Respiratory System Overview Quiz

The system responsible for gas exchange between the body and the environment, allowing for the intake of oxygen and the expulsion of carbon dioxide.

The network of tubes that carry air from the nose and mouth to the lungs.

The area in the lungs where gas exchange occurs, involving the transfer of oxygen into the bloodstream and carbon dioxide out.

Small, air-filled sacs in the lungs where the exchange of oxygen and carbon dioxide between the air and the blood takes place.

The process of moving air into and out of the lungs, involving the expansion and contraction of the chest cavity.

The outer part of the nasal cavity, containing hairs (vibrissae) that filter out large particles from inhaled air.

The type of epithelium found lining the nasal cavities, characterized by multiple layers of cells, including goblet cells that produce mucus.

Specialized sensory epithelium located in the nasal cavity responsible for detecting odors.

Two chambers within the skull separated by the nasal septum, responsible for warming, humidifying and filtering inhaled air.

Three bony projections extending from the lateral walls of the nasal cavities, increasing surface area for air conditioning.

The tissue lining the nasal cavities, responsible for warming, humidifying and filtering inhaled air.

A vascular network in the nasal mucosa, carrying blood counter to the airflow to release heat and warm inhaled air.

The fluid secreted by the nasal mucosa, trapping small particles and microorganisms.

An antibody present in nasal mucosa, binding to microbes and contributing to their inactivation.

Neurons within the olfactory epithelium responsible for detecting odoriferous substances.

The knob-like swelling at the end of olfactory neurons, containing cilia for odor detection.

The non-motile hair-like extensions of olfactory neurons, providing a large surface area for odor receptors.

The axons of olfactory neurons, carrying odor signals to the olfactory bulb in the brain.

Specialized cells in the olfactory epithelium supporting olfactory neurons, maintaining the microenvironment for smell function.

Stem cells in the olfactory epithelium responsible for replacing olfactory neurons and supporting cells.

The type of epithelium lining most of the conducting airways, characterized by its ciliated pseudostratified columnar structure.

Cells within the respiratory epithelium, responsible for secreting mucus to trap inhaled particles and microorganisms.

This is a term describing structures within the skull that connect to the nasal cavities, lined with a thinner version of the respiratory epithelium, and containing a few small glands.

A large, serous gland found in the lamina propria of the olfactory epithelium, producing fluid that helps carry odor molecules to the olfactory cilia.

Tiny hair-like structures on the surface of ciliated columnar epithelial cells that move in a coordinated manner to propel mucus and trapped particles upward.

The first part of the pharynx located behind the nasal cavities, lined with respiratory mucosa and containing openings for the auditory tubes.

The middle part of the pharynx located behind the oral cavity, characterized by non-keratinized stratified squamous epithelium and containing tonsils.

The lowest part of the pharynx, connecting to the larynx and esophagus, lined with non-keratinized stratified squamous epithelium.

A short passage for air connecting the pharynx and trachea, composed of cartilage and muscle tissue.

An inherited disorder characterized by defective ciliary action, causing chronic sinusitis and bronchitis.

A condition involving inflammation of the paranasal sinuses, often caused by obstruction of drainage orifices.

The process of the olfactory epithelium detecting odor molecules.

A condition where the sense of smell is reduced.

A condition where the sense of smell is completely lost.

The larynx is a short, tubular passage that connects the pharynx to the trachea and is specialized for sound production. It contains cartilages, muscles, and a lining that allows it to produce sounds.

The larynx is supported by a framework of nine cartilages. The three largest are the thyroid cartilage, cricoid cartilage, and the epiglottis, while the six smaller cartilages are the arytenoid cartilages (superior and inferior), corniculate cartilages, and cuneiform cartilages.

The epiglottis, a leaf-shaped cartilage, is located at the top of the larynx. It acts as a valve, preventing food and liquid from entering the trachea during swallowing.

The inner lining of the larynx is covered by epithelial tissue. The upper part is lined by stratified squamous epithelium, which is resistant to abrasion. The lower part is lined by ciliated pseudostratified columnar epithelium, which helps move mucus and debris.

The vocal folds are two folds of tissue located in the larynx. They are covered in stratified squamous epithelium and contain a vocal ligament and vocalis muscle.

Sound production, or phonation, occurs when air is expelled from the lungs and passes over the vibrating vocal folds. The tension and position of the vocal folds, along with the volume of air, affect the pitch and quality of sound.

The trachea is a tube that carries air from the larynx to the lungs. It is composed of C-shaped rings of hyaline cartilage, which keep it open and prevent it from collapsing.

The inner lining of the trachea is covered by pseudostratified columnar epithelium, which contains cilia and goblet cells. The cilia move mucus and debris upward, while goblet cells produce mucus to trap foreign particles.

The trachea branches into two primary bronchi, one for each lung. These bronchi then divide into secondary bronchi (lobular bronchi) and tertiary bronchi (segmental bronchi).

The bronchi continue to branch into smaller and smaller tubes, eventually forming bronchioles. These bronchioles terminate in alveoli, the small air sacs where gas exchange takes place.

