NR 324 Week 2 Upper Respiratory System

NR 324 Week 2 Upper Respiratory System

Student Name

Chamberlain University

NR-324 Adult Health I

Prof. Name:

Date

Structure and Function of the Respiratory System

Primary Function of the Respiratory System

The respiratory system’s central function is the facilitation of gas exchange, specifically the transfer of oxygen (O2) into the blood and carbon dioxide (CO2) out of the bloodstream into the atmosphere. It comprises the upper and lower respiratory tracts.

Anatomy of the Respiratory System

Upper Respiratory Tract

• Nose: Warms, filters, and humidifies inhaled air.
• Mouth
• Pharynx
• Epiglottis
• Larynx
• Trachea: Includes the carina, the site of tracheal bifurcation.

Lower Respiratory Tract

• Bronchi
• Bronchioles
• Alveolar ducts
• Alveoli: Main location for gas exchange with surrounding capillaries.
• Pores of Kohn: Facilitate air movement between alveoli and may allow bacterial spread.

Lung Lobes

• Right Lung: 3 lobes
• Left Lung: 2 lobes

Surfactant

• A lipoprotein that reduces alveolar surface tension, preventing alveolar collapse (atelectasis).

Pulmonary and Bronchial Circulation

Chest Wall Structures

• Ribs and sternum form the thoracic cage.
• Mediastinum houses the heart, aorta, and esophagus.
• Pleura: Parietal (lines chest cavity), visceral (covers lungs); intrapleural space contains 20–25 mL fluid.
• Diaphragm: Primary respiratory muscle innervated by the phrenic nerves (C3–C5).

Physiology of Respiration

Oxygen Transport

• Oxygen is carried in plasma (PaO2; 80–100 mmHg) and bound to hemoglobin (SaO2; >95%).

Mechanisms of Gas Exchange and Ventilation

• Gas exchange occurs via diffusion across the alveolar-capillary membrane.
• Inspiration is active (diaphragm and intercostals contract), while expiration is passive via elastic recoil.
• Compliance measures lung expandability; resistance reflects airflow impedance.

Regulation of Breathing

Central Control

• Medulla oblongata interprets chemical and mechanical signals.

Chemoreceptors

Mechanical Receptors

• Located in lungs and airways; include irritant, stretch (Hering-Breuer reflex), and juxtacapillary (J) receptors.

Respiratory Defense Mechanisms

• Air filtration
• Mucociliary clearance
• Cough reflex
• Bronchoconstriction
• Alveolar macrophages

Geriatric Considerations

• Structural: Reduced alveolar surface area and chest expansion
• Defense: Decreased immune function
• Regulation: Blunted response to O2/CO2 changes

Assessment of the Respiratory System

Health History and Subjective Data

• Past history: Respiratory illness, allergy, medications
• Risk exposure: Smoking, occupational exposure, travel
• Symptoms: Cough, sputum, dyspnea, sleep disturbances, pain, etc.
• Genetic history: Asthma, COPD, cystic fibrosis

Functional Patterns

Physical Examination

• Vital signs, oxygen saturation
• Inspection: Chest shape, movement, color
• Palpation: Tracheal alignment, chest expansion
• Percussion: Resonance over lungs, dullness over organs/muscle
• Auscultation: Breath sounds (normal/adventitious), voice sounds

Diagnostic Tests

References

Ignatavicius, D. D., Workman, M. L., Rebar, C. R., Heimgartner, N. M., & Hunte, C. N. (2021). Medical-Surgical Nursing: Concepts for Interprofessional Collaborative Care (10th ed.). Elsevier.

Lewis, S. L., Bucher, L., Heitkemper, M. M., Harding, M. M., Kwong, J., & Roberts, D. (2023). Medical-Surgical Nursing: Assessment and Management of Clinical Problems (11th ed.). Elsevier.

NR 324 Week 2 Upper Respiratory System

Smeltzer, S. C., Bare, B. G., Hinkle, J. L., & Cheever, K. H. (2020). Brunner & Suddarth’s Textbook of Medical-Surgical Nursing (14th ed.). Wolters Kluwer Health.