Chapter 32 Pulmonology

External nares

The nostrils through which air enters the nasal cavity.

Nasal septum

Divides the nasal cavity into right and left chambers.

Turbinates

Three bony prominences on the lateral nasal wall causing air turbulence.

Meatus

A passageway between turbinates leading to the paranasal sinuses.

Goblet cells

Cells in the mucous membrane that produce mucus to trap particles.

Cilia in nasal cavity

Fingerlike projections moving mucus posteriorly toward the nasopharynx.

Kiesselbach's plexus

Rich supply of blood vessels in lower nasal septum that warms air.

Cranial Nerve I (CN-I)

Olfactory nerve passing through the cribriform plate for smell.

Pharynx divisions

Nasopharynx, oropharynx, and laryngopharynx.

Adenoids (pharyngeal tonsils)

Lymphoid tissue located in the nasopharynx.

Palatine and lingual tonsils

Lymphoid tissue located in the oropharynx.

Thyroid cartilage

The Adam's apple, forming part of the larynx structure.

Paired laryngeal cartilages

Arytenoid, corniculate, and cuneiform cartilages.

Glottic opening

The vocal cords and the space between them.

Epiglottis function

Tips backward during swallowing to divert food to the esophagus.

Trachea length and structure

Approximately 11 cm long with C-shaped cartilaginous rings.

Carina

The point where the trachea divides into mainstem bronchi; triggers coughing.

Right mainstem bronchus anatomy

Straighter continuation of trachea, making it prone to aspiration.

Bronchioles diameter

Approximately 1 mm thick, containing smooth muscle.

Terminal to respiratory bronchioles shift

Point after ~22 divisions where airway shifts to gas exchange.

Number of alveoli in lungs

Estimated 300 million in human lungs.

Alveolar type I cells

Thin cells forming the primary lining of the alveolar wall.

Surfactant source and function

Secreted by type II cells; decreases surface tension to keep alveoli open.

Alveolar macrophages

Immune cells that digest particles and bacteria in alveoli.

Physiologic shunt percentage

Approximately 2% of total pulmonary blood flow without gas exchange.

Lung lobe count

Right lung has 3 lobes; left lung has 2 lobes.

Visceral vs Parietal pleura

Visceral covers lungs (no nerves); parietal lines thorax (has nerves).

Bronchial arteries source

Branch from aorta to supply oxygenated blood to lung tissue.

Three processes of gas exchange

Ventilation, diffusion, and perfusion.

Phrenic nerve function

Arises from cervical spine to stimulate diaphragm contraction.

Inspiration mechanics

Active process; diaphragm flattens, chest expands, pressure drops 1-2 mmHg.

Accessory muscles of inspiration

Sternocleidomastoid, scalene, and abdominal wall muscles.

Pleural space pressure

4 to 8 mmHg below atmospheric pressure.

Expiration mechanics

Passive recoil of chest and diaphragm; pressure rises 1-2 mmHg above atmosphere.

Medium-sized bronchi in asthma

Offer greatest resistance to airflow during bronchospasm.

Lung compliance definition

Ease with which the chest wall and lungs expand with pressure changes.

Tidal volume value

Approximately 500 mL in a 70-kg adult.

Inspiratory reserve volume value

Approximately 3,000 mL in adult males.

Expiratory reserve volume value

Approximately 1,200 mL in adult males.

Residual volume value

Approximately 1,200 mL remaining in lungs at all times.

Vital capacity calculation

Inspiratory reserve + tidal volume + expiratory reserve (~4,800 mL).

Total lung capacity value

Approximately 6,000 mL in adult males.

Anatomical dead space volume

Approximately 150 mL in conducting airways.

Minute respiratory volume formula

Tidal volume × respiratory rate (~6,000 mL/min).

Primary ventilatory control center

Medulla in the lower brainstem.

Hering-Breuer reflex

Stretch receptor mechanism preventing lung overinflation.

Main chemical drive for ventilation

Arterial partial pressure of carbon dioxide (PaCO₂).

COPD primary hypoxic drive

Low arterial oxygen levels detected by aortic arch receptors.

Alveolar vs Capillary PO₂ gradient

Alveolar PO₂ is 104 mmHg; pulmonary capillary PO₂ is 40 mmHg.

Alveolar vs Capillary PCO₂ gradient

Pulmonary capillary PCO₂ is 45 mmHg; alveolar PCO₂ is 40 mmHg.

Respiratory membrane thickness

0.5 to 1.0 micrometer.

Oxygen transport methods in blood

>98% bound to hemoglobin;

Bohr effect

CO₂ binding to hemoglobin decreases O₂ affinity, releasing O₂ to tissues.

CO₂ transport percentages in blood

70% bicarbonate ion, 23% bound to hemoglobin, 7% dissolved in plasma.

Carbaminohemoglobin

Hemoglobin with CO₂ bound to amino acids on globin.

Haldane effect

Oxygenation of hemoglobin promotes release of CO₂.

Three conditions for lung perfusion

Adequate blood volume, intact pulmonary capillaries, efficient cardiac pumping.

Pulmonary vs Cellular respiration

Pulmonary occurs in lungs (alveoli/capillaries); cellular occurs in peripheral tissues.

What is the best way to describe the underlying pathophysiological change to the body's pulmonary system in light of a pulmonary embolism

Disturbance of alveolar perfusion within the lungs

cor pulmonale

What is the best way to describe the underlying pathophysiological change to the body's pulmonary system in light of a pulmonary embolism

Cheynes-Stokes

Periods of apnea and erratic breathing

Kussmaul’s respirations

Fast and labored breathing; indicative of DKA

Ataxic/Biot’s Respirations

Repeated episodes of gasping and apnea

Apneustic respirations

long, deep breaths that are stopped during the inspiratory phase and separated by periods of apnea

Central Neurogenic Hyperventilation

deep, rapid respirations caused by strokes or injury to the brainstem