Capillaries

Capillaries are the smallest blood vessels in the body, with a diameter just large enough for red blood cells to pass through in single file. They connect the arterioles (small arteries) and venules (small veins) and are the site of exchange of gases, nutrients, and waste products between the blood and the surrounding tissues.

Structure of Capillaries

Capillaries are composed of a single layer of endothelial cells, which are thin-walled and allow for the exchange of substances between the blood and tissues. Their walls are so thin that oxygen, nutrients, and waste products can easily pass through.

Function of Capillaries

The primary function of capillaries is to facilitate the exchange of gases, nutrients, and waste products between the blood and the surrounding tissues. Oxygen and nutrients are delivered to the tissues, while carbon dioxide and waste products are picked up from the tissues for removal from the body.

Study Guide

What are capillaries?
Describe the structure of capillaries.
What is the function of capillaries?
How do capillaries facilitate the exchange of substances?
What is the role of capillaries in the circulatory system?

Now that you have a good understanding of capillaries, it's important to review and reinforce your knowledge through practice questions and diagrams showing the structure and function of capillaries.

◂Science Worksheets and Study Guides Kindergarten. Living and Nonliving

The resources above cover the following skills:

PHYSICAL SCIENCE (NGSS)

Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.

Analyze data to determine if a design solution works as intended to change the speed or direction of an object with a push or a pull.

EARTH AND SPACE SCIENCE (NGSS)

Earth and Human Activity