Learning Materials
Features
Discover
Blood vessels are tube-like structures that facilitate blood movement to specific tissues in the body. One can compare blood vessels to transport networks in a city.
Millions of flashcards designed to help you ace your studies
Sign up for freeWhat is Vaia?
How does Vaia help me study more efficiently?
Where can I find more explanations like this?
What's smart about Vaia's flashcards?
Can I create my own content on Vaia?
How does spaced repetition work in Vaia flashcards?
What can you do with flashcards in Vaia?
Is Vaia a science-based learning platform?
How do Vaia's smart learning plans support your exam prep?
Can you create your own study sets in Vaia?
What is Vaia?
How does Vaia help me study more efficiently?
Where can I find more explanations like this?
What's smart about Vaia's flashcards?
Can I create my own content on Vaia?
How does spaced repetition work in Vaia flashcards?
What can you do with flashcards in Vaia?
Is Vaia a science-based learning platform?
How do Vaia's smart learning plans support your exam prep?
Can you create your own study sets in Vaia?
Achieve better grades quicker with Premium
Geld-zurück-Garantie, wenn du durch die Prüfung fällst
Did you know that StudySmarter supports you beyond learning?
Review generated flashcards
Start learning or create your own AI flashcards
Team Blood vessels Teachers
There are five types of blood vessels: arteries, arterioles, capillaries, venules, and veins. We will look in more detail at the characteristics of each type later on in the explanation.
You also need to know the names of blood vessels that supply blood to the heart, lungs, and kidneys, as summarised in the table:
The structures of arteries, veins, and capillaries differ from each other. Arterioles branch off from arteries and venules branch off from veins, similar to how bronchioles branch off from bronchi (you can find out more about this in the Human Gas Exchange explanation).
Thus, arterioles and venules have similar structures to their ‘parent vessels’ – arteries and veins. However, arterioles have a thicker muscle wall and a thinner elastic layer.
To look at the structure of these blood vessels in a bit more detail, we can do a cross-section of arteries, capillaries and veins to see the layers making up these blood vessels, as shown in the table below:
| Artery | Capillary | Vein |
Thick wall Wall has four layers:
Narrower lumen than vein | Wall is a one-cell thick layer. Narrow diameter, thus narrow lumen | Thinner wall than artery Wall has four layers:
Wide lumen |
Lumen is the hollow cavity of an organ or blood vessel.
Study tip: tunica is the Latin name given to the layers of the blood vessel. Furthermore, students may be confused between epithelium and endothelium. Epithelium covers other organs (e.g., airways, small intestine) whereas endothelium is specific to blood vessels.
In an exam, you may be asked to draw out the structures of blood vessels based on microscope slides. The diagram below demonstrates how to draw these blood vessels out. Do note the relative proportions of each layer comprising the vessel wall.
Fig. 1 - Drawing of an artery, vein, and capillary
Given how the structure of these blood vessels differs from each other, you may have guessed that each type of blood vessel functions differently. Below is a summary of the role of these blood vessels:
Arteries and arterioles carry oxygenated blood, whereas veins and venules carry deoxygenated blood.
However, there are exceptions to this rule: pulmonary vessels and umbilical vessels (which supply blood from the mother to the fetus during pregnancy) do not carry oxygenated blood. Pulmonary and umbilical arteries carry deoxygenated blood whereas pulmonary and umbilical veins carry oxygenated blood.
Study tip: some students may confuse bronchi and bronchioles as blood vessels. These are not blood vessels. Instead, they belong to the respiratory system and transport air into and out of the lungs.
We will explore in detail how the structure of blood vessels affects their function.
First off, we will look at how the structure of arteries affects their function. Arteries have:
Considering arterioles have thicker muscle layers and thinner elastic layers than arteries, how does the structure of arterioles affect their function? The thicker muscle layers of arterioles allows arterioles to either increase or decrease blood into capillaries. This plays an important role in temperature control. Arterioles have thinner elastic layers because blood travels in arterioles at lower pressures, reducing the need for an elastin layer. This lower pressure is due to the fact that arterioles are further away from the heart when compared to arteries, which have more elastin.
