Respiratory System Overview

Bronchioles

  • Function: Oxygen intake and Carbon dioxide release through Ventilation.
  • Other functions: Heating/cooling, filtering, humidifying air, sense of smell, sound production, gas exchange.

Pharynx

  • Muscular part of throat, carries air to respiratory tract and food to digestive tract.
  • Divided into three sections: Nasopharynx, Oropharynx, Laryngopharynx.

Larynx

  • Known as voice box, located between pharynx and trachea.
  • Functions in phonation (sound production).
  • Contains vocal cords, produces sound by vibrational contact with air.
  • Glottis: opening between vocal cords, involved in sound manipulation.

Paranasal Sinuses

  • Located within nasal cavities.
  • Function: resonating chambers for voice, decrease skull weight.

Respiratory Tract Overview

  • Upper Respiratory Tract: Nasal Cavity, Pharynx, Larynx.
  • Lower Respiratory Tract: Trachea, Bronchi, Alveoli.

Epithelial Lining Functions

  • Cilia sweep mucus and particles toward the outside.
  • Goblet cells produce mucus to trap particles.

Larynx Anatomy

  • Cartilages: Thyroid (Adam's apple), Cricoid (landmark for procedures).
  • Epiglottis: Covers the larynx during swallowing to prevent food entering the airway.

Trachea

  • Known as the windpipe, connects larynx to lungs.
  • Supported by C-shaped cartilaginous rings to prevent collapse.
  • Divides into primary bronchi entering each lung (right bronchus larger).

Lungs

  • Gas diffusion occurs here, enclosed in thoracic cavity.
  • Primary bronchi split into smaller bronchi, then bronchioles, leading to alveoli.
  • Alveoli surrounded by blood capillaries for gas exchange.

Gas Exchange

  • Process: Oxygen absorbed into blood from alveoli; Carbon dioxide expelled from blood into alveoli.
  • Surfactant: Phospholipid covering alveoli, decreases surface tension.

Types of Respiration

  • External Respiration: Gas exchange in alveoli.
  • Internal Respiration: Gas exchange at capillary beds.

Ventilation vs. Respiration

  • Ventilation: Physical process of air movement (diaphragm contraction/relaxation).
  • Respiration: Chemical process of gas exchange.

Diaphragm and Breathing

  • Inspiration: Diaphragm contracts, thoracic cavity expands, pressure decreases, air moves in.
  • Expiration: Diaphragm relaxes, thoracic cavity contracts, pressure increases, air moves out.