Small airways contributing about 10% of gas exchange in the peripheral lung.

Pulmonary arteries

Deoxygenated blood from the right heart that delivers blood to the alveolar capillaries for gas exchange.

Pulmonary veins

Return oxygenated blood from the lungs to the left atrium.

Bronchial arteries

Systemic arteries (from aorta) that supply oxygenated blood to the bronchial tissues.

Pleura

Visceral pleura covers the lungs; parietal pleura lines the chest wall; the pleural space contains a small amount of fluid and maintains a negative pressure.

Pleural space pressure

A negative pressure (approximately -5 cm H2O) helps keep the lungs expanded within the chest.

Pneumothorax

Air in the pleural space that can cause partial or complete lung collapse (atelectasis).

Hemothorax

Blood in the pleural space, potentially compromising lung expansion.

Empyema

Pus in the pleural space due to infection.

Pleural effusion

Fluid accumulation in the pleural space.

Lung compliance

Ease with which the lungs expand; influenced by tissue elasticity and alveolar surface tension; surfactant lowers surface tension to improve compliance.

Functional residual capacity (FRC)

Gas remaining in the lungs after a normal exhalation; provides oxygen reserve during apnea; altered in COPD and restrictive diseases.

COPD (chronic obstructive pulmonary disease)

Chronic lung disease with increased lung compliance and reduced elasticity; typically shows increased FRC.

Restrictive lung disease

Lung diseases with low compliance and high elasticity, leading to decreased FRC.

Thorax and respiratory mechanics

Cone-shaped chest cavity supported by the spine and ribs; diaphragmatic and rib movements expand the thorax to draw in air.

Prone positioning

Face-down position that can limit thoracic expansion; requires ensuring abdominal freedom to allow ventilation.

Lung volumes and capacities (overview)

Key metrics include tidal volume, minute ventilation, total lung capacity, residual volume, and FRC, reflecting how much air is moved and stored during respiration.

Minute ventilation

Total volume of gas inhaled and exhaled per minute (tidal volume × respiratory rate).

Tidal volume

Volume of air moved per normal resting breath.

Total lung capacity (TLC)

Maximum amount of air the lungs can hold after a maximal inhalation.

Residual volume

Amount of air remaining in the lungs after a maximal exhalation.

Ventilation-perfusion (V/Q) matching

Efficient gas exchange requires matching of airflow (ventilation) and blood flow (perfusion) at the alveolar level.

Dead space ventilation

Ventilated but non-perfused alveoli, which primarily affects CO2 elimination (e.g., pulmonary embolism).

Shunt (physiologic)

Perfused but non-ventilated alveoli, leading to impaired oxygenation (e.g., atelectasis).

Aerosolized/topical anesthesia in airway management

Use of anesthetic sprays or blocks to facilitate awake nasal/oral intubation and reduce airway reflexes.

Protective airway reflexes during anesthesia

Coordination of pharynx and larynx to prevent aspiration; these reflexes are blunted by general anesthesia, requiring vigilance during induction and emergence.

Laryngospasm

Involuntary closure of the vocal cords in response to irritation, a potentially dangerous emergency during anesthesia.

Vagus nerve (CN X) and laryngeal branches

CN X gives rise to superior and recurrent laryngeal nerves that innervate the larynx and contribute to sensation and motor control.

Epiglottis

Flexible leaf-shaped flap that covers the glottis during swallowing to prevent aspiration.

Adam’s apple / thyroid cartilage

The prominent cartilage of the larynx (thyroid cartilage) often called the Adam’s apple.