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

2. Objective 1 Blood 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, thin Small vein: thin tunica media tunica externa thick tunica externa
maintains its shape collapsible

4. Objective 2 Some Human Arteries:

8. Objective 3 Major Veins of the Body

12. Objective 4 Pulmonary 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

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

14. Objective 6 Cerebral Circulation
Arteries

15. Vessels of the Circle of Willis

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

17. Venous Drainage

18. Objective 7 and 8 Hepatic 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:
Remove, store and bioconvert sugars, fatty acids and amino acids
Detoxification of the blood
Remove bacteria and other debris

19. Hepatic Portal System in the Cat:
Superior Mesenteric Vein C. Hepatic Portal Vein
Inferior Mesenteric Vein D. Gastrosplenic Vein

20. 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

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