Respiratory System Anatomy and Physiology

The respiratory system allows air to enter and exit the body and facilitates gas exchange with the bloodstream. It also helps regulate blood pH, filters air, and contains smell receptors.

The portion of the respiratory system encompassing the nose and pharynx.

The part of the respiratory system containing the larynx, trachea, bronchi, and lungs.

The nasal cavity contains the nasal septum, conchae, and meatuses. It's lined with different types of epithelium for filtering and olfaction.

The nasal septum is made of hyaline cartilage, and bony components— vomer, perpendicular plate of the ethmoid, maxillae, and palatine bones.

The paranasal sinuses lighten the skull and contribute to voice resonance.

The nasal conchae create turbulence in the inhaled air, increasing contact time with the nasal mucosa, promoting warming and humidification.

The nasal meatuses are spaces between the conchae that increase the surface area for air flow, allowing for better filtering and warming.

The nasal cavity is lined with pseudostratified ciliated columnar epithelium, which traps dust and pathogens in mucus, then moves the mucus towards the pharynx.

During exhalation, the ciliated columnar epithelium helps reabsorb moisture from the air, preventing dehydration.

Choanae are the openings at the back of the nasal cavity, connecting it to the pharynx. They allow air to flow from the nose to the pharynx.

The pharynx is a muscular tube that serves as a common pathway for air to the larynx and food to the esophagus.

The pharynx is divided into three regions: nasopharynx, oropharynx, and laryngopharynx, each with distinct functions and linings.

The different sections of each lung, responsible for gas exchange.

C-shaped rings in the trachea and plates in the bronchi, providing structural support to maintain an open airway.

Muscle fibers in the walls of bronchi and bronchioles, regulating airflow by contracting or relaxing.

Transition zone for air between the conducting (airflow) and respiratory (gas exchange) zones.

Passageways that lead from respiratory bronchioles to alveolar sacs, allowing airflow into the alveoli for gas exchange.

Clusters of alveoli, maximizing the surface area for gas exchange between air and blood.

Tiny air sacs, the primary gas exchange sites where oxygen enters the blood and carbon dioxide leaves.

The inner membrane covering the lungs directly, protecting them and reducing friction during breathing.

The outer membrane lining the thoracic cavity, protecting the lungs and allowing smooth movement during breathing.

Tiny blood vessels surrounding the alveoli, where gas exchange occurs.

The epiglottis is a leaf-shaped flap that covers the trachea during swallowing, preventing food and liquids from entering the airway.

The glottis is the space between the vocal cords in the larynx, involved in sound production and regulating airflow into the trachea.

The rima glottidis is the opening between the vocal folds, allowing airflow during breathing and contributing to voice production.

C-shaped rings of cartilage provide structural support to the trachea, keeping it open for airflow and allowing for expansion during swallowing.

The trachea, a flexible tube, carries air from the larynx to the bronchi, while also trapping dust and microbes with mucus and cilia.

The vestibular folds, located above the true vocal cords, protect the vocal cords and control airflow during breathing. They also help with activities like coughing.

Vocal cords are folds of tissue that vibrate to produce sound when air passes through them. Their tension and length determine the pitch of the sound.

The carina marks the point where the trachea splits into the left and right primary bronchi. It contains sensitive receptors that trigger coughing when irritants are detected.

Terminal bronchioles, the smallest bronchi, are the end of the air conduction pathway, passing air to the respiratory bronchioles where gas exchange begins.

The movement of air into and out of the lungs, ensuring continuous gas exchange in the alveoli. This process involves inhalation, where air is drawn in due to lung expansion, and exhalation, where air is pushed out due to lung contraction.

Muscles that contract to increase the thoracic cavity volume, expanding the lungs and drawing air in. These include the diaphragm, external intercostals, sternocleidomastoid, and pectoralis minor.

Muscles that relax to decrease the thoracic cavity volume, pushing air out of the lungs. These include the diaphragm, external intercostals, rectus abdominis, and internal intercostals.

The exchange of gases across the respiratory membrane between the alveoli and pulmonary capillaries. Oxygen moves from the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli.

The exchange of gases between systemic capillaries and tissue cells. Oxygen diffuses from the blood into the cells, while carbon dioxide diffuses from the cells into the blood.

Normal, relaxed breathing that involves minimal muscular effort. It is characterized by a slow and regular rhythm.

Active, deep breathing that requires additional muscle effort. It is characterized by faster and deeper breaths, often used during exertion.

The measurement of lung volumes and capacities using a spirometer. This test assesses the health of the respiratory system by analyzing the amount of air inhaled, exhaled, and held in the lungs.