Transport in Animals Gastrovascular cavities –flatworms and cnidarians Nutrients and gases can move by processes such as diffusion and active transport.

Figure 42.1 Internal transport in the cnidarian Aurelia

Earthworm Closed Circulation Water Mouth Water Incurrent pore Sponge Hydra Nematode Gastrovas- cular cavity Gastrovas- cular cavity Gastrovascular cavity Osculum (excurrent opening) a. b.c. No Circulatory System Grasshopper Open Circulation Anus Hemolymph Heart Lateral hearts Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Open Circulatory systems Insects, other arthropods and most mollusks No distinction between blood and the interstitial fluid

Open Circulatory systems Hemolymph –name of general body fluid –directly bathes the internal organs System of sinuses Heart and body movements cause circulation

Open Circulatory systems Slower circulation sluggish animals BUT... –Insects are very active

Figure 42.2 Open and closed circulatory systems

Closed Circulatory Systems –Earthworms, squids, octopuses, and vertebrates Blood is confined to vessels and is distinct from interstitial fluid Consists of the heart, blood vessels and blood

Blood Plasma – about 55% of blood volume –90% water –inorganic salts (electrolytes), metabolites (vitamins, aa, glucose), wastes & hormones –proteins osmotic balance, viscosity buffers, transport lipids, antibodies, clotting factors (fibrinogen)

Plasma (92% water, 55% of whole blood) Formed elements Platelets and leukocytes (<1%) Red blood cells (erythrocytes) (45% of whole blood) Other solutes (1.5%) Electrolytes Nutrients Gases Regulatory substances Waste products Water (91.5%) Plasma proteins (7%) Albumin (54%) Globulins (38%) Fibrinogen (7%) All others (1%) Blood Plasma Red Blood Cells Plasma Red blood cells White blood cells Platelets 4 million–6 million/ mm 3 blood NeutrophilsEosinophils BasophilsLymphocytesMonocytes 3–8% Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0.5–1%20–25% 60–70%2–4% 150,000–300,000 mm 3 blood

Figure 42.14x Blood smear

Blood Cellular Elements: Red Blood Cells (Erythrocytes) –Most numerous (5-6 million in one cubic ml) –Transport oxygen & carbon dioxide

Blood Cellular Elements: White Blood Cells (Leukocytes) –Function in body’s defense –A cubic ml of blood has about 5,000 – 10,000 –in interstitial fluid or in the lymphatic system – where your body fights pathogens

4. Threads of fibrin trap erythrocytes and form a clot. 1. Vessel is damaged, exposing surrounding tissue to blood. 5. Once tissue damage is healed, the clot is dissolved. 3. Cascade of enzymatic reactions is triggered by platelets, plasma factors, and damaged tissue. 2. Platelets adhere and become sticky, forming a plug. Prothrombin Thrombin Fibrinogen Fibrin Cellular Elements: Platelets are cell fragments that pinch off from larger cells in the bone marrow -Function in the formation of blood clots Blood

Figure 42.16x Blood clot

Heart one atrium or two atria one or two ventricles

Heart one atrium or two atria –chambers that receive blood returning to the heart one or two ventricles –chambers that pump blood out of the heart.

Blood vessels Arteries –branch into arterioles Capillaries Veins –venules merge into veins

Blood vessels Arteries –branch into arterioles –carry blood away from heart Capillaries –materials are exchanged Veins –venules merge into veins –carry blood back toward heart

Blood Vessel Structure Walls of arteries or veins have three layers: –epithelium –smooth muscle with elastic fibers –connective tissue –Arteries have thicker walls than veins Capillaries only have the inner epithelium layer

Capillary Exchange Law of Continuity –blood flows slowly in capillaries because larger total cross-section –allows materials to be exchanged

Figure The interrelationship of blood flow velocity, cross-sectional area of blood vessels, and blood pressure

Capillary Exchange About 85% of the fluid that exits capillaries re-enters at the venule end.

Return of Blood to Heart Pressure too low in veins contraction of skeletal muscles move blood one-way valves in veins prevent backflow

Variation in Vertebrate Circulation FISH Two chambered heart and a single circuit of blood flow

Systemic capillaries Respiratory capillaries Gills Sinus venosus Ventricle Conus arteriosus Atrium Body Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Vertebrate Circulatory Systems

Variation in Vertebrate Circulation AMPHIBIAN Three chambered heart (two atria and one ventricle) and double circulation (two circuits of flow)

Lungs Body Pulmonary capillaries Systemic capillaries Ventricle Conus arteriosus Right atrium Pulmonary vein Pulmocutaneous artery Posterior vena cava Truncus arteriosus Aorta Carotid artery Systemic artery Left atrium Sinus venosus Ventricle Conus arteriosus Right atrium Left atrium a.b. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Amphibian Circulation

Variation in Vertebrate Circulation AMPHIBIAN Pulmonary circuit –blood is pumped to the lungs, where it is oxygenated and carried back to the left atrium Systemic circuit –blood is pumped to the rest of the body, where it gives up oxygen and is carried back to the right atrium

Variation in Vertebrate Circulation AMPHIBIAN Double circulation assures a vigorous flow of blood to the vital organs single ventricle --some mixing of oxygen- rich and oxygen-poor blood.

Variation in Vertebrate Circulation MAMMALS & BIRDS Have a four chambered heart and double circulation The left side of the heart handles oxygen- rich blood and the right side handles only oxygen-poor blood.

Head Body Lungs Systemic capillaries Pulmonary artery Pulmonary semilunar valve Inferior vena cava Superior vena cava Aorta Tricuspid valve Right ventricle Left ventricle Right atrium Pulmonary veins Left atrium Bicuspid mitral valve Systemic capillaries Pulmonary artery Superior vena cava Inferior vena cava Artery Pulmonary vein Aorta Respiratory capillaries a.b. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Mammalian or Bird Heart Valves prevent backflow of blood when the ventricles contract –Between each ventricle and atrium is an atrioventricular (AV) valve tricuspid and bicuspid (mitral) –At the exits of the heart are the semilunar valves

Head Body Lungs Systemic capillaries Pulmonary artery Pulmonary semilunar valve Inferior vena cava Superior vena cava Aorta Tricuspid valve Right ventricle Left ventricle Right atrium Pulmonary veins Left atrium Bicuspid mitral valve Systemic capillaries Pulmonary artery Superior vena cava Inferior vena cava Artery Pulmonary vein Aorta Respiratory capillaries a.b. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Q S Millivolts Seconds R P wave 1 sec The impulse begins at the SA node and travels to the AV node. 2. The impulse is delayed at the AV node. It then travels to the AV bundle. SA node (pacemaker) AV node AV bundle Left and right bundle branches Left and right bundle branches Purkinje fibers Left atrium Right atrium Purkinje fibers Interventri- cular septum AV bundle Interventricular septum AV AV bundle Internodal pathway 3. From the AV bundle, the impulse travels down the interventricular septum. 4. The impulse spreads to branches from the interven- tricular septum. 5. Finally reaching the Purkinje fibers, the impulse is distributed throughout the ventricles. T wave The control of heart rhythm

Cardiac Cycle a complete sequence of the heart contracting to pump blood, relaxing to fill with blood. total length is about 0.8 s –The contraction phase is called systole –The relaxation phase is called diastole

Figure 42.6 The cardiac cycle

Cuff Blood pressure gauge Stethoscope Cuff pressure: 150 mm Hg No sound: Artery closed 2. Cuff pressure: 120 mm Hg Pulse sound: Systolic pressure 3. Cuff pressure: 75 mm Hg Sound stops: Diastolic pressure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.