Respiratory System Lecture Notes

A comprehensive set of vocabulary flashcards covering the anatomy, segments, functions, and regulation of the respiratory system based on the lecture transcript.

External nose

The structure that encloses the chamber for air inspiration.

Nasal cavity

A chamber designed for cleaning, warming, and humidifying inspired air.

Pharynx

The throat; a shared passageway for both food and air.

Larynx

The voice box, located in the anterior throat and extending from the base of the tongue to the trachea.

Trachea

The windpipe; an air cleaning tube that funnels inspired air to each lung.

Bronchi

Tubes that direct air into the lungs.

Alveoli

Small air-filled sacs and sites for external respiration where gas exchange between air and blood occurs.

Upper respiratory tract

The segment of the respiratory system extending from the nose to the larynx.

Lower respiratory tract

The segment of the respiratory system extending from the trachea to the alveoli in the lungs.

Conducting zone

The part of the respiratory system from the nose to the air tubes within the lungs used strictly for ventilation.

Respiratory zone

Small air tubes in the lungs and the alveoli where gas exchange actually occurs.

Ventilation

Breathing; the movement of air into and out of the lungs.

External respiration

The exchange of $O_2$ and $CO_2$ between the air in the lungs and the blood.

Gas transport

The process by which $O_2$ and $CO_2$ travel in the blood to and from cells.

Internal respiration

The exchange of $O_2$ and $CO_2$ between the blood and the tissues.

Paranasal sinuses

Air-filled spaces within bone that open into the nasal cavity and are lined with mucous.

Conchae

Bony projections on each side of the nasal cavity that increase surface area and help in cleaning, humidifying, and warming air.

Nasolacrimal ducts

Ducts that carry tears from the eyes and open into the nasal cavity.

Nares

The nostrils; the external openings leading into the nasal cavity.

Choana

The openings from the nasal cavity leading into the pharynx.

Olfactory epithelium

Tissue responsible for the sense of smell, located in the most superior part of the nasal cavity.

Nasopharynx

The uppermost portion of the pharynx that takes in air.

Oropharynx

The portion of the pharynx that extends from the uvula to the epiglottis.

Laryngopharynx

The portion of the pharynx extending from the epiglottis to the esophagus.

Uvula

An extension of the soft palate, meaning "little grape".

Thyroid cartilage

The largest piece of laryngeal cartilage, commonly called the Adam’s apple.

Epiglottis

A piece of cartilage that acts as a flap to prevent swallowed materials from entering the larynx.

Vestibular folds

The false vocal cords.

Vocal folds

The true vocal cords; the source of voice production that vibrates when air moves past them.

Tracheal rings

The $16$ to $20$ C-shaped pieces of cartilage that line the trachea.

Carina

The location where the trachea divides into the right and left main bronchi.

Respiratory bronchioles

The smallest bronchioles that have a few attached alveoli.

Alveolar ducts

Structures that arise from the respiratory bronchioles and open into the alveoli.

Respiratory Membrane

The very thin layer formed by the walls of alveoli and capillaries where gas exchange occurs via diffusion.

Thoracic cavity

The space enclosed by the thoracic wall and the diaphragm.

Diaphragm

A sheet of skeletal muscle that separates the thoracic cavity from the abdominal cavity.

Pulmonary arteries

Vessels that carry deoxygenated blood to the pulmonary capillaries.

Pulmonary veins

Vessels that return oxygenated blood from the lungs to the heart.

Parietal pleura

The membrane that lines the thoracic cavity.

Visceral pleura

The membrane that covers the surface of the lungs.

Dorsal respiratory group (DRG)

Part of the medullary respiratory center that is most active during inspiration.

Ventral respiratory group (VRG)

Part of the medullary respiratory center active during both inspiration and expiration.

pre-Botzinger complex (preBotc)

The region believed to establish the basic rhythm of respiration.

Lung recoil

The process where the expanded lung decreases in size during quiet expiration due to elastic fibers and fluid film.

Surfactant

A mixture of lipoproteins produced by secretory cells of the alveoli that prevents the lungs from collapsing.

Hypoxia

A decrease in $P_{O2}$ which triggers an increase in the respiratory rate.

Hypercapnia

An increase in $P_{CO2}$ that results in an increase in the rate and depth of ventilation.

Hypocapnia

A decrease in $P_{CO2}$ that causes a decrease in the rate of ventilation.

Hering-Breuer reflex

A reflex that limits the depth of inspiration to prevent overinflation of the lungs.