17 



Tne Circulatory System 



A. Introduction 



1. Definition 



2. Major subdivisions of the circulatory system 



B. Development of the basic features of the arteriovenous system 



1. The basic plan of the arteriovenous system 



2. Development of the primitive heart and blood vessels associated with the primi- 

 tive gut 



3. Formation of the primitive blood vessels associated with the mesodermal and neural 

 areas 



4. Regions of the primitive vascular system 



C. Histogenesis of the circulatory system 



1. The heart 



2. Formation of the primitive vascular channels and capillaries 



3. Later development of blood vessels 



a. Arteries 



b. Veins 



c. Capillaries 



4. Hematopoiesis (Hemopoiesis) 



a. Theories of blood-cell origin 



b. Places of blood-cell origin 



1 ) Early embryonic origin of blood cells 



2) Later sites of blood-cell formation 



3) Characteristics of development of the erythrocyte 



4) Characteristics of various white blood cells 



a) Granulocytes 



b) Lymphoid forms 



D. Morphogenesis of the circulatory system 



1. Introduction 



2. Transformation of the converging veins of the early embryonic heart into the 

 major veins which enter the adult form of the heart 



a. Alteration of the primitive converging veins of the heart in the shark, Squalus 

 acanthias 



b. Changes in the primitive converging veins of the heart in the anuran amphibia 



1 ) The vitelline veins 



2) Lateral (ventral abdominal) veins 



3) Formation of the inferior vena cava 



4) Formation of the renal portal system 



5) Precaval veins 



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