Inflammation of the larynx, or laryngitis, can occur due to viral infection or irritation. It causes swelling and can lead to hoarseness or loss of voice.

Croup is a condition that mainly affects young children, causing swelling in the larynx and trachea. It results in a harsh, barking cough and hoarseness.

A cough is a reflex that aims to clear the respiratory tract of irritants or mucus. It involves a forceful expulsion of air from the lungs.

Cough suppressants are medications that can help reduce the frequency of dry coughs by acting on the brain and nerves involved in cough reflex.

Expectorants are medications that help loosen mucus in the respiratory tract, making it easier to cough up.

Vocal nodules, also known as "singer's nodules", are benign growths on the vocal cords. They are commonly found in the stratified squamous epithelium of the true vocal cords and can affect the voice.

The trachea is a tube that connects the larynx to the bronchi, acting as a passageway for air to and from the lungs. It is approximately 10-12 cm long in adults.

The trachea's inner lining is composed of respiratory mucosa, a type of tissue that lines the airways. It contains numerous seromucous glands that produce mucus, which helps to trap foreign particles and keep the airway moist.

The tracheal wall is reinforced by a series of C-shaped rings of hyaline cartilage, located between the submucosa and adventitia. These rings help to maintain the open lumen of the trachea, preventing it from collapsing.

The open ends of the cartilage rings in the trachea are on the posterior surface, facing the esophagus. These openings are bridged by a bundle of smooth muscle called the trachealis muscle and a sheet of fibroelastic tissue.

The trachealis muscle relaxes during swallowing, allowing the esophagus to bulge into the tracheal lumen. This helps facilitate the passage of food without blocking the airway.

The trachealis muscle contracts forcefully during coughing. This narrowing of the tracheal lumen increases air velocity, aiding in the expulsion of foreign materials from the airway.

The tertiary bronchi, along with their smaller branches, form bronchopulmonary segments within the lungs. Each segment has its own connective tissue capsule and blood supply and makes up about 10-12% of the lung.

Bronchopulmonary segments allow for the surgical resection of diseased lung tissue without significantly impacting the nearby healthy tissue.

Tertiary bronchi branch into smaller bronchi and eventually into bronchioles, the smallest branches of the bronchial tree.

Each bronchiole enters a pulmonary lobule, a pyramid-shaped segment of the lung, where it branches to form five to seven terminal bronchioles.

The bronchial tree, along with the alveoli, constitutes the vast surface area of the lungs, making them highly susceptible to inhaled pathogens.

The histological structure of the epithelium and lamina propria gradually simplifies as you move from larger bronchi to the smaller bronchioles.

Larger bronchi have cartilage rings that completely encircle their lumen, but these rings are replaced by smaller isolated plates of cartilage as the bronchi decrease in size.

The lamina propria of the bronchi contains bundles of smooth muscle and elastic fibers, which become more prominent as the bronchi become smaller.

The smallest bronchioles, marking the end of the conducting portion of the airway and the beginning of the respiratory portion where gas exchange takes place. They are characterized by a simple cuboidal epithelium with cilia and club cells, a thin smooth muscle layer, and the absence of cartilage.

Specialized cells found in the epithelium of terminal bronchioles and respiratory bronchioles. They play a crucial role in protecting the respiratory system by secreting surfactant, detoxifying harmful substances, and producing antimicrobial peptides.

The smooth muscle layer in the bronchioles and bronchi is responsible for regulating airflow by contracting and relaxing. This allows for bronchoconstriction (narrowing) and bronchodilation (widening), important for controlling air resistance.

A common condition characterized by chronic inflammation and bronchospasms (sudden constrictions of smooth muscle in bronchioles). These spasms make it difficult to breathe and can range from mild to severe.

The process of moving mucus and trapped particles upward along the airway, eventually leading to their removal from the body.

Specialized cells lining the alveoli that facilitate gas exchange. Type I are thin and squamous, maximizing surface area for efficient gas diffusion. Type II produce surfactant, reducing surface tension in alveoli to prevent collapse.

A substance produced by type II alveolar cells, reducing surface tension in alveoli and preventing them from collapsing. This is crucial for proper gas exchange.

Muscular contractions that narrow the lumen of bronchioles, increasing resistance to airflow. It can be triggered by allergens, infections, or other irritants.

A condition in which the bronchioles become inflamed and narrowed, making it difficult to breathe. It's often caused by infection, allergies, or environmental irritants.

The airway passages that conduct air from the trachea to the respiratory bronchioles. They are characterized by the presence of smooth muscle, cartilage, and a lining of pseudostratified columnar epithelium.

The thin layer of connective tissue that surrounds the bronchiole epithelium, containing smooth muscle, elastic fibers, and blood vessels.

A type of bronchiole that is the first part of the respiratory region in the lungs, where gas exchange occurs, and has alveoli, the sites of gas exchange.

A condition where the airways are obstructed, often due to excessive mucus or aspirated material. This can lead to the collapse of lung lobules as blood absorbs gases from affected alveoli.

A condition where the walls of the alveoli are damaged, often caused by respiratory infections, toxic gas inhalation, or other injuries. This impairs gas exchange and can lead to severe breathing difficulties.

