Fig. 42-3 Circulatory and Respiratory Systems Heart Heart Today’s topics: • (Finish Kidneys) Blood Hemolymph Interstitial Small branch vessels • Circulatory System fluid In each organ – Open vs closed – How the heart works Pores Dorsal vessel – Capillaries (main heart) • Respiration – Partial pressures of gasses Tubular heart Auxiliary hearts Ventral vessels – Lungs vs Gills – Other respiratory systems • Birds Open circulatory system Closed circulatory system • insects 8 April 2009 Gill capillaries Capillaries of Single Superior 7 Double vena cava head and forelimbs Loop Pulmonary Pulmonary Loop artery artery Capillaries Aorta of right lung 9 Capillaries Artery Gill of left lung circulation 3 2 3 Ventricle 4 Heart 11 Atrium Why do we Pulmonary Pulmonary vein 5 have two 1 vein Systemic different Right atrium 10 Left atrium Vein circulation loops? Right ventricle Left ventricle Inferior Aorta vena cava Capillaries of abdominal organs 8 Systemic capillaries and hind limbs Aorta Amphibians Reptiles Mammals and Birds 4-chambered heart Pulmonary artery Lung and skin capillaries Lung capillaries Lung capillaries 1. Right atrium 3. Left atrium Right Pulmocutaneous Pulmonary Pulmonary systemic circuit circuit circuit aorta Atrium (A) Atrium (A) A A A A Ventricle (V) V V Left V V Right Left Right Left systemic Right Left Systemic aorta Systemic Semilunar Semilunar circuit circuit valve valve Atrioventricular Systemic capillaries Systemic capillaries Systemic capillaries valve Atrioventricular valve Reptiles and Amphibians have 3 chambered hearts and different circulation patterns. 2. Right 4. Left ventricle ventricle 1 Fig. 42-8-3 2 Atrial systole; Semilunar ventricular Internal Pacemaker cells create heart rhythm valves diastole closed 1 Pacemaker 2 Signals are 3 Signals pass 4 Signals spread generates wave of delayed at to heart apex. throughout signals to contract. AV node. ventricles. 0.1 sec Semilunar AV valves 0.4 sec 0.3 sec open valves SA node open (pacemaker) 1 Atrial and ventricular ECG diastole AV valves closed 3 Ventricular systole; atrial diastole Sphincters relaxed Blood pressure causes fluid to leak out of capillaries Precapillary sphincters Thoroughfare channel Body tissue INTERSTITIAL FLUID Capillary Net fluid movement out Net fluid movement in Capillaries Arteriole Venule Direction of flow Osmosis brings (most) fluid back in Sphincters contracted Fig. 42-18-4 Red blood cell Collagen fibers Platelet Fibrin clot plug Platelet releases chemicals that make nearby platelets sticky Clotting factors from: Platelets Damaged cells Plasma (factors include calcium, vitamin K) Arteriole Venule Prothrombin Thrombin Fibrinogen Fibrin 5 !m 2 Respiratory System Partial pressures Terminal bronchiole • Atmospheric pressure = 760 mm Hg • Air is 21% O2 Alveoli • Partial pressure O2 = 0.21*760 = 160 mm Hg At top of Mt. Everest, atmospheric pressure is only 250. SEM Colorized 50 !m SEM 50 !m Therefore PO2 = ______ Fig. 42-22 Respiration in Aquatic Species Fluid flow through Oxygen-poor blood Anatomy of gills gill filament Oxygen-rich blood Gill arch Lamella Gill Gill filament arch organization Blood vessels Water flow Operculum Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange P (mm Hg) in water O2 150 120 90 60 30 Gill filaments Net diffu- 140 110 80 50 20 sion of O2 from water P (mm Hg) in blood to blood O2 Fig. 42-23 Fig. 42-26 Air sacs Tracheae Air Air Anterior air sacs Trachea External Posterior opening Tracheoles Mitochondria Muscle fiber air sacs Lungs Lungs Body cell Air Tracheole Air tubes sac (parabronchi) 1 mm in lung INHALATION EXHALATION Air sacs fill Air sacs empty; lungs fill Trachea Air Body wall 2.5 !m 3.