Respiratory System

Tracheal System in Insects Tracheal system Branched air tubes Air sacs spiracle

Path of air 1.pharynx 2.Larynx 3.Trachea 4.Bronchi 5.Bronchioles 6.Alveoli (air sacs)

Alveolus/alveoli 300 million/lung Surrounded by capillary bed coming from right atria  pulmonary arteries (low O 2 )-why?! 1 cell thick walls….why?!

Ventilation V Gas Exchange V Cellular Respiration 2F%2Fwww.youtube.com%2Fwatch%3Fv%3DnJuFmyXeHkA&has_veri fied=1 2F%2Fwww.youtube.com%2Fwatch%3Fv%3DnJuFmyXeHkA&has_veri fied=1

Gas Exchange Uptake of O 2 from environment and discharge of CO 2 Involves lungs and capillary beds

Alveoli Details Large S.A Flat, single cell Moist lining Nearby capillary bed

Gas Exchange cont. Atmosphere =21% O 2 by volume O 2 and CO 2 move into and out of lungs via PASSIVE transport (we need a concentration gradient) Lung surface=thin, folded, moist, and branched to maximize gas exchange

Gas Exchange cont. Rate of diffusion is proportional to surface area and the inverse of distance needed to travel…see size of lung and distance to capillary bed

Ventilation Act of breathing Increase flow of respiratory medium (source of O 2 ) over respiratory surface Ex: human breathing EX: fish and gills

Why do we need ventilation? Creates a concentration gradient for O 2 and CO 2 O 2 needed for aerobic respiration O 2 from lungs to blood CO 2 from blood to lungs Cycles lung air with atmosphere

Ventilation Muscles surrounding lungs include Diaphragm, abs, intercostal muscles Lungs located in thoracic cavity Lungs “open” to atmosphere via trachea

Pressure V Volume in lungs Inverse relationship

Inspiration V Expiration

Inspiration Inside lungs, volume increases so pressure….? Creates a partial vacuum inside of the lung Air that comes in via your mouth or nasal passageway counteracts the partial vacuum The air fills your alveoli

Inspiration Interactive chapter23/animation__alveolar_pressure_changes_during_inspiratio n_and_expiration.html chapter23/animation__alveolar_pressure_changes_during_inspiratio n_and_expiration.html

Blood’s Role Hemoglobin Structure

4 O 2 = saturated

Myoglobin Heme protein found in muscle that stores 1 oxygen molecules Releases the oxygen as needed

Oxygen Dissociation Curve X-axis= partial pressure of oxygen Y-axis= % Oxygen saturation in hemoglobin Oxygen’s partial pressure increases as more Oxygen binds to hemoglobin and myoglobin (changes shape so O 2 binds easier)

Fetuses need more oxygen than adults

Bohr Shift When CO 2 binds to hemoglobin, O 2 is released

Exercise Medulla oblongata controls the diaphragm and intercostal muscles Increase in CO 2 = decrease in pH in blood=more nerve impulses=increased ventilation to get more O 2

Asthma Airways=inflamed, produce extra mucous

Smoking Stiffens cilia=mucous accumulates Emphysema= alveoli walls loose elasticity so air gets stuck

High Altitude Air pressure changes Increase RBC Increase capillaries in lungs and muscles Increase lung size Increase myoglobin