Respiratory system

Upper Respiratory Tract include

Nose & Nasal Cavity, Sinuses, and Pharynx (Throat)

Nose & Nasal Cavity

Filters, warms, and humidifies air.

Sinuses

Lightens skull, produces mucus, resonance for speech.

Pharynx (Throat)

Passageway for air & food.

Lower Respiratory Tract include

Larynx (Voice Box), Trachea (Windpipe), Bronchi & Bronchioles

Larynx (Voice Box)

Protects airway, voice production.

Trachea (Windpipe)

Conducts air to bronchi.

Bronchi & Bronchioles

Distribute air into lungs.

Lungs & Alveoli

Gas exchange occurs in alveoli.

Conduction Portion (Air Passageways Only)

Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles.

Respiratory Portion (Gas Exchange)

Respiratory bronchioles → Alveolar ducts → Alveoli.

Pseudostratified Ciliated Columnar Epithelium (Most of Tract)

Moves mucus & debris.

Stratified Squamous Epithelium (Pharynx & Vocal Cords)

Protection from abrasion.

Simple Squamous Epithelium (Alveoli)

Allows gas exchange.

Goblet Cells & Mucous Glands

Produce mucus to trap debris.

Cilia

Move mucus upward to pharynx to be swallowed.

Alveolar Macrophages

Remove small particles that reach alveoli.

NasopharynxEpithelium is

Pseudostratified ciliated columnar (only air passes).

Oropharynx Epithelium is

Stratified squamous (air & food pass).

Laryngopharynx Epithelium is

Stratified squamous (air & food pass).

Thyroid Cartilage

"Adam's apple," protects vocal cords.

Cricoid Cartilage

Ring-shaped, supports larynx.

Epiglottis

Prevents food from entering airway.

Arytenoid, Corniculate, & Cuneiform Cartilages

Assist with vocal cord movement.

Trachea (Windpipe)

Cartilage rings keep airway open.

Primary (Main) Bronchi

One per lung.

Secondary (Lobar) Bronchi

One per lung lobe.

Tertiary (Segmental) Bronchi

Supply bronchopulmonary segments.

True Vocal Folds

Vibrate to produce sound.

False Vocal Folds (Vestibular Folds)

Protect true vocal cords, no sound production.

Right Lung has

3 lobes (Superior, Middle, Inferior) and Horizontal & Oblique Fissures.

Left Lung has

2 lobes (Superior, Inferior) and Oblique Fissure.

Left Lung Smaller

Due to heart position (Cardiac Notch).

Type I Alveolar Cells

Simple squamous, gas exchange.

Type II Alveolar Cells

Produce surfactant (reduces surface tension, prevents alveolar collapse).

Primary Muscle of Diaphragm

(contracts = inhalation, relaxes = exhalation).

Inhalation

External intercostals, sternocleidomastoid, pectoralis minor.

Exhalation

Internal intercostals, abdominal muscles (forced exhalation).

Quiet Breathing (Eupnea)

Passive exhalation.

Forced Breathing (Hyperpnea)

Active exhalation using muscles.

Aging Effects

Elasticity decreases, reducing lung function and Alveoli deterioration, less gas exchange.

Asthma

Bronchoconstriction due to inflammation.

Chronic Obstructive Pulmonary Disease (COPD)

Chronic airway obstruction (Emphysema + Chronic Bronchitis).

Pneumonia

Infection causes alveoli to fill with fluid.

Pulmonary Fibrosis

Scarring reduces lung elasticity.

Lung Cancer

Uncontrolled cell growth in lung tissue.