Respiratory System Practice Flashcards

These vocabulary flashcards cover the anatomy, physiology, pressures, and clinical disorders of the respiratory system based on the lecture transcript.

Conducting division

Organs that allow air to reach the lungs but do not exchange $O_2$ and $CO_2$, including the nose, pharynx, larynx, trachea, and most bronchi.

Respiratory division

The portion of the respiratory system that carries out gas exchange, including some smaller distal bronchi and alveoli.

Nasal cavity

A structure divided by a septum that warms, moistens, and filters air as it is inhaled.

Pharynx

Also known as the throat, it serves as a passageway for air and leads to the trachea.

Larynx

Also known as the voice box, it consists of 9 cartilages and holds the vocal cords.

Trachea

Also known as the windpipe, it is a tube that contains 16-20 C-rings of hyaline cartilage and descends to the primary bronchi.

Cilia

Fine hairs lining the trachea that filter air and move mucus away from the lungs toward the throat.

Bronchi

Two branches at the end of the trachea that lead to each lung.

Bronchioles

A network of smaller branches leading from the bronchi into lung tissue that contain smooth muscle innervated by the autonomic nervous system.

Alveoli

The functional respiratory units in the lung (totaling approximately 300 million) where gases are exchanged.

Nasal septum

The wall that divides the nasal cavity into two halves.

Respiratory epithelium

Pseudostratified ciliated columnar epithelium endowed with goblet cells that secrete mucus in the nasal cavity.

Conchae (turbinates)

Lateral wall protrusions in the nasal cavity that increase surface area and enhance air turbulence to trap particles.

Nasopharynx

The region posterior to the nasal cavity that houses the pharyngeal tonsils and serves only as an air passageway.

Adenoids

The common name for the pharyngeal tonsils located in the nasopharynx.

Uvula

The structure that moves superiorly to close off the nasopharynx during swallowing.

Oropharynx

The region posterior to the oral cavity that houses palatine and lingual tonsils and serves as a passageway for both air and food.

Laryngopharynx

The most inferior region of the pharynx where the respiratory and digestive systems diverge.

Epiglottis

A single elastic cartilage that closes off the glottis (laryngeal inlet) during swallowing.

Laryngeal prominence

Commonly known as the Adam's apple, it is the point of fusion of two thyroid hyaline cartilages.

True vocal cords

The inferior pair of vocal cords that vibrate as exhaled air rushes past them to determine pitch.

Heimlich maneuver

A procedure used to dislodge food stuck in the esophagus or throat that is preventing breathing.

Right primary bronchus

The branch of the trachea that descends into the right lung and further divides into 3 secondary (lobar) bronchi.

Left primary bronchus

The branch of the trachea that descends into the left lung and further divides into 2 secondary (lobar) bronchi.

Bronchodilation

The expansion of bronchial air passages caused by the activation of the sympathetic nervous system.

Bronchoconstriction

The narrowing of bronchial air passages caused by the activation of the parasympathetic nervous system.

Terminal bronchioles

The smallest bronchioles (less than $0.5\,mm$ in diameter) that are surrounded by alveoli and begin the respiratory division.

Cardiac notch

An indentation in the left lung used to accommodate the left ventricle of the heart.

Apex

The top portion of each lung that lies deep to the clavicles.

Alveolar type I cells

Squamous epithelial cells that form the alveolar wall and are surrounded by dense pulmonary capillaries.

Alveolar type II cells

Cuboidal epithelial cells dispersed in the alveolar wall that produce surfactant.

Surfactant

A detergent-like substance that reduces the surface tension of fluid lining alveoli to prevent collapse during expiration.

Parietal pleura

The outer layer of the serous membrane sac that surrounds each lung.

Visceral pleura

The layer of serous membrane that lies directly on the surface of the lung.

Pleural cavity

A slit-like potential space filled with pleural fluid between the parietal and visceral pleura.

$P_{atm}$ (Atmospheric pressure)

The pressure exerted by air surrounding the body, which is $760\,mmHg$ at sea level.

$P_{alv}$ (Intra-alveolar pressure)

The pressure of air in the alveoli, also known as intrapulmonary pressure ($P_{pul}$).

$P_{ip}$ (Intrapleural pressure)

The pressure inside the pleural sac, which is always negative relative to atmospheric pressure.

