4. Structure of Blood Vessels

5. Portal Systems Hepatic portal system Renal portal system Renal portal system Hepatic portal system Hypophyseal portal system Blood from capillaries of the tail digestive tract, pancreas and spleen Hypothalamus (contains pituitary regulating hormones) To capillaries of kidney liver Adenohypophysis Continue to Heart Heart Heart

6. Pathway of Blood Arteries Arterioles (Precapillary sphincter) Capillaries (capillary shunts) Venules Veins

8. Angiognesis

9. Blood Serum-plasma without fibrinogen (clotting substance)

12. Formed Elements

13. Formed Elements Lifespan: 3-4 months Number: 25 trillion Reduces hemoglobin- when oxygen is freed

14. Formed Elements

15. Formed Elements Platelets -participate with fibrinogen in the clotting of blood -tiny fragments of stem cells (megakaryotes) found in the bone marrow

16. Heart and Its Evolution

19. Single Circuit Blood passes from heart to the gills From gills directly to all parts of the body Systemic circuit – oxygenated blood to organs and returns oxygen depleted blood to the heart Pulmonary circuit – deoxygenated blood from heart to lungs Returns to the heart Double Circuit Fishes Craniates who abandoned gills

23. 1. Ventricular contraction – creates suction 2. Filling of sinus venosus 3. Atrium relaxes – blood from sinus venosus  valves  sinoatrial aperture  atrium Atrial contraction  atrioventricular septum  valves  relaxing ventricle Conal constriction

30. Heart valves

34. Innervation of the Heart

35. ARTERIAL CHANNELS AND THEIR MODIFICATIONS Circulatory System ARTERIAL CHANNELS supply most organs with oxygenated blood, although they carry deoxygenated blood to respiratory organs

41. SUMMARY OF AORTIC ARCH OF FISHES AORTIC ARCH SQUALUS TELEOST PROTOPTERUS DIPNOANS, AMIA, POLYPTERUS 1 st pair (before the 6 th pair appears) ventral segments – disappears dorsal segments – efferent spiracular arteries disappear 2 nd pair first pretrematic arteries disappear 3 rd pair posttrematic arteries posttrematic arteries not become interrupted by gill capillaries 4 th pair posttrematic arteries posttrematic arteries - not become interrupted by gill capillaries - bear external gills 5 th pair posttrematic arteries posttrematic arteries 6 th pair posttrematic arteries posttrematic arteries Pulmonary Vein

55. AORTIC ARCH OF BIRDS & MAMMALS FIGURE 14.25 Page 334 FIGURE 14.26 Page 334 Part Birds Mammals 1 st Aortic Arch x x 2 nd Aortic Arch x x 3 rd Aortic Arch internal carotid internal carotid 4 th Aortic Arch x - arch of aorta directed to the right (fig. 14.25) Base remains - arch of aorta directed to the left (14.26) 5 th Aortic Arch x x 6 th Aortic Arch Right - x Left - Pulmonary artery Right – x Left - Pulmonary Artery Ductus Caroticus x x Ductus Arteriosus closes before hatching closes with the first gasp of air into the lungs Paired embryonic ventral aorta left and right common carotid and external carotid arteries left and right common carotid and external carotid arteries

66. VENOUS CHANNELS AND THEIR MODIFICATIONS

81. CIRCULATION IN THE MAMMALIAN FETUS, AND CHANGES AT BIRTH

82. Caudal end of dorsal aorta Umbilical arteries Umbilical cord Placenta Umbilical Vein Ductus Venosus Liver Postcava Right atrium Interarterial foramen Left atrium Left ventricle Systemic arch Major venous channels Right ventricle Pulmonary Trunk Lungs

86. Fetal Adult foramen ovale fossa ovalis ductus arteriosus ligamentum arteriosum extra-hepatic portion of the fetal left umbilical vein ligamentum teres hepatis (the "round ligament of the liver") intra-hepatic portion of the fetal left umbilical vein (the ductus venosus) ligamentum venosum proximal portions of the fetal left and right umbilical arteries umbilical branches of the internal iliac arteries distal portions of the fetal left and right umbilical arteries medial umbilical ligaments (urachus)

