RESPIRATION THE RESPIRATORY SYSTEM GAS EXCHANGE WITHIN THE LUNGS The Respiratory System - YouTube

RESPIRATION CO2 Carbon Dioxide: gas we breath out- exhale O2 Dioxygen: (Oxygen) gas we breath in- inhale CO2 Carbon Dioxide: gas we breath out- exhale IN (Nutrients + Oxygen) OUT (Energy + Carbon Dioxide + water) RESPIRATORY SYSTEM - RESPIRATORY TRACT - LUNGS - NASAL PASAGES - BRONCHIOLES - PHARYNX / LARYNX - AIR SACS (ALVEOLI) - TRACHEA - BRONCHI (that branch out into BRONCHIOLES)

RESPIRATION GOAL: extract oxygen from the air and expel carbon dioxide and other gases. PROCESS: inhale to fill up lungs. Lung volume increases, pressure decreases. Fluids (gas) always flow from high pressure to low pressure (Ch.3) and they are expelled. MECHANICS: intercostal muscles and diaphragm contract = lung volume increases with oxygen rich air. These muscles relax = lung volume decreases exhaling carbon dioxide Respiration-Ventilation 3D Medical Animation - YouTube

RESPIRATORY SYSTEM STRUCTURE DESCRIPTION FUNCTION NASAL PASSAGES Passages that open to the outside through the nostrils (nose) Filter air Warm and moisten air PHARYNX Section that serves as a common passageway between respiratory and digestive tracts Carries air towards trachea and food towards esophagus LARYNX Upper section of the trachea composed of cartilage and houses the vocal chords Carries air Produces sound TRACHEA 11cm in length and holds open to allow air into the bronchi Filters and purifies air Warms and moistens with mucus BRONCHI Tubes arising from the division of the trachea branches off once inside the lungs Carries air into the lungs LUNGS Spongy, elastic organs on each side of the heart, enclosed in the rib cage and composed of million of air sacs (called alveoli) Ensures gas exchange between body and external world

EXCHANGE OF GASES INHALATION EXHALATION Intercostal muscles and diaphragm contract Ribs rise and diaphragm descends, which increases the size of the rib cage Lung volume increases Air pressure inside the lung decreases. It becomes lower than the outside air pressure Oxygen-rich air from the outside flows into lungs until the pressure inside and outside the lungs is equal - Intercostal muscles and diaphragm relax Ribs descend and diaphragm rises, which decreases the size of the rib cage Lung volume decreases Air pressure inside the lung increases. It becomes greater than the outside air pressure Carbon dioxide-rich air inside the lungs flows outside until the pressure inside and outside the lungs is equal ALVEOLI TO CAPILLARY BLOOD VESSELS (DIFFUSION) CAPILLARY BLOOD TO ALVEOLI (DIFFUSION)