Tubes that branch off from the respiratory bronchioles, lined with openings of alveoli. They carry air from the respiratory bronchioles to the alveolar sacs.

Clusters of alveoli that form the ends of alveolar ducts. They represent the final point where air reaches in the lungs before gas exchange.

The thin layer of connective tissue surrounding the alveoli, containing a network of blood capillaries that facilitate gas exchange.

The structure that supports the trachea, composed of C-shaped rings of hyaline cartilage that prevent the airway from collapsing.

The muscular layer of the trachea, responsible for contracting and relaxing to help regulate airflow during breathing.

The inner lining of the trachea, composed of pseudostratified ciliated columnar epithelium, which helps move mucus and trapped particles out of the airway.

A specialized type of epithelium found in the respiratory bronchioles and alveoli, consisting of very thin, flat cells that allow for efficient gas exchange.

The layer of connective tissue below the epithelial layer in the trachea, containing blood vessels, nerves, and glands. It helps support the airway and provides nutrients to the epithelium.

Tiny pores connecting adjacent alveoli, equalizing pressure and allowing alternate air flow if a bronchiole is blocked.

Thin layers separating air in the alveolus from blood in capillaries, facilitating efficient gas exchange.

Branching tubes leading from the trachea to the alveoli, carrying air to the respiratory portion of the lungs.

Small, tube-like structures branching from the bronchi, delivering air to the alveoli.

The layer of tissue surrounding each alveolus, containing capillaries, elastic fibers, and connective tissue, supporting gas exchange and lung elasticity.

Thin, flat cells lining the alveoli, allowing for easy diffusion of gases between air and blood.

The network of blood vessels surrounding the alveoli, bringing deoxygenated blood and carrying away oxygenated blood.

The spongy, elastic structure containing the bronchioles and alveoli, responsible for gas exchange.

The process of gas exchange between the air in the alveoli and the blood in the capillaries.

The tiny blood vessels that supply the lungs themselves with blood, delivering nutrients and removing waste.

The pressure difference between the air in the alveoli and the blood in the capillaries, driving gas exchange across the respiratory membrane.

Extremely thin cells lining the alveoli, forming the blood-air barrier and allowing gas exchange.

Cuboidal cells interspersed among Type I cells, responsible for producing and releasing surfactant.

A complex mixture of lipids and proteins secreted by Type II alveolar cells, which reduces surface tension in the alveoli.

A phospholipid found in surfactant, essential for its surface tension-reducing properties.

Proteins found in surfactant, aiding in its function and providing immune protection.

The process by which Type I and Type II alveolar cells and macrophages remove surfactant from the alveoli.

A condition that occurs in premature infants due to a lack of sufficient surfactant, leading to respiratory distress.

The thin membrane where gas exchange occurs between the air in the alveoli and the blood in the capillaries.

Cells that reside in the alveoli, engulfing dust particles and other debris.

A receptor protein found on the surface of Type II alveolar cells, which binds to the SARS-CoV-2 virus.

The main target cell for SARS-CoV-2 in the lungs, leading to infection and potential respiratory complications.

Spike proteins on the coronavirus bind to ACE2 receptors on type II alveolar cells, initiating the entry of the virus into the cell through endocytosis. This process involves the virus-enzyme complex being transported into the cell's endosomal system. Inside the endosome, the viral coat is disassembled, releasing the RNA genome, which then replicates and transcribes to initiate the production of new viruses.

Infected cells experience a reduction in surfactant production, leading to alveolar collapse. This collapse results in reduced gas exchange between oxygen (O2) and carbon dioxide (CO2) in the lungs, causing varying levels of hypoxia (low oxygen levels).

Alveolar macrophages are immune cells found in the alveoli and the interalveolar septum. They play a crucial role in defending the lungs against inhaled particles and microorganisms. Daily, millions of monocytes migrate from the bloodstream into the lung tissue to become alveolar macrophages.

Alveolar macrophages can be distinguished from type II pneumocytes because they appear darker due to their accumulation of dust, carbon particles, and complexed iron (hemosiderin) from phagocytized red blood cells.

Filled alveolar macrophages have different fates: most migrate into bronchioles and are transported upward via the mucociliary apparatus, eventually being swallowed; others exit the lungs through the lymphatic system; and some remain in the interalveolar septum connective tissue for years.

Alveolar lining fluids are also removed via the conducting passages through ciliary activity. These secretions combine with bronchial mucus to form bronchoalveolar fluid, which helps remove particulate matter from inhaled air.

Bronchoalveolar fluid is bacteriostatic, meaning it can inhibit the growth of bacteria. It contains lysozyme and other protective agents produced by club cells, type II alveolar cells, and alveolar macrophages, all contributing to the defense of the lungs.

Heart failure cells are alveolar macrophages that have phagocytosed erythrocytes in cases of congestive heart failure. They are identified by a positive histochemical reaction for iron pigment (hemosiderin).

Type II alveolar cells are responsible for producing pulmonary surfactant, which is essential for maintaining the stability and expansion of alveoli. These cells have unusual lamellar bodies, which contain newly synthesized pulmonary surfactant.