The Respiratory System (Het Ademhalingsstelsel)

Cellular Respiration (Nutrient Combustion)

The biochemical process where cells utilize oxygen ($O_2$) to break down nutrients and release energy, producing carbon dioxide ($CO_2$) as a waste gas that must be exhaled.

Nasal Cavity (Air Conditioning Functions)

The primary entry point for inhalation that prepares incoming air by filtering particles with nasal hairs and mucus, moistening air via mucosal water release, and warming air through rich underlying blood vessels.

Olfactory Sensory Cells (Reukzintuigcellen)

Specialized sensory receptor cells positioned high inside the nasal cavity that detect scents to provide warnings against toxic substances, though they cannot detect all harmful gases.

Trachea (Luchtpijp)

A firm, hollow tube approximately $10\text{--}12\,cm$ long reinforced with $16\text{--}20$ cartilage rings (kraakbeenringen) that keeps the airway open and splits into bronchial branches.

Tonsils (Amandelen / Tonsillen)

Lymphatic structures located in the pharynx that generate immune defense substances against invading bacteria and are susceptible to inflammation (tonsillitis).

Epiglottis (Strotklepje)

A flap of elastic cartilage attached to the larynx that folds down to close off the trachea during swallowing, directing food into the esophagus.

Choking (Verslikken)

The event in which food particles accidentally enter the trachea because the epiglottis fails to seal the airway completely or quickly enough during swallowing.

Vocal Cords (Stembanden)

Vibrating folds of tissue located inside the larynx (strottenhoofd) that produce sound as air passes through them during exhalation.

Thoracic Cage (Borstkas)

The protective skeletal structure enclosing the lungs and heart, formed by the ribs (ribben), breastbone (borstbeen), and vertebrae (ruggenwervels).

Diaphragm (Middenrif / Diafragma)

A broad, dome-shaped muscle that forms the physical boundary between the chest cavity (borstholte) and the abdominal cavity (buikholte), driving ventilation.

Lung Asymmetry and Lobes

The anatomical difference between the lungs where the right lung has $3$ lobes and is larger, while the left lung has $2$ lobes and is smaller to accommodate the leftward tilt of the heart's apex.

Interpleural Cavity (Interpleurale Holte)

The thin, fluid-filled space between the pulmonary pleura (longvlies) covering the lungs and the parietal pleura (borstvlies) lining the inner chest wall, creating surface tension that keeps the lungs expanded against the rib cage.

Respiratory Pathway

The sequential anatomical route of inhaled air through the respiratory system: nasal cavity $\rightarrow$ pharynx $\rightarrow$ larynx $\rightarrow$ trachea $\rightarrow$ bronchi $\rightarrow$ bronchioles $\rightarrow$ alveoli.

Inhalation (Inademing)

The active phase of breathing where the intercostal muscles contract to lift the ribs upward and outward while the diaphragm contracts and flattens downward, expanding the volume of the thoracic cavity.

Exhalation (Uitademing)

The passive phase of quiet breathing where the intercostal muscles and diaphragm relax, moving the ribs downward and inward and the diaphragm upward into a dome shape to reduce thoracic volume.

Exertion Effect on Breath Holding

The biological principle that physical exertion increases cellular metabolic activity and $O_2$ consumption, which significantly reduces the number of seconds a person can hold their breath relative to rest.

Vital Capacity (Vitale Capaciteit)

The maximum volume of air an individual can forcefully expel from the lungs following a maximal deep inhalation, typically measured using a spirometer.

Determinants of Vital Capacity

The physiological and demographic factors causing individual variations in lung capacity, comprising physical conditioning, sex, height, age, body build, and overall health status.

Cobalt Chloride Paper (Kobaltchloridepapier)

A moisture-sensitive indicator paper that remains blue in dry air but turns pink/rose when exposed to water ($H_2O$), demonstrating the presence of water vapor in exhaled air.

Alveolar Gas Exchange (Stofuitwisseling in de Longen)

The process occurring across the thin walls of the alveoli and surrounding capillaries where $O_2$ diffuses into the bloodstream to bind to red blood cells, while waste $CO_2$ diffuses from the blood into the alveoli to be exhaled.

Respiratory Hygiene Guidelines

Practical