respiratory

Nasal Septum

Cartilage/bone wall dividing the nose into 2 nostrils.

Respiratory Membrane

Thin barrier (~0.5 µm) between alveolar air and capillary blood.

Mucosa Lining

Moist membrane lining nasal cavity; warms air, traps particles.

Pleura

Double membrane covering lungs and lining thoracic cavity.

Conchae

3 bony nasal ridges increasing surface area and air turbulence.

Pleural Fluid

Lubricating fluid in pleural space; reduces friction during breathing.

Paranasal Sinuses

Air spaces around nasal cavity; lighten skull, resonate speech, produce mucus.

Cardiac Notch

Indentation in left lung accommodating the heart.

Rhinitis

Inflammation of nasal/sinus lining; caused by allergens or viruses.

Diaphragm

Primary breathing muscle; contracts = inhalation.

Tidal Volume

Air exchanged per normal resting breath (~500 mL).

Uvula

Fleshy flap on soft palate; prevents food from entering nasal cavity during swallowing.

Residual Volume

Air remaining after maximum exhalation; prevents lung collapse.

Pharynx

The throat; shared by respiratory and digestive systems.

Vital Capacity

Maximum air consciously moved: TV + IRV + ERV.

Nasopharynx

Nasal section of pharynx; contains pharyngeal tonsil (adenoid).

Total Lung Capacity

Vital capacity + residual volume (~6L men, ~10% less women).

Oropharynx

Oral section of pharynx; contains palatine tonsils.

External Respiration

Gas exchange between alveoli and pulmonary blood in the lungs.

Laryngopharynx

Lowest pharynx section; contains epiglottis, opens to larynx + esophagus.

Internal Respiration

Gas exchange between blood and body tissues throughout the body.

Larynx

Voice box; connects pharynx to trachea; functions to open airway, divert food, produce sound.

VRG (Ventral Respiratory Group)

Pacemaker for quiet, regular breathing.

Epiglottis

Elastic cartilage flap; covers larynx during swallowing to prevent aspiration.

DRG (Dorsal Respiratory Group)

Collects sensory input, relays to VRG.

Thyroid Cartilage

Largest laryngeal cartilage; forms the Adam's apple.

Chemoreceptors

Sensors in aorta/carotid artery detecting CO2 and O2 levels.

Cricoid Cartilage

Ring-shaped cartilage attaching larynx to trachea.

Hyaline Cartilage

Structural cartilage keeping larynx and trachea from collapsing.

Bronchodilator

Medication relaxing airway smooth muscle; widens bronchi.

Cyanosis

Blue skin/lips from critically low blood oxygen.

Vocal Cords

Elastic tissue folds in larynx that vibrate to produce sound.

Surfactant

Prevents alveoli from sticking shut; deficient in premature infants.

Trachea (Windpipe)

~5 inch rigid tube with horseshoe cartilage rings leading to bronchi.

Granuloma

Immune cell cluster walling off infection (TB tubercles).

Bronchi

Two large tubes (R+L) branching from trachea into each lung.

BCG Vaccine

Bacille Calmette-Guérin; protects against tuberculosis.

Bronchioles

Small tubes branching from bronchi; lead to alveoli.

Alveolar Macrophage

Immune cell engulfing bacteria and particles inside alveoli.

Alveoli

Microscopic air sacs where O2/CO2 gas exchange occurs.

Respiratory Zone

Alveoli + capillaries; actual site of gas exchange.

Peak Flow Monitoring

Measures max exhalation speed; tracks asthma control.

Pulmonary Rehabilitation

Structured program improving function in chronic lung disease.

Asthma

Chronic inflammatory disease causing airway narrowing and difficulty breathing.

COPD (Chronic Obstructive Pulmonary Disease)

Progressive lung disease including chronic bronchitis and emphysema.

Tuberculosis (TB)

Bacterial infection primarily affecting the lungs, transmitted through the air.