How does the structure of capillaries compare to that of arteries and veins?
How does the structure of capillaries compare to that of arteries and veins?
How does the structure of capillaries compare to that of arteries and veins?
Capillaries consist of a single layer of epithelial cells, the endothelium tunic (tunica intima). Veins and arteries both have two further tunics that surround the endothelium: the middle, tunica media is composed of smooth muscle, while the outer tunica externa is connective tissue (collagen and elastic fibers).
Is the cross sectional area of capillaries larger than arteries?
At the beginning of the arterial system, the total cross-sectional area is the cross-sectional area of the aorta. Although each capillary is small, the total area occupied by the capillaries is approximately 600 times greater than that of the aorta due to their large number (over 1 billion).
What is the total cross sectional area of capillaries?
Total cross sectional area of capillaries
| Value | 6000 cm^2 Range: Table – link cm^2 |
|---|---|
| Organism | Human Homo sapiens |
| Reference | Lauralee Sherwood, Human Physiology: From Cells to Systems, Wadsworth publishing company 3rd edition 1997, p.311 table 10-1 & p.323 figure 10-16 – link |
What are the major arteries and veins in the body and which regions do they serve?
The major blood vessels that are connected to the heart include the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs, where it is oxygenated), the pulmonary veins (which bring oxygen-rich blood from the lungs to the heart) and the …
Which blood vessels have the largest cross-sectional area?
Capillaries have the largest total cross-sectional and surface area. Veins are thin-walled blood vessels that return deoxygenated blood to the heart.
Which blood vessel has the smallest cross-sectional area?
aorta
The cross sectional area, of any part of the vasculature is taken as the sum of all the vessels at that level and not of a single vessel individually. Hence, the aorta which is a single vessel, has the smallest cross sectional area of 2.5cm^2.
Why do arteries have a different structure to veins?
Blood is transported in arteries , veins and capillaries ….Structure and function of blood vessels.
| Arteries | Veins |
|---|---|
| Have thick muscular and elastic walls to pump and accommodate blood | Have thin walls – have less muscular tissue than arteries |
| A type of supporting tissue called connective tissue provides strength | Have less connective tissue than arteries |
What is the difference in the structure of arteries and veins?
Arteries have thick, elastic, muscular walls whereas veins have thin walls with few elastic fibres. Arteries need these properties to give them the strength and elasticity needed to cope with the high pressure surges of oxygenated blood coming from the heart.
Which blood vessel has the smallest cross sectional area?
What is the relationship between blood flow and total cross-sectional area?
The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood vessels. As the total cross-sectional area of the vessels increases, the velocity of flow decreases. Blood flow is slowest in the capillaries, which allows time for exchange of gases and nutrients.