Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 5: Problem 3

Which of the three types of blood vessels are most numerous? Explain. (page 93 )

Short Answer

Expert verified
Capillaries are the most numerous blood vessels in the human body, with an estimated 40-50 billion compared to the much smaller number of arteries and veins. This is because capillaries play a vital role in the exchange of nutrients, oxygen, and waste products between blood and body tissues. Their extensive network also helps regulate body temperature by distributing blood close to the skin's surface.

Step by step solution

01

Introduction to Blood Vessels

There are mainly three types of blood vessels in the human body: arteries, veins, and capillaries. Blood vessels play a critical role in the circulatory system, transporting blood to and from all parts of the body.
02

Type 1: Arteries

Arteries are blood vessels that carry blood away from the heart. They have thick walls composed of three layers: an inner layer of endothelial cells, a middle layer called tunica media mainly made up of smooth muscle and elastic fibers, and an outermost layer called tunica externa. Arteries are responsible for transporting oxygenated blood and nutrients to all parts of the body.
03

Type 2: Veins

Veins are blood vessels that carry deoxygenated blood back to the heart. Their walls are also made up of three layers like arteries, but with thinner tunica media. Veins contain valves that prevent blood from flowing backward, ensuring its return to the heart.
04

Type 3: Capillaries

Capillaries are the smallest and thinnest blood vessels in the body. They are composed of a single layer of endothelial cells and are responsible for connecting the arterioles (small arteries) to venules (small veins). Capillaries play a vital role in the exchange of nutrients, oxygen, and waste products between the blood and body tissues.
05

Determining the Most Numerous Blood Vessel

Out of the three types of blood vessels, capillaries are the most numerous. The estimated number of capillaries in the human body ranges between 40-50 billion, while the number of arteries and veins is much smaller.
06

Explanation of Capillary Abundance

Capillaries are the most numerous blood vessels because they are the primary sites for the exchange of materials between blood and tissues. The large number of capillaries allows for efficient nutrient and oxygen delivery to cells and effective removal of waste products. This extensive network of capillaries also helps to regulate body temperature, as they are responsible for distributing blood close to the skin's surface, where heat can be lost or conserved.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

When the atria contract, the blood flows a. into the attached blood vessels. b. into the ventricles. c. through the atrioventricular valves. d. to the lungs. e. Both b and c are correct.

If a person's blood pressure is \(115 \mathrm{mm}\) Hg over \(75 \mathrm{mm} \mathrm{Hg}\), the 75 represents a. systolic pressure. b. diastolic pressure. c. pressure during ventricular relaxation. d. Both b and c are correct.

During ventricular diastole, a. blood flows into the aorta. b. the ventricles contract. c. the semilunar valves are closed. d. Both a and b are correct.

Match the descriptions to the blood vessel in the key. Answers may be used more than once. Key: a. venules b. veins c. capillaries d. arteries e. arterioles Take blood away from the heart

Which of these associations is mismatched? a. left ventricle- aorta b. right ventricle- -pulmonary trunk c. right atrium- vena cava d. left atrium-pulmonary artery e. Both b and c are incorrectly matched.
See all solutions

Recommended explanations on Biology Textbooks

Plant Biology

Read Explanation

Bioenergetics

Read Explanation

Cells

Read Explanation

Biological Molecules

Read Explanation

Ecology

Read Explanation

Cell Cycle

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free