Respiratory System Overview

Respiratory System

• Breath represents life, marking the beginning and end of human experience
• Breathing is necessary for ATP synthesis, a process that fuels the majority of metabolic processes
• The respiratory system is a conduit and exchange region for oxygen and carbon dioxide
• The respiratory system components are mainly tubes that facilitate air delivery to the lungs, where gas exchange occurs

Respiratory System Function

• Oxygen uptake and carbon dioxide removal for metabolic processes.
• Communication (speech)
• Olfaction (smell)
• Acid-base balance regulation
• Blood pressure regulation
• Expulsion of abdominal contents (e.g., coughing)

Main Respiratory System Functions

• Gas exchange (oxygen and carbon dioxide exchange)
• Communication (voice production)
• Olfaction (smell)
• Acid-base balance regulation
• Blood pressure regulation
• Expulsion of abdominal contents

Respiratory Tract

• Upper Respiratory Tract: nose, pharynx, larynx
• Lower Respiratory Tract: trachea, bronchi, bronchioles, alveoli

Conducting Division

• Structures that conduct air, but don't exchange gases (e.g., nose, trachea, bronchi)
• Walls are too thick to allow rapid gas exchange.

Respiratory Division

• Structures where gas exchange occurs (e.g., alveoli)
• Millions of small, microscopic air sacs
• Exchange of gases with the circulatory system through the walls of the alveoli.

Nose (Nasus)

• Warms, cleanses, humidifies inhaled air
• Detects odors
• Resonating chamber that amplifies the voice
• Extends from nostrils to posterior nasal apertures (choanae)
• Supported by bone and cartilage

Pharynx (Throat)

• Funnel-shaped muscular passageway
• Common passageway for air and food
• Divided into three regions: nasopharynx, oropharynx, and laryngopharynx

Larynx (Voice Box)

• Cartilaginous structure located between the pharynx and trachea.
• It protects the trachea from food, prevents choking, and produces sound through vocal cord vibrations (phonation)

Trachea and Bronchi

• The trachea ("windpipe") is a tube held open by cartilage rings, and situated in front of the esophagus.
• The trachea branches into two main bronchi.
• Bronchi subdivide into smaller and smaller tubes (bronchioles), ending in air sacs (alveoli)
• The bronchioles, bronchi, and trachea facilitate air transport to and from the lungs.

Lungs

• Paired cone-shaped organs in the thoracic cavity, enclosed in the pleura.
• Facies diaphragmatica, costalis, and mediastinalis surfaces (diaphragm facing, ribs facing, and the middle facing)
• The root of the lung consists of the blood vessels, airways, nerves that enter/exit the lungs at the hilum region
• The lungs have lobes (superior, middle, and inferior lobes), separated by fissures.

Pleura

• Membrane that encloses and protects the lungs.
• Two layers: visceral (inner) and parietal (outer) pleura
• Pleural cavity is the space between the layers, containing fluid to reduce friction during lung expansion.