Lecture One: Introduction to the Respiratory System and Review of Oxygenation

Vocabulary flashcards covering key concepts from the lecture notes on the respiratory system, oxygenation, and nursing care.

Ventilation (Pulmonary Ventilation)

The process of moving air in and out of the lungs (inspiration and expiration).

Gas exchange

Exchange of O2 and CO2 between air spaces in the lungs and the blood.

External respiration

Oxygen and carbon dioxide exchange between alveoli and pulmonary capillaries.

Internal respiration

O2 and CO2 exchange at the cellular level between blood and tissues.

Cilia

Hairlike structures in the respiratory tract that trap and move particles; aid defense.

Nose

Filters, warms, and moistens air; contains mucous membranes and hairs.

Nasal turbinates

Structures that humidify, warm, and filter inspired air.

Sinuses

Air-filled cavities draining into nasal passages to help humidify air.

Pharynx

Throat; passage for air and food; includes nasopharynx, oropharynx, and laryngopharynx.

Nasopharynx

Upper portion of the pharynx; includes Eustachian tubes.

Oropharynx

Behind the mouth; contains tonsils.

Laryngopharynx

Below oropharynx; connects to the larynx.

Larynx

Voice box; vibrates with exhaled air to produce speech; thyroid cartilage = Adam’s apple.

Thyroid cartilage

Largest cartilage of the larynx; forms the Adam’s apple.

Adam’s apple

Prominent part of the thyroid cartilage visible on the neck.

Epiglottis

Leaf-shaped structure that covers the airway during swallowing.

Cough reflex

Reflex triggered by irritants to clear the airway.

Trachea

Windpipe; 4–5 inches long; connects larynx to bronchi; lined with mucus and cilia.

Bronchi

Two main branches; right is wider and more vertical, left is more horizontal.

Bronchioles

Subdivisions of bronchi ending at terminal bronchioles and alveolar ducts.

Alveoli

300 million–1 billion grape-like sacs; site of gas exchange; surrounded by capillaries.

Surfactant

Lipid substance lining alveoli to prevent collapse; lowers surface tension.

Capillaries

Small blood vessels around alveoli where gas diffusion occurs.

Lungs

Paired, spongy organs; right lung has 3 lobes, left has 2 lobes.

Right lung lobes

Three lobes: superior, middle, and inferior.

Left lung lobes

Two lobes: superior and inferior (space for heart).

Apex

Top of the lung, about 1 inch above the first rib.

Base

Bottom of the lung resting on the diaphragm.

Pleura

Double-layered membrane surrounding the lungs; includes pleural fluid.

Visceral pleura

Covers the lungs.

Parietal pleura

Lines the thoracic cavity.

Pleural fluid

Lubricates pleural surfaces and reduces friction.

Pleural effusion

Accumulation of excess fluid in the pleural space.

Negative pressure

Subatmospheric pressure in the pleural space that keeps lungs inflated.

Diaphragm

Dome-shaped muscle; prime inspiratory muscle that flattens on contraction.

Inspiration

Active phase where the diaphragm contracts and thoracic volume increases.

Expiration

Passive phase where the diaphragm relaxes and thoracic volume decreases.

Oxygen transport

O2 carried mainly by hemoglobin (about 97%); remainder dissolved in plasma.

CO2 transport

CO2 returned from tissues to lungs via plasma and bicarbonate in RBCs.

Chemoreceptors

Sensors in carotid bodies and aorta that detect CO2, O2, and pH to regulate breathing.

Medulla and pons

Brainstem centers that regulate breathing rhythm and depth.

Blood pH 7.35–7.45

Normal blood pH range; CO2 acts as an acid influencing pH.

Acidosis

Increased CO2 or decreased HCO3- leading to acidity.

Alkalosis

Decreased CO2 or increased pH causing basicity.

Normal inspiration duration

Inspiration about 2 seconds; expiration about 3 seconds.

Room air composition

Atmospheric air ~21% O2.

Expired air composition

Air exhaled ~16% O2 and ~3.5% CO2.

Respiration rate (adult)

Adult 14–20 breaths/min.

Respiration rate (newborn)

Newborn 40–60 breaths/min.

Respiration rate (school-age)

School-age 20–24 breaths/min.

Respiration rate (teenagers)

Teenagers 20–22 breaths/min.

Cardiac Output

Normally ~5 L/min; affects O2 delivery to tissues.

Hematocrit/Hemoglobin ranges

Men: 40–54% Hct; Women: 37–47% Hct; affects O2 transport.

Hypoxia

Insufficient O2 anywhere in the body; early signs include restlessness and tachycardia.

Hypoventilation

Shallow, slow breathing leading to inadequate gas exchange and hypercapnia.

Hypoxemia

Low O2 level in the blood.

Hypoxia signs in pediatrics

Feeding difficulty, inspiratory stridor, nasal flaring, expiratory grunting, sternal retractions.

Eupnea

Normal, unlabored breathing.

Tachypnea

Rapid breathing rate.

Bradypnea

Slow breathing rate.

Apnea

Temporary cessation of breathing.

Cheyne-Stokes

Breathing pattern with cycles of apnea followed by deep breathing.

Hyperventilation

Increased rate/depth of breathing causing excessive CO2 loss.

Dyspnea

Difficulty breathing; may use accessory muscles.

Upper airway obstruction

Obstruction from tongue, food, or secretions.

Lower airway obstruction

Bronchospasms, thick secretions, or inflammation.

Oxygen therapy

Administration of supplemental O2; requires physician order.

Room air vs exhaled gas O2

Room air ~21% O2; exhaled air ~16% O2 and ~3.5% CO2.

Nasal cannula

O2 delivery device: 1–6 L/min, ~21–44% O2; comfortable for eating.

Simple face mask

O2 delivery device: 6–10 L/min, ~35–95% O2; may hinder eating.

Venturi mask

High-flow, precise O2 concentrations, commonly used in COPD.

Partial rebreather

Reservoir bag fills on exhalation; mixed inspired O2.

Non-rebreather

Reservoir bag never fully collapses; delivers 90–100% O2.

Face tent/hood

O2 delivery device for infants/children.

Oxygen tent

Tent providing cool mist/humidity; used in pediatrics.

Transtracheal catheter

Direct O2 delivery through the trachea for continuous oxygen.

CPAP

Continuous positive airway pressure; keeps alveoli open during breathing.

BiPAP

Bi-level positive airway pressure; different pressures for inhalation/exhalation.

Oral/nasal airway

Airway adjunct to prevent obstruction by the tongue or secretions.

Endotracheal tube

Short-term airway inserted through mouth or nose into trachea.

Tracheostomy

Surgical airway for long-term ventilatory support.

Laryngeal mask airway (LMA)

Airway device used commonly in anesthesia.

Nursing care with oxygen therapy

Assess skin integrity; perform oral care; reposition; monitor flow/humidifiers; suction as ordered; ensure sterile technique; position for lung expansion; encourage coughing, deep breathing, incentive spirometry, ambulation; provide comfort via rest and hydration.