Animal Form and Function Axolotl – salamander native to shallow ponds in Mexico. External Gills! Structure/Function Circulation and Gas Exchange Refer to pg 237-243 in Holtzclaw, Ch 42 in Campbell and media resources Also refer to AP Lab 10

LEARNING GOAL: HOW DO ANIMALS EXCHANGE GASES AND TRANSPORT THEM INTERNALLY? WHAT ARE VARIOUS STRUCTURE/FUNCTION EXAMPLES ACROSS THE ANIMAL KINGDOM?

Learning Intentions You must know: The circulatory vessels, heart chambers, and route of mammalian circulation. How red bloods cells (RBCs) demonstrate the relationship of structure to function. The general characteristics of a respiratory surface. The pathway a molecule of oxygen takes from the air until it is picked up by the hemoglobin of a red blood cell.

The circulatory vessels, heart chambers, and route of mammalian circulation. You must exchange gas, wastes, and nutrients at the cellular level by diffusion! Two solutions: 1) Keep all cells in contact with environment Gastrovascular Cavity 2) Move fluid around to tissues/cells for exchange Circulatory System

Gastrovascular Cavity

What are the three components of a Circulatory System?

What are the three components of a Circulatory System? Blood (Circulatory Fluid) Vessels (Tubes) Heart (Pump) Note differences in open vs closed. Open: blood and lymph are combined as hemolymph. Cavities called synuses. Arthropods and Molluscs. Closed: Blood in vessels. Blood separate from interstitial fluid. Annelids. Cephalopods, All Vertebrates.

In closed circulation you have: Arteries – Capillaries – Veins –

In closed circulation you have: Arteries – carry blood away from heart Thick, lots of smooth muscle Arterioles are smaller Capillaries – Gas/Nutrient/Waste Exchange Microscopic Walls are one-cell layer thick (significance?) Veins – carry blood back to the heart Have valves to prevent backflow Venules are smaller The heart has atria and ventricles

Try This! True or False? Capillary beds: Are the site of nutrient and oxygen delivery to tissues Have a total cross-sectional area much smaller than the total cross-sectional area of major arteries Join arterioles and venules

Try This! True or False? Capillary beds: Are the site of nutrient and oxygen delivery to tissues TRUE! Have a total cross-sectional area much smaller than the total cross-sectional area of major arteries FALSE! Join arterioles and venules TRUE!

Variations!

Variations!

Take a moment to read and understand the Path of Circulation on Page 239 in Holtzclaw

The Cardiac Cycle – Systole (contraction) and Diastole (Relaxation)

The Cardiac Cycle – Read Heart Rate on Page 240 in Holtzclaw

Blood Pressure: Read 42.2 on page 240 in Holtzclaw Analyze the graphs

Blood Pressure What happens to cross-sectional surface area, velocity, and pressure as you move through the circulatory system?

Activity: Measuring Blood Pressure! Experimental, not diagnostic!!!

Learning Intentions Do you know? The circulatory vessels, heart chambers, and route of mammalian circulation.

Learning Intentions You must know: The circulatory vessels, heart chambers, and route of mammalian circulation. How red bloods cells (RBCs) demonstrate the relationship of structure to function. The general characteristics of a respiratory surface. The pathway a molecule of oxygen takes from the air until it is picked up by the hemoglobin of a red blood cell.

Red Blood Cells: Structure/Function Biconcave disks Why? 250 million Hb/RBC No nuclei! No mitochondria! Produced from stem cells in bone marrow (as are all blood cells)

Red Blood Cells: Structure/Function Biconcave disks More surface area 250 mill Hb/RBC No nuclei! More room for Hb No mitochondria! O2 not used up Produced from stem cells in bone marrow (as are all blood cells)

THE GENERAL CHARACTERISTICS OF A RESPIRATORY SURFACE Respiratory surface (skin, gills, tracheae, lungs) are: Moist High surface area/volume ratio (folding, branching) Closely associated with vascular system of large animals

Breathing

Control Sense carbon dioxide and hydrogen ion Why hydrogen ion? Chemistry of carbon dioxide

Hemoglobin Globular protein Subunits? Where is it made? Can change its affinity for oxygen by slightly changing shape (Bohr Shift) Can carry oxygen, carbon dioxide, or hydrogen ions! Carbon dioxide usually carried as bicarbonate ions

To do: BioFlix!! Read Holtzclaw and do all activities in chapter 42 media resources (interactive animations) Do you know? The circulatory vessels, heart chambers, and route of mammalian circulation. How red bloods cells (RBCs) demonstrate the relationship of structure to function. The general characteristics of a respiratory surface. The pathway a molecule of oxygen takes from the air until it is picked up by the hemoglobin of a red blood cell.