87. MAJOR CIRCULATORY CHANGES WHICH ADAPT THE ORGANISM FOR PULMONARY RESPIRATION The interarterial valve is pressed against the interarterial foramen by the sudden increase in pressure in the left atrium that results from the greatly increased volume of blood entering from the lungs. The umbilical arteries and vein are severed at the umbilicus. Eventually, the umbilical arteries from bladder to navel are converted into lateral umbilical ligaments. No blood flows through the umbilical vein since source has been cut off. This becomes the round ligament of the liver and the it becomes the ligamentum venosum. The ductus arteriosus closes as a result of nerve impulses passing to its muscular wall.

89. Failure of the foramen ovale to close or of the ductus arteriosus to constrict results in…. CYANOSIS - Blueness of the skin, lips and nail bed in humans

90. SYSTEMATIC SUMMARY OF RESPIRATION AND CIRCULATION

92. Gill – breathing fishes can resort to pulse pumping when challenged by low-oxygen partial pressures. A species may shift strategies during its life history ( a gill-breathing larva shifting to pulse pumping at metamorphosis). Any shift to aspiration mode would potentially conserve energy. Aspiration breathing is seen in all amniotes. Fossil rhipidistian fishes with lungs were incapable of pulse pumping due to their heavy overlapping ribs and scales. The large body size and ribs of early tetrapods preclude pulse pumping.

93. LYMPHATIC SYSTEM

94. The LYMPHATIC SYSTEM consists of… 1. thin-walled LYMPH CHANNELS 2. LYMPH (fluid) 3. LYMPH HEARTS 4. LYMPH NODES (birds and mammals) 5. solitary or aggregated masses of LYMPH NODULES ex. SPLEEN

95. The system begins in LYMPH CAPILLARIES or in LYMPH SINUSOIDS . Fluid empties to a vein. Valves at these exits prevent the influx of venous blood into the lymph channels.

96. Capillaries and sinusoids penetrate most of the soft tissues of the body other than the liver and the nervous system. They also collect interstitial fluids. A lymphatic network consisting of long, narrow, discrete tubular vessels with a modicum of smooth muscle in the walls is found only in birds and mammals.

97. LACTEALS - lymphatics in intestinal villi - CHYLE – lymph found in these vessels; milky appearance HEMOLYMPH - lymphatics which contain red blood cells - Living agnathans, cartilaginous fishes and humans

98. Lymph channels that drain the body wall, limbs, and tail of craniates empty into nearby veins at the base of the tail, trunk and neck. Lymph channels draining viscera are often paired in most craniates but in mammals, a single thoracic duct commences in a large abdominal lymph sinus, the cisterna chyli and empties into a branchicephalic of left subclavian vein, or into external or internal jugular veins.

100. FACTORS THAT CONTROL THE FLOW OF LYMPH Lymph hearts at advantageous locations along lymph pathways in fishes, amphibians and reptiles (except postembryonic birds). Frogs: 2 pairs of lymph hearts Urodeles: 16 pairs Caecilians: 100 pairs Amphibians have more tissue fluids to manipulate than other craniates so their lymph hearts move a proportionately larger volume of fluid than the hearts of other craniates. Semilunar valves at the exit of the hearts prevent backflow. Lymph hearts are not present in birds after hatching but embryonic birds have them. None has been described in humans.

101. CRANIATE LYMPH FLOW is maintained… … .by activity of the skeletal muscles as they contract and relax … .by movements of the viscera … .by rhythmical changes in intrathoracic pressure that results from breathing

102. LYMPH NODES are masses of hemopoietic tissue interposed along the course of lymph channels of birds and mammals.

103. They are the “swollen glands” you feel in the neck, axilla and groin in humans when there is inflammation in areas drained. The endothelium of the sinusoidal passageways include phagocytes that ingest bacteria and other particles. The nodes are the 2 nd line of defense against bacterial infections acquired through the skin, the first line being granulocytes that assemble at the invaded area.

104. LYMPHOID MASSES Spleen Thymus (absent in hagfishes) Tonsils (in humans) Peyer’s Patches (in amniotes) Bursa of fabricius (in young birds)