Respiratory System Anatomy and Physiology

Vocabulary-style flashcards covering the key terms, structures, and physiological processes of the respiratory system based on the lecture transcript.

Upper Respiratory Tract

The anatomical division of the respiratory system consisting of the nose, pharynx, and larynx.

Lower Respiratory Tract

The anatomical division of the respiratory system consisting of the trachea, bronchi, bronchioles, alveoli, lungs, and pleura.

Respiratory Epithelium

The ciliated mucosa lining the upper respiratory tract that warms, humidifies, secretes lysozyme, and filters and moves dust-laden mucus to the pharynx.

External Nares

The two external openings leading into the nasal cavity.

Nasal Conchae

Three bones (superior, middle, and inferior) extending from the nasal cavity wall that swirl air to enhance filtering, warming, and wetting during inhalation.

Pharynx

A tube of skeletal muscle extending from the internal nares to the 6th cervical vertebrae that acts as a common passageway for food and air, houses tonsils, and serves as a resonance chamber.

Nasopharynx

The superior division of the pharynx lined with pseudostratified epithelium, blocked by the soft palate and uvula during swallowing, which houses the pharyngeal tonsil (adenoids) and connects to the middle ear via Eustachian tubes.

Eustachian Tubes

Left and right pharyngotympanic tubes connecting the nasopharynx to the middle ear to equalise pressure and prevent ear damage.

Oropharynx

The middle division of the pharynx lined by resilient stratified squamous epithelium that contains the pair of palatine tonsils and the lingual tonsil.

Laryngopharynx

The inferior division of the pharynx lined with stratified squamous epithelium that connects with both the oesophagus and larynx.

Larynx

The voice box, a cartilaginous tube lined with mucous membrane situated anterior to vertebrae C4 to C6.

Epiglottis

A large piece of cartilage in the larynx that covers the larynx during swallowing.

Thyroid Cartilage

The large piece of cartilage forming part of the laryngeal box, commonly known as the Adam's Apple.

Cricoid Cartilage

A large piece of laryngeal cartilage that serves as the anchor for the trachea.

Internal Laryngeal Muscles

Muscles within the larynx that control vocal cord length and tension.

External Laryngeal Muscles

Muscles that control the movement of the whole larynx up and down during swallowing, ventilation, and vocalisation.

Trachea

A flexible and mobile air tube lined with ciliated mucous membrane and supported by 16 to 20 C-shaped bands of cartilage.

Right Lung

The larger and heavier lung consisting of three distinct lobes (Superior, Middle, and Inferior) separated by horizontal and oblique fissures.

Left Lung

The lung divided into two lobes (Superior and Inferior) separated by a single oblique fissure, containing a cardiac notch and lingula.

Cardiac Notch

An indentation on the anterior border of the left lung that accommodates the space occupied by the heart.

Lingula

A tongue-like projection on the superior lobe of the left lung that is functionally analogous to the middle lobe of the right lung.

Pores of Kohn

Tiny passages in alveoli that allow them to pass air to each other.

Type 1 Epithelial Cells

Epithelial cells forming alveolar walls that function specifically in gas exchange.

Type 2 Epithelial Cells

Alveolar epithelial cells that secrete surfactant consisting of lipoproteins and phospholipids.

Pulmonary Ventilation

The mechanical movement of air in and out of the lungs so that gases in the alveoli are continuously changed and refreshed.

Inspiration

The process of breathing in, driven by the development of negative pressure within the chest allowing air to flow down a pressure gradient into the lungs.

Expiration

The process of breathing out, where thoracic volume decreases, increasing intrathoracic pressure and forcing air out.

External Respiration

The exchange of gases occurring at the alveoli, where oxygen diffuses into pulmonary capillaries and carbon dioxide diffuses into the alveoli.

Internal Respiration

The exchange of $O_2$ and $CO_2$ between systemic capillaries and tissue cells throughout the body.

Oxyhaemoglobin

The compound formed when oxygen binds to hemoglobin inside erythrocytes, carrying $98.5\%$ of oxygen in the blood.

Carbaminohaemoglobin

The form in which approximately $23\%$ of carbon dioxide is transported bound to blood proteins.

Bicarbonate Ions ($HCO_3^-$)

The predominant form ($70\%$) in which carbon dioxide is transported in blood plasma, generated via the reaction $H_2CO_3 \rightleftharpoons H^+ + HCO_3^-$.

Ventral Respiratory Group (VRG)

A group of respiratory control neurons located within the medulla oblongata.

Dorsal Respiratory Group (DRG)

A cluster of neurons in the medulla oblongata involved in the neural control of breathing rhythm.

Pontine Respiratory Group (PRG)

A group of respiratory control neurons located in the pons.

Central Chemoreceptors

Sensory receptors located in the brain stem that respond to chemical changes such as arterial $PCO_2$ and pH to influence breathing.

Peripheral Chemoreceptors

Sensory receptors located in the aortic arch and carotid arteries that monitor blood arterial levels of $PO_2$, $PCO_2$, and pH.