Blood is essential for human life — carrying crucial substances like dissolved oxygen and nutrients to the cells. It also flushes out excess or toxic metabolic waste from these same cells.
Blood travels throughout the body via blood vessels which are long tubes that channel blood from the heart and cycle it back. Think of them as the pipes in the human plumbing system. Just like water pipes in a house, we want to avoid blocking the lines with crud or inflammation. Clogged blood vessels lead to many harmful health conditions.
Arteries carry enriched blood away from the heart. They are the thickest blood vessels and use contracting walls to move the blood throughout the body. Arterial walls have three layers: a tough outer covering, a layer of muscle and flexible tissue, and a smooth inner lining to help the blood flow.
The largest artery is the aorta. It attaches to the left ventricle (chamber) of the heart and extends down to the abdomen. There, it forks into two smaller iliac arteries, located at the fourth lumbar vertebra. These two arteries feed networks of smaller blood vessels throughout the body.
The pulmonary artery carries deoxygenated blood that contains carbon dioxide from the right side of the heart to the lungs. It splits into two arteries that connect to the right and left lungs, which remove the carbon dioxide and add oxygen before sending the replenished blood back to the heart to start the pumping process all over again.
Carbon dioxide is used to add the fizz to carbonated beverages. It is also used in fire extinguishers as an inerting agent. (Inerting “is the process in which a substance is converted from a reactive or flammable condition to a non-flammable, non-reactive or a safe state.” An inert gas reduces or replaces the normal oxygen concentration in breathing air.) Carbon dioxide is toxic to cells and, in high concentrations, can be lethal.
Veins return circulated blood pumped by the arterial system to the heart. Although thinner and less flexible than arteries, veins also have three wall layers. Veins have small valves that keep the blood flowing in a forward direction. When these valves stop working properly, blood pools to create dark varicose veins just under the surface of the skin.
Tiny capillaries connect the arteries and veins. They exchange nutrients and oxygen in the cells and remove metabolic wastes like carbon dioxide.
Human blood is made up of blood cells suspended in blood plasma. Plasma constitutes more than half (55 percent) of our blood fluid and is 92 percent water by volume. Plasma contains “proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and blood cells themselves.”
Most blood cells are red (called RBCs or erