Main Organs

The heart is a muscular pump that controls blood flow throughout the body. The heart is the key organ in the Circulatory System. It beats around 60 - 100 times per minute. It beats about 100,000 times a day. And more than 30 million times per year. The heart is about the size of when you clench your fist. The heart receives messages telling it to beat more or less blood, for whatever the body needs. If you are excited or happy, the heart beats more, when you are sleeping it beats just enough blood. https://www.rchsd.org/health-articles/heart-and-circulatory-system/

Arteries- Arteries carry blood away from the heart. They also are the thickest blood vessels that have muscular walls. The Arterial wall has three layers, the endothelial, media, and the adventitia layer. Once the arteries get further away from the heart, they branch off into smaller arteries called arterioles. https://www.rchsd.org/health-articles/heart-and-circulatory-system/

Veins- Veins, unlike arteries carry blood to the heart. However, veins share the same layers arteries have the endothelial, media, and the adventitia layer. The two largest veins your body has are the superior and inferior vena cavae. The superior vein is located on top of your heart while in the inferior is obviously below. https://www.rchsd.org/health-articles/heart-and-circulatory-system/

Lungs- Lungs are located behind the heart and have an elastic and spongy feel. They make up a lot of chest cavity. The right lung consists of 3 lobes while the left consists of two. When we breathe, the air travels through the lungs through tubes and passages. The lung aids in the Circulatory System and allows it to function properly. http://lsa.colorado.edu/essence/texts/lungs.html

Portal Vessel- The Portal Vein moves blood from the spleen and gastrointestinal tract to the liver. It supplies about 75% of all blood flow to the liver. In fact, the portal vein is not even a real vein as it does not supply the heart with blood. https://www.healthline.com/human-body-maps/portal-vein#2