Circulation and Respiration Basic features Distribute nutrients throughout body Remove wastes from cellular activity Exchange gases Advanced features Defend against infection Cell communication – hormones

Why is a circulatory system necessary? Rate of diffusion limits effective transfer of nutrients. Fluid carries nutrient and dissolved gases to cells. Connects organs of exchange with the rest of the body Organs of exchange in animals Nutrients – stomach, intestines Gases – gills or lungs

Simple Distribution in Radiates Fluid filled channels distribute nutrients Branching Increases surface area Allows rapid diffusion to all cells

Open and Closed Circulatory Systems

Open Closed Blood and interstitial fluid the same - Hemolymph Exchange occurs at sinus Separate blood and interstitial fluid Exchange occurs at blood vessels

What Are the Features of Our Circulatory System? Fluid Vessels – tubes to carry fluid Pump to move fluid Valves to keep fluid moving in one direction Blood cells

Vertebrate Circulatory Schemes

Mammalian Circulatory System Pulmonary Loop Systemic Loop

Valve Structure of the Heart One way valves keep blood flowing in one direction

Cardiac Cycle

Cardiac Muscle Each cell is electrically connected to the next

Control of Heart Rhythm Coordinated contraction keeps blood flowing in one direction

Blood Vessels Arteries Veins Capillaries Blood moves by pressure from heart Veins Blood moves by action of valves and skeletal muscles Capillaries Many small branches to increase surface area

Structure of Blood Vessels

Vein vs. Artery Thin flexible wall One way valves Moved by skeletal muscles Thick more rigid wall No one way valves Moved by heart

Effects of Blood Vessel Branching As cross-sectional area increases blood velocity decreases As surface area increases blood pressure decreases

Veins

Blood Flow in Veins

Control of Blood Flow in Capillaries Blood can be diverted prevented from entering capillary net

Movement of Fluid in and Out of Capillaries

Blood Components of Blood

Blood Cells

Blood Clotting Warfarin

Gas Exchange

Gas Exchange in Aquatic Invertebrates

Gill Structure in Fish

Countercurrent flow Maximizes oxygen uptake Greatest difference in Oxygen content comes into contact with water

The human respiratory tract

Alveoli Structure 1

Alveoli Structure 2

Negative Pressure Breathing

Oxygen Loading and Unloading Hemoglobin in red blood cells carries oxygen and carbon dioxide

Hemoglobin Found in red blood cells Multiple protein complex with iron molecule Each hemoglobin binds to 4 oxygen or carbon dioxide molecules In general: High oxygen/low carbon dioxide – releases carbon dioxide and binds to oxygen Low oxygen/high carbon dioxide – releases oxygen and binds to carbon dioxide

Oxygen Dissociation Oxygen dissociation is greater at lower pH Metabolically active tissues have lower pH

Carbon Dioxide Exchange

Effect of respiratory poisons Carbon monoxide and cyanide Bind to hemoglobin more strongly than oxygen or carbon dioxide and don’t release Cells do not receive oxygen