UNIFYING CONCEPTS OF ANIMAL CIRCULATION Every organism must exchange materials with its environment, relying upon diffusion, the spontaneous movement of molecules from an area of higher concentration to an area of lower concentration, and a circulatory system, which facilitates the exchange of materials for all but the simplest animals. 6 Open and Closed Circulatory Systems Circulatory systems typically consist of a central pump, vascular system, and circulating fluid. 7 Open and Closed Circulatory Systems 8 Open and Closed Circulatory Systems 9 In an open circulatory system, In a closed circulatory system, blood the heart pumps blood into large open-ended vessels and fluid circulates freely among cells. stays within a set of tubes and is distinct from the interstitial fluid, the fluid that fills the spaces around cells. Open circulatory systems are found in many invertebrates, including arthropods and Closed circulatory systems are found in many invertebrates, including earthworms and octopuses, and most molluscs. vertebrates.
Figure 23.1 10 Figure 23.1a 11 Circulating fluid Tubular heart Artery ( -rich blood) Arteriole Interstitial fluid Venule Circulating fluid Tubular heart (a) Open circulatory system Atrium Artery Ventricle ( -poor blood) (b) Closed circulatory system Vein (a) Open circulatory system Figure 23.1b 12 Open and Closed Circulatory Systems 13 Artery ( -rich blood) Arteriole Interstitial fluid Atrium Artery Ventricle ( -poor blood) (b) Closed circulatory system Venule Vein The cardiovascular system of vertebrates consists of the heart and blood vessels. In the heart, the atrium receives blood and the ventricle pumps blood away from the heart.
Open and Closed Circulatory Systems Blood is confined to three main types of blood vessels: 1. Arteries carry blood away from the heart into smaller arterioles as they approach the organs. 2. are the site of exchange between blood and interstitial fluid. 3. Venules collect blood from the capillaries and converge to form veins, which return blood back to the heart. 14 UNIFYING CONCEPTS OF ANIMAL RESPIRATION Cellular respiration uses oxygen and glucose and produces water, carbon dioxide, and energy in the form of ATP. 98 UNIFYING CONCEPTS OF ANIMAL RESPIRATION 99 Figure 23.UN01 100 Cells using cellular respiration need a steady supply of oxygen and must continuously dispose of. Environment Cell The respiratory system promotes this gas exchange. C 6 H 12 O 6 6 6 6 H 2 O ATP Glucose Oxygen Cellular respiration Carbon dioxide Water Energy
101 The Structure and Function of Surfaces The Structure and Function of Surfaces 102 Animals can get oxygen from the atmosphere, which contains about 21% oxygen, and bodies of water, which contain about 3 5% oxygen. Gas exchange occurs at the respiratory, which must be large enough to take up oxygen for every cell in the body and adapted to the lifestyle of the organism. The Structure and Function of Surfaces 103 Figure 23.15 104 Moist skin is used as a respiratory in earthworms. In aquatic environments, the main respiratory s are skin and extensions of the body called gills. Cross section of respiratory (the skin covering the body) O2 Body (gill) (a) Skin (b) Gills
Figure 23.15a 105 Figure 23.15b 106 Cross section of respiratory (the skin covering the body) Body (gill) (a) Skin (b) Gills The Structure and Function of Surfaces 107 The Structure and Function of Surfaces 108 In most land-dwelling animals, the respiratory s are folded into the body and open to the air only through narrow tubes. Insects breathe using a tracheal system, an extensive network of internal tubes called tracheae that branch throughout the body and extend to nearly every cell.
Figure 23.16 109 Figure 23.16a 110 Body (tracheae) Body (within lung) Body (tracheae) (a) Tracheae Body cells (no capillaries) (b) Lungs Capillary Body cells (no capillaries) (a) Tracheae Figure 23.16b 111 The Structure and Function of Surfaces 112 Lungs Body (within lung) are located in only one part of the body and are the most common respiratory of snails, some spiders, and terrestrial vertebrates. The circulatory system transports gases between the respiratory and the rest of the body. Capillary (b) Lungs
Figure 23.17 113 Figure 23.17a 114 Skin (entire body ) RESPIRATORY ORGANS Skin (entire body ) Gills (extensions of the body ) Tracheae (branching internal tubes) Lungs (localized internal organs) Gills Moist skin of a leech Gills of a sea slug Tracheae (internal tubes) Tracheae of a silk moth caterpillar Model of a pair of human lungs Moist skin of a leech Figure 23.17b 115 Figure 23.17c 116 Gills (extensions of the body ) Tracheae (branching internal tubes) Gills Tracheae (internal tubes) Gills of a sea slug Tracheae of a silk moth caterpillar
Figure 23.17d Lungs (localized internal organs) 117 THE HUMAN RESPIRATORY SYSTEM The human respiratory system has three phases of gas exchange: 118 1. breathing, the ventilation of the lungs by alternate inhalation and exhalation, 2. transport of oxygen from the lungs to the rest of the body via the circulatory system, and 3. diffusion of oxygen from the blood and release of into the blood by cells of the body. Model of a pair of human lungs Figure 23.18-1 119 Figure 23.18-2 120 1 Breathing 1 Breathing Lung Lung 2 Transport of gases by the circulatory system Circulatory system Circulatory system
Figure 23.18-3 121 1 Breathing Lung 2 Transport of gases by the circulatory system Circulatory system 3 Exchange of gases with body cells Mitochondria Capillary Cell