Transpulmonary pressure

The distending pressure across the lung wall, calculated as $P_{alv} - P_{ip}$, which keeps the alveoli open.

Pneumothorax

A condition where air enters the pleural cavity, breaking the seal holding the lung to the chest wall and causing the lung to collapse.

Pulmonary ventilation

Commonly known as breathing, it is the exchange of gas between atmospheric air and alveolar air in the lungs.

External respiration

The gas exchange between $O_2$ in alveolar air and $CO_2$ in blood in pulmonary capillaries across the respiratory membrane.

Internal respiration

The process of oxidative phosphorylation within the cells.

Inspiration

The phase of breathing where the diaphragm and external intercostal muscles contract, increasing thoracic volume and lowering intrapulmonary pressure.

Expiration

The phase of breathing that results from the passive, elastic recoil of the lungs, rib cage, and diaphragm during quiet breathing.

Boyle's Law

The principle stating that volume changes bring about pressure changes; used to drive air flow into and out of the lungs.

Ventral respiratory group (VRG)

A medullary center containing rhythm generators whose output drives respiration.

Dorsal respiratory group (DRG)

A medullary center that integrates peripheral sensory input and modifies the rhythms generated by the VRG.

Hypoventilation

Slow, shallow breathing that causes $CO_2$ to build up in the blood, leading to acidosis.

Hyperventilation

Rapid, deep breathing that causes $CO_2$ to be blown off, leading to alkalosis.

Dalton's Law

The law stating that the pressure exerted by a particular gas is directly proportional to the percentage of that gas in the total air mixture.

Anatomical dead space

The internal volume of the upper airways (nose, pharynx, trachea, bronchi) where no gas exchange occurs, typically equal to $150\,ml$ in a $150\,lb$ person.

MVR (Minute Ventilation Rate)

The volume of air inhaled or exhaled in a minute, calculated as $TV \times RR$.

AVR (Alveolar Ventilation Rate)

The volume of fresh air reaching the alveoli in the lungs in a minute, calculated as $(TV - ADS) \times RR$.

Ventilation-Perfusion coupling

The regulatory mechanism where alveoli with high $O_2$ levels receive more blood flow, while those with low $O_2$ receive less.

Respiratory membrane

The air-blood barrier where gas exchange occurs, measuring approximately $0.4\,micrometer$ thick.

Emphysema

A chronic obstructive lung disease where alveoli burst and fuse into enlarged air spaces, reducing surface area for exchange.

Asthma

A condition where airways are inflamed due to irritation and bronchioles constrict due to muscle spasms and thickened walls.

Cystic Fibrosis

An autosomal recessive disorder caused by a mutation on the CFTR gene, resulting in thick, sticky mucus production that clogs airways.

Chronic Bronchitis

Inflammation of the airways due to infection or irritants, leading to excess mucus, pus, and prolonged coughing.

Pulmonary Tuberculosis

An infection caused by a bacillus bacterium, causing symptoms like fatigue, chest pain, and coughing up blood.

Pulmonary fibrosis

The buildup of fibrous connective tissue in the lungs, which reduces elasticity and compliance.

Pneumonia

A condition where alveoli fill with pus and fluid, thickening the respiratory membrane and making gas exchange difficult.

Tidal volume (TV)

The amount of air inhaled or exhaled with each breath under resting conditions, typically around $500\,ml$.

Inspiratory reserve volume (IRV)

The amount of air that can be forcefully inhaled after a normal tidal volume inhalation, approximately $3100\,ml$ in males.

Expiratory reserve volume (ERV)

The amount of air that can be forcefully exhaled after a normal tidal volume exhalation, approximately $1200\,ml$ in males.

Residual volume (RV)

The amount of air remaining in the lungs after a forced exhalation, approximately $1200\,ml$.

Vital capacity (VC)

The maximum amount of air that can be expired after a maximum inspiratory effort, calculated as $TV + IRV + ERV$.

Oxyhemoglobin ($HbO_2$)

The combination of hemoglobin and oxygen.

Bohr effect

The effect by which the presence of $CO_2$ (low pH) decreases the affinity of hemoglobin for $O_2$, occurring in the tissues.

Haldane effect

The effect by which the combination of $O_2$ with hemoglobin displaces $CO_2$ from hemoglobin, occurring in the lungs.