Chapter 17: Respiratory System

Respiratory system

A system of organs responsible for gas exchange—bringing in oxygen and removing carbon dioxide.

Nasal cavity

The interior of the nose that filters, warms, and moistens incoming air.

Pharynx

A muscular tube (throat) that serves as a passageway for both air and food.

Nasopharynx

The upper part of the pharynx, connecting with the nasal cavity.

Oropharynx

The middle part of the pharynx behind the oral cavity.

Laryngopharynx

The lower part of the pharynx leading to the larynx and esophagus.

Larynx

The voice box; contains the vocal cords and routes air and food into proper channels.

Epiglottis

A flap of cartilage that closes over the trachea during swallowing to prevent choking.

Trachea

The windpipe; a tube that connects the larynx to the bronchi.

Bronchi

The two main branches of the trachea that carry air into the lungs.

Bronchioles

Smaller branches of the bronchi within the lungs.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Lungs

Two spongy organs responsible for breathing and gas exchange.

Right lung

Divided into three lobes: superior, middle, and inferior.

Left lung

Divided into two lobes: superior and inferior, with a cardiac notch for the heart.

Pleura

A double-layered membrane surrounding each lung.

Parietal pleura

The outer layer of the pleura lining the thoracic cavity.

Visceral pleura

The inner layer of the pleura covering the lungs.

Pleural cavity

The space between the pleural layers containing fluid to reduce friction.

Diaphragm

A dome-shaped muscle that contracts to allow inhalation and relaxes for exhalation.

Inhalation (inspiration)

The process of drawing air into the lungs.

Exhalation (expiration)

The process of expelling air from the lungs.

External respiration

Gas exchange between the alveoli and the blood in pulmonary capillaries.

Internal respiration

Gas exchange between the blood and body cells.

Cellular respiration

The use of oxygen by cells to produce energy, with carbon dioxide as a byproduct.

Respiratory rate

The number of breaths taken per minute.

Tidal volume

The amount of air inhaled or exhaled during normal breathing.

Vital capacity

The maximum amount of air a person can exhale after maximum inhalation.

Hypoxia

A condition in which there is an insufficient amount of oxygen in the tissues.

Hypercapnia

An elevated level of carbon dioxide in the blood.

Dyspnea

Difficulty or labored breathing.

Apnea

Temporary cessation of breathing.

Orthopnea

Difficulty breathing while lying down.

Tachypnea

Rapid breathing.

Bradypnea

Slow breathing.

Asthma

A chronic respiratory condition characterized by airway inflammation and narrowing.

Bronchitis

Inflammation of the bronchial tubes, often due to infection or irritants.

Emphysema

A chronic condition where alveoli are damaged, reducing surface area for gas exchange.

Chronic obstructive pulmonary disease (COPD)

A group of chronic lung diseases that block airflow and make breathing difficult.

Pneumonia

An infection that inflames the air sacs in the lungs, which may fill with fluid.

Tuberculosis (TB)

A bacterial infection that mainly affects the lungs and is highly contagious.

Lung cancer

A malignant tumor that originates in the tissues of the lungs.

Pulmonary embolism

A blockage in a pulmonary artery caused by a blood clot.

Respiratory distress syndrome (RDS)

A condition in newborns or adults where lungs are unable to function properly.

Ventilator

A machine that helps a person breathe when they are unable to do so on their own.

inspiratory reserve volume

the amount of air someone can take in over the tidal volume (deep breath)

expiratory reserve volume

the amount of air someone can exhale over the normal tidal volume (deep exhale)

vital lung capacity

total between TV, IRV, and ERV

residual volume

volume that cannot be exhaled from lungs

functional residual capacity

ERV + RV

total lung capacity

TV, IRV, ERV, and RV total