Now, let's take a look at the relationship between the structure of capillaries and their function. Capillaries are sites of substance exchange, for instance, gas exchange occurs in the alveoli capillaries. As such, they have:
As for veins, they have:
Furthermore, veins have adapted to prevent a backflow of blood by being located in muscular regions of the body (e.g., the legs and chest). The contraction of these muscles helps push blood to the heart.
Study tip: make sure you use the keywords that refer specifically to blood flow when writing your answers. For example, the muscle walls constrict and dilate, whereas the elastic walls stretch and recoil.
Is all the detail behind all the blood vessels overwhelming? The table below compares the blood vessels to help you grasp the addressed concepts:
| Artery | Capillary | Vein | |
| Wall | Thick | Thin (one cell thick) | Thin |
| Muscle layer | Thick | Absent | Thin |
| Elastic layer | Thick | Absent | Thin |
| Size of lumen | Small | Very small (10μm) | Large |
| Valves | Absent | Absent | Present |
Sign up for free to gain access to all our flashcards.
What are blood vessels?
Blood vessels are pipe-like structures that transport blood from the heart to tissues in the body and vice versa.
Which type of blood vessel contains valves?
Veins and venules contain valves, essentially blood vessels whose blood flow is under low pressure.
Which blood vessels carry oxygenated blood?
Arteries and arterioles carry oxygenated blood, except for the pulmonary artery.
What are the five major blood vessels?
The five major blood vessels include arteries, arterioles, capillaries, venules, and veins.
What blood vessels carry blood away from the heart?
Arteries carry blood away from the heart, including the pulmonary artery.
What are venules and arterioles?
Venules and arterioles are blood vessels that branch off veins and arteries. They are similar in structure and function as veins and arteries, though they are smaller in diameter.
What are the 3 layers of a blood vessel?
Arteries and veins (including arterioles and venules) have three layers to them. These layers include the external layer, internal layer, and endothelial layer.
At StudySmarter, we have created a learning platform that serves millions of students. Meet the people who work hard to deliver fact based content as well as making sure it is verified.
Lily Hulatt is a Digital Content Specialist with over three years of experience in content strategy and curriculum design. She gained her PhD in English Literature from Durham University in 2022, taught in Durham University’s English Studies Department, and has contributed to a number of publications. Lily specialises in English Literature, English Language, History, and Philosophy.
Get to know Lily
Gabriel Freitas is an AI Engineer with a solid experience in software development, machine learning algorithms, and generative AI, including large language models’ (LLMs) applications. Graduated in Electrical Engineering at the University of São Paulo, he is currently pursuing an MSc in Computer Engineering at the University of Campinas, specializing in machine learning topics. Gabriel has a strong background in software engineering and has worked on projects involving computer vision, embedded AI, and LLM applications.
Get to know Gabriel
Vaia is a globally recognized educational technology company, offering a holistic learning platform designed for students of all ages and educational levels. Our platform provides learning support for a wide range of subjects, including STEM, Social Sciences, and Languages and also helps students to successfully master various tests and exams worldwide, such as GCSE, A Level, SAT, ACT, Abitur, and more. We offer an extensive library of learning materials, including interactive flashcards, comprehensive textbook solutions, and detailed explanations. The cutting-edge technology and tools we provide help students create their own learning materials. StudySmarter’s content is not only expert-verified but also regularly updated to ensure accuracy and relevance.
Learn moreSave explanations to your personalised space and access them anytime, anywhere!
Sign up with Email Sign up with AppleBy signing up, you agree to the Terms and Conditions and the Privacy Policy of Vaia.
Already have an account? Log in
Sign up to highlight and take notes. It’s 100% free.
Explanations 
Textbooks 
Exams 
GCSE 
IGCSE 
AS 
A Level 
International A Level 
University Admissions Tests 
Flashcards 
Vaia AI 
Notes 
Study Plans 
Study Sets 
Find a job 
Find a degree 
Student Deals 
Magazine 
Mobile App 
