Blood vessels- discussion, viva

Circulatory system/ Vascular system/ Blood vessels:

1. Name two parts of circulatory system
• Blood vascular system and lymph vascular system
2. Name the 3 layers of blood vessels
• From inside out- tunica intima, tunica media, tunica adventitia
3. What are the components of tunica intima?
• endothelium- simple squamous epithelium 
• subendothelial connective tissue
• internal elastic lamina
4. What are the components of tunica media?
• smooth muscle fibers
• elastic fibers
• reticular fibers
5. What are the components of tunica adventitia?
• connective tissue (collagen, elastic fibers)
• blood vessels/ vasa vasorum
• nerves
• lymphatics
6. Name the smallest blood vessels
• Capillaries, venules
7. Name the different types of capillaries
• Continuous capillaries- endothelial cells join and form uninterrrupted solid endothelial lining. Seen in muscle, skin, connective tissue, nervous tissue, respiratory organs
• Fenestrated capillaries- pores/ fenestrations present in the cytoplasm of endothelial cells for rapid exchange of molecules. Seen in endocrine tissues and glands, small intestine, kidney
• Sinusoidal capillaries- wide gaps present inbetween endothelial cells. Seen in liver, spleen and bone marrow
8. Name the three types of arteries in the body
• Elastic/ large arteries
• Muscular/ medium sized/ distributing arteries
• Arterioles
9. What are the general differences between arteries and veins?
• lumen is intact in artery and collapsed in vein
• the wall of the artery is thicker than the wall of the vein
• tunica media is thick in the artery, tunica adventitia is thick in the vein
• well developed internal and external elastic laminae present in the artery, absent in the vein

Medium sized artery:

1. What is the composition of tunica intima?
• Endothelium- simple squamous epithelium
• Subendothelium- loose connective tissue
• Internal elastic lamina- prominent
2. What is the composition of tunica media?
• Equally thick as tunica adventitia with various amounts of reticular  and elastic fibers, abundant  smooth muscle fibers 
3. What is the composition of tunica adventitia?
• Thickness equal compared to tunica media composed of collagen and elastic connective tissue fibers, blood vessels, nerves and lymphatics
4. What is vasa vasorum?
• These are the small blood vessels supplying the walls of large blood vessels to provide nutrition to tunica media and adventitia
5. Give examples for medium sized artery
• Brachial artery, radial artery, ulnar artery, femoral artery, popliteal artery, etc

Large artery/ Elastic artery:

1. Give examples for large artery
• Aorta, brachiocephalic artery, common carotid artery, subclavian artery, vertebral artery, common iliac artery, pulmonary trunk
2. Why elastic artery has more of elastic fibers?
• The elastic fibers provide great resilience and flexibility during blood flow
3. Name the layers of the blood vessel
• From inside out- tunica intima, tunica media, tunica adventitia
4. What is the composition of tunica intima?
• Endothelium- simple squamous epithelium
• Subendothelium- loose connective tissue
5. What is the composition of tunica media?
• Very thick with various amounts of reticular  and smooth muscle fibers, abundant elastic fibers present in the form of laminae
6. What is the composition of tunica adventitia?
• Thin compared to tunica media composed of collagen and elastic connective tissue fibers, blood vessels, nerves and lymphatics
7. What is vasa vasorum?
• These are the small blood vessels supplying the walls of large blood vessels to provide nutrition to tunica media and adventitia

Large vein:

1. What is the composition of tunica intima?
• Endothelium- simple squamous epithelium
• Subendothelium- loose connective tissue
2. What is the composition of tunica media?
• Thin layer with various amounts of reticular  and elastic fibers, smooth muscle fibers 
3. What is the composition of tunica adventitia?
• Very thick compared to tunica media composed of collagen and elastic connective tissue fibers, blood vessels, nerves, lymphatics and longitudinally arranged smooth muscle fibers. 
4. What is vasa vasorum?
• These are the small blood vessels supplying the walls of large blood vessels to provide nutrition to tunica media and adventitia
5. Give examples for large sized vein
• Portal vein, inferior venacava, superior venacava
6. Give the differences between arteries and veins

• Types	Medium sized artery	Large artery	Large vein
  Tunica intima: Endothelium Subendothelial CT Internal elastic membrane (fenestrated membrane of Henle)	Endothelial cells with basal lamina. Sparse. Well defined wavy structure.	Thick lining endothelium with basal lamina. Well defined with collagen and elastic fibers and smooth muscle cells. Fibroblasts absent. Present, Not distinct.	Endothelial layer with basal lamina. Thin, but also with smooth muscle cells. Not distinct.
  Tunica media External elastic lamina	Mainly of smooth muscle cells with intervening collagen, reticular and elastic fibers. Few or no fibroblasts Prominent	Thickest of the 3 layers. Abundant elastic fibers with intervening smooth muscle cells, collagen fibers and ground substance. Elastic fibers in the form of membranes. Not distinct	Thin consisting of smooth muscle cells, collagen fibers and fibroblasts. Not distinct
  Tunica adventitia	As thick as tunica media. Mainly collagen fibers. Adjacent to tunica media form prominent external elastic lamina.	Less than half the thickness of tunica media. Mainly of collagen fibers with loose network of elastic fibers. Fibroblasts and macrophages present. Vasa vasorum seen.	Thickest of the 3 layers  consisting of longitudinally running smooth muscle cells.  Fibroblasts, collagen and elastic fibers seen. Vasa vasorum extends up to the tunica media.
  Lumen	Round and intact.	Round and intact.	Collapsed and irregular. Larger lumen than the artery.
  E.g.	Radial, ulnar, tibial.	Aorta, pulmonary trunk.	Superior vena cava, inferior vena cava, portal vein.

Please refer the above table for the questions given below:

What are muscular arteries and elastic arteries? What is the functional significance of each layer in the wall of the vessel

What are the differences in the structure between the aorta (large artery) and any medium sized artery

What are the features in the structure of the inferior venacava (large vein)

Give the differences in the structure between large artery and vein

Give the differences between the medium sized artery and vein

Give examples for muscular artery and elastic artery