. All of your answers should be written in your own words, using full sentences, correct terminology, and proper spelling and grammar.

  1. Explain the anatomical concepts associated with the vascular system. Summarize this module’s key points in 5-6 sentences.
  2. Explain the physiological concepts associated with the vascular system. Summarize this module’s key points in 5-6 sentences.
  3. How will you apply the concepts you have learned about the heart in real life and in your future career?
  4. Which topic within this module has been the most valuable to your learning experience and why?
  5. Which topic(s) within this module did you struggle to understand and why?
  6. (Optional) Do you have any suggestions for your instructor on how they could help you connect with the difficult topics you’ve noted?

The blood vessels serve as the irrigation system that connects the heart to all other structures in the body. If all of the vessels in one adult human were laid end to end, they would span more than 100,000 miles; that would be 4x around the equator! The three main types of blood vessels are arteries, veins, and capillaries.

Veins and Arteries

Veins carry blood toward the heart, and arteries carry blood away from the heart. As arteries leave the heart, they split and become smaller; these smaller arteries are called arterioles. These arterioles then connect with even thinner vessels called capillaries. From here, the blood goes to tiny veins called venues, with continuation into bigger veins that bring the blood back to the heart. The acronym VEAL: veins enter (the heart), arteries leave (the heart) can help you remember the blood’s direction through the major vessels.

Layers of Arteries and Veins

The arteries and veins are comprised of three layers. From superficial to deep, these are the tunica externa, media, and intima. The tunica externa is primarily protective collagen. The tunica media contains smooth muscle that can contract and relax. Contraction is called vasoconstriction, and relaxation is called vasodilation. The inner, the tunica intima or endothelium, layer is made of a single layer of epithelial cells. When this inner layer is damaged, the clotting process is initiated.

Arteries carry blood away from the heart and come in three major varieties: elastic arteries, muscular arteries, arterioles. The elastic arteries are also called conducting arteries. The muscular arteries are also called distributing arteries. The arterioles are the tiny end branches of arteries, which connect to capillaries.

Artery structure and types (Betts et al., 2013)


Veins carry blood toward the heart. They begin as tiny venules branching off the capillaries, then merge together into medium and then large veins that enter the heart. Veins have valves to help prevent backflow. When valves, often in the lower extremity, become dysfunctional varicose veins may emerge.


Vein structure and types (Betts et al., 2013)


The capillaries connect arterioles and venules. The capillaries have only two layers: the tunica media and tunica intima. Their thin layers allow them to perform their primary function of diffusing gasses, nutrients, and wastes through their walls.


Circulatory system overview (Betts et al., 2013)

Now that we have examined the anatomical foundations, we will learn more about how they function together with the heart.

The cardiac cycle is a term used to describe how all of the events, mechanical and electrical, coordinate the blood flow through the heart in a sin