BIOL 2200 Module 6: Respiratory Disorders

Paroxysmal nocturnal dyspnea (PND)

Awaking at night with dyspnea

Dyspnea

Breathing discomfort or shortness of breath.

Orthopnea

Dyspnea when laying down, as abdominal contents pressure the diaphragm

Hemoptysis

Expectoration of blood

Cyanosis

Bluish skin and mucous membrane coloring. Caused by increased deoxygenated hemoglobin in the blood

Clubbing

Bulbous enlargement at the end of a digit (finger, toe)

Hypercapnia (hypercarbia)

Elevated carbon dioxide in the bloodstream, from hypoventilation of the alveoli. Body cannot effectively eliminate CO₂

Hypoxemia

Reduced oxygenation of the blood. May be caused by defective oxygen diffusion from alveoli to the blood

V/Q mismatch

Imbalance between alveolar ventilation (V) and perfusion (Q)

How does high V/Q lead to hypoxemia?

Normal ventilation (V), inadequate perfusion (Q). Wasted ventilation, typically from pulmonary embolism

How does low V/Q lead to hypoxemia?

Inadequate ventilation (V), normal perfusion (Q). Known as “physiological right to left shunt,”

Anatomical right to left shunt

Where deoxygenated blood bypasses the lungs and directly enters systemic arterial circulation

Tetralogy of Fallot

Heart defect where pulmonary circulation is partially bypassed, causing oxygen-poor blood to pump throughout the body

Chest wall restriction