Anatomy and Physiology of the Respiratory System Flashcards

A set of 50 vocabulary flashcards covering the anatomy, physiology, and common pathologies of the pulmonary system, including geriatric and pediatric considerations.

DNA (in the body)

A meter of it is packed into every cell; if all of it in the body were formed into a single strand, it would stretch ten billion miles, beyond Pluto.

Lungs (surface area)

If smoothed out, these organs would cover the area of a tennis court.

Blood vessels (total length)

The total length of these within the body would stretch two and a half times around the Earth.

Respiratory system

A system consisting of two lungs, conducting airways, and associated blood vessels.

Inhalation (Inspiration)

The process during ventilation where air is taken into the body and travels through respiratory passages to the lungs.

Exhalation (Expiration)

The process by which $CO_2$ is expelled from the body.

Perfusion

The process where oxygen ($O_2$) in the lungs replaces carbon dioxide ($CO_2$) in the blood at the level of the alveoli.

Gas exchange

The major function of the respiratory system, occurring by diffusion through respiratory membranes.

Ventilation

The delivery system that presents oxygen-rich air to the alveoli; the process by which air flows into and out of the gas-exchange airways.

Oxygenation

The process of delivering $O_2$ from the alveoli to the tissues in order to maintain cellular activity.

Pulmonary alveoli

Grapelike clusters of air-filled sacs (about 300 million in adult lungs) at the ends of respiratory passages where gas exchange occurs.

Diffusion

The passage of gas molecules through respiratory membranes during the transfer of $O_2$ to blood and $CO_2$ from blood.

Asthma

A chronic inflammatory disorder of the bronchial mucosa causing bronchial hyperresponsiveness, mucosal edema, and reversible airway constriction.

Chronic Obstructive Pulmonary Disease (COPD)

A collection of lung diseases causing breathing problems and obstructed airflow, including phenotypes of chronic bronchitis and emphysema.

Asthma-COPD Overlap Syndrome (ACOS)

A phenotype of chronic respiratory disease where a patient experiences the clinical symptoms of both asthma and COPD simultaneously.

Genetically induced asthma

Sensitivity to specific external allergens including pollen, animal dander, house dust, mold, or food additives containing sulfites.

Environmentally induced asthma

A reaction to internal, nonallergenic factors such as respiratory tract infections, pollutants, emotional stress, or temperature variations.

Pulmonary edema

The presence of excess water in the lung caused by disturbances of capillary hydrostatic pressure, oncotic pressure, or permeability.

Left-sided heart failure

A common cause of pulmonary edema which increases the hydrostatic pressure in the pulmonary circulation.

Dyspnea on exertion

An early sign of pulmonary edema characterized by shortness of breath during physical activity.

Paroxysmal nocturnal dyspnea

Sudden shortness of breath occurring at night, often associated with early-stage pulmonary edema.

Orthopnea

A condition where the patient experiences difficulty breathing while lying flat.

Atelectasis

The complete or partial collapse of a lung or lung lobe that occurs when alveoli become deflated or filled with fluid.

Hypoxemia

A below-normal level of oxygen in the blood (specifically the arteries), caused by decreased inspired oxygen, hypoventilation, or diffusion abnormalities.

Clubbing

A physical change in the fingertips associated with diseases that disrupt normal pulmonary circulation and cause chronic hypoxemia.

Hypercapnia

A buildup of carbon dioxide in the bloodstream, often affecting people with chronic obstructive pulmonary disease.

Symptoms of hypercapnia

Include labored or shallow breathing, wheezing, altered consciousness, fever, flushed skin, sweating, fatigue, and headache.

Respiratory depression

A significant risk factor associated with opioid overdose, potentially leading to hypercapnia respiratory failure.

Abnormal breathing

Breathing patterns such as Kussmaul, Cheyne-Stokes, or gasping, used to decrease respiratory work and ease ventilation.

Irritant receptors

Neuroreceptors in the lungs that sense the need to expel unwanted substances.

Stretch receptors

Neuroreceptors in the lungs that monitor lung volume and lung expansion.

J-receptors

Neuroreceptors in the lungs that sense alveolar size.

Mechanics of breathing

The interaction of forces involving respiratory muscles, alveolar surface tension, elastic properties of lungs, and airflow resistance.

Chemoreceptors

Receptors in the circulatory system and brainstem that monitor pH in cerebrospinal fluid and the $PaO_2$ and $PaCO_2$ levels in arterial blood.

Respiratory center

The area in the brainstem that controls ventilation, largely on an involuntary basis.

Airway caliber

The diameter of the airways, adjusted by the sympathetic and parasympathetic divisions of the ANS through bronchial smooth muscle control.

Vasoactive mediators

Substances such as nitric oxide, endothelin, prostaglandins, and bradykinin that influence pulmonary vasodilation and vasoconstriction.

Acinus

The functional unit of the lung comprising structures beyond the sixteenth division, including respiratory bronchioles, alveolar ducts, and alveoli.

Lung bases

The areas of the lungs where ventilation and perfusion are greatest because the alveoli are more compliant and gravity increases blood flow.

$\alpha_1$-adrenergic receptors

Receptors through which sympathetic stimulation generally promotes pulmonary vasoconstriction.

Hypoxic pulmonary vasoconstriction

A mechanism where hypoxia causes pulmonary vessels to constrict, redirecting blood away from poorly ventilated alveoli toward better-ventilated areas.

Infant pulmonary anatomy

Characteristics include narrower airways than adults and compliant chest walls, making them more prone to obstruction and increased work of breathing.

Blunted ventilatory response

An immature reaction to hypoxia and hypercapnia seen in newborns due to underdeveloped respiratory control centers.

Stridor

A high-pitched sound, usually heard on inspiration, caused by an obstruction or narrowing in a child's upper airway.

Croup

An upper airway infection characterized by a barking cough and swelling around the larynx, trachea, and bronchi.

Acute epiglottitis

A life-threatening condition occurring when the small cartilage lid covering the windpipe swells, blocking air flow.

Peritonsillar abscess

The most common deep infection of the head and neck, often characterized by a "hot potato" voice and trismus.

Cyanosis

A bluish discoloration of the skin and mucous membranes caused by a concentration of deoxygenated hemoglobin $\geq 5\,g/dL$.

Polycythemia

A condition involving an increased amount of total hemoglobin, which can contribute to the development of cyanosis.

V/Q matching

The optimization of ventilation and perfusion to ensure efficient gas exchange in the lungs.