1. BIOL 204 – Week 3 Lab Blood Vessel Histology Human Arteries and Veins Special Circulatory Pathway

2. Objective 1Blood Vessel Histology Arteries and Veins have three tunics, or tissue layers: Tunica intima (interna) Inner layer of endothelium and subendothelial areolar CT Tunica media smooth muscle and elastic tissue Tunica adventitia (externa) Dense irregular connective tissue

3. Comparison of arteries and veins: Small artery: thick tunica media, thinSmall vein: thin tunica media tunica externa thick tunica externa maintains its shape collapsible

4. Objective 2Some Human Arteries:

9. Objective 3 Major Veins of the Body

13. Objective 4Pulmonary Circulation Functions to bring deoxygenated blood to the lungs for gas exchange and to bring oxygenated blood back to the heart for distribution to body systems Unlike systemic circulation, pulmonary circulation: 1.is a low pressure pathway 2.arteries carry deoxygenated blood; veins carry oxygenated blood

14. Objective 5Trace The Flow of Blood In Pulmonary Circulation

15. Objective 6Cerebral Circulation Arteries

16. Vessels of the Circle of Willis

17. Sheep’s Brain: Structures of the Circle of Willis

18. Venous Drainage

19. Objective 7 and 8Hepatic Portal Circulation Hepatic portal circulation consists of veins that drain blood from digestive viscera, the spleen and pancreas and deliver that blood to the liver for processing: 1.Remove, store and bioconvert sugars, fatty acids and amino acids 2.Detoxification of the blood 3.Remove bacteria and other debris

20. Hepatic Portal System in the Cat: A.Superior Mesenteric VeinC. Hepatic Portal Vein B.Inferior Mesenteric VeinD. Gastrosplenic Vein

21. Objective 9 and 10 Fetal Circulation The structures of fetal circulation allow the placenta to function as an organ for nutrient, waste and gas exchange Note that the: Umbilical arteries carry deoxygenated blood and that the umbilical veins carry oxygenated blood The ductus venosus allows most blood to bypass the nonfunctional fetal liver The foraman ovale and the ductus arteriosus allows most blood to bypass the nonfunctional fetal lungs

22. Umbilical Arteries and Umbilical Vein of a Fetal Umbilical Cord