Respiration Review Air bulk flow cuased by lungs

Respiration Review Air bulk flow cuased by lungs From air in lungs to red blood cells Blood bulk flow caused by heart From red blood cells to body cells

Bulk Flow: Air into Lungs • Diaphragm allows inspiration • Intercostal muscles allow forceful expiration

Diffusion • The protein HEMOGLOBIN binds the oxygen tightly so that no diffusion occurs until the r. b. c. is near O 2 deprived body cells

Bulk Flow: O 2 to Body Cells

The Components of Blood • Red Blood Cells: – Transport O 2 • White Blood Cells: – Protect the cells from infection/invasion • Platelets: – Clot the blood to prevent it from spilling out when a rupture of the fluid conduit occurs • Plasma: – Glucose, hormones, etc. suspended in a viscuous goo

Red Blood Cells • The protein “Hemoglobin” binds to O 2 • Binds CO 2 more strongly than O 2 • Binds CO much more strongly than CO 2 (Carbon Monoxide Poisoning) • Contain no nucleus! • Recycled every week or so

White Blood Cells • Slip in between blood vessel cells • Recognize and destroy foreign matter

Platelets • Aid in blood clotting • Recognize micro tears in blood conduits and bind together to form a clot

How blood is transported • Arteries: – Structures that carry blood away from the heart – Rigid to take pressure of blood right out of heart • Capillaries: – Very narrow and thin tubes between arteries and veins where diffusion occurs – Can close down or open up to regulate blood flow (e. g. stress, eating, etc. . . ) • Veins: – Loosen to expand more (controlled by smooth muscles) – Store great quantities of blood

Another Look at Blood Vessels

How Blood Circulates: The Heart

The Heart • Contraction of ventricals – Larger of heart chambers – Takes blood in from the atria – Pumps blood out to the body • Contraction of atria – Smaller chambers – Takes blood in from body – Pumps blood into the ventricals • Coordinated beating of atria then ventricals

Cardiac Cycle • Right Ventrical pumps de-oxygenated blood to lungs • Left Ventrical pumps oxygenated blood to the body cells • Valves prevent backflow of blood

Coordination of the Beating • Heart cells naturally beat slowly if ATP is present • If there was no coordination, the heart cells would all beat randomly (fibrillation) • Coordinated beating occurs because a group of cells (the pacemaker cells) send nerve impulses to the other cells stimulating them to beat at the right time • Atria beat from top down, pause, Ventricals beat from bottom up

The Cardio-Pulmonary System