The mechanics of breathing
Diffusion: OXygen and carbon dioxide move across to alveolar cell membranes and then
into cell membranes of the capillaries around alveoli
Inhalation:During inhalation, chest cavity expansion causes lung expansion, creating
negative pressure and drawing air into the lungs.(inspiration)
Exhalation: Exhalation occurs when chest muscles relax, decreasing the chest cavity size,
compressing the lungs, and forcing air out.(expiration.)
Regulation of respiration
The respiratory center is in the medulla, located in the brainstem.This brain function
automatically controls inhalation by sending impulses to the phrenic nerve, which causes
contraction of the diaphragm and intercostal muscles.
Respiratory center: Nerves and a chemical control mechanism contribute to the
regulation of respirations.
Chemical regulation: Influenced by chemoreceptors located. in the carotid and aortic
bodies and in the medulla of the brain.
Chronic lung disease: develops when air is trapped in the alveoli due to a stiff, nonelastic
alveolar membrane , reducing oxygen and increasing carbon dioxide levels.
External respiration: External respiration occurs between alveoli and capillaries, with
oxygen passing from alveoli to capillaries during inhalation.
Internal respiration: Internal respiration involves oxygen diffusion from blood to cells
and carbon dioxide diffusion from cells to blood.
The pleura: Allows the lungs to hold pressure and promotes movement.
Impaired oxygenation
,Causes of impaired oxygenation
, Caring for patients with impaired oxygenation
Assessing respiratory status: color of skin and mucous membranes
Respiratory Assessment and Symptoms:
Dyspnea: Difficulty moving air in and out of the lungs (shortness of breath)
Exertional Dyspnea: SOB during light activity (e.g., walking to the bathroom)
Orthopneic Position: Sitting upright, leaning forward over a table; helps improve
inhalation in patients with impaired oxygenation
Signs of Respiratory Distress: Gasping ("air hunger"), grimacing, fear on the face
Productive Cough: Coughing up sputum or mucus from the lungs
Sputum Color and Possible Indications:
sputum: or mucus, from the lungs when coughing, it is referred to as a productive coug
Clear or White: May indicate a viral infection
Yellow or Green: Suggests a bacterial infection
Rust-Colored: Indicates blood; seen in pneumonia or tuberculosis
Gray or Black: Suggests inhalation of smoke or soot
Pink and Frothy: Indicates pulmonary edema (fluid + blood); life-threatening condition
Caring for patients with impaired oxygenation Assessing
Inspection:
Look for muscular retractions (between ribs, substernally, around neck) → Late sign of
hypoxia/hypoxemia
Watch for use of accessory muscles (neck, shoulders) → Indicates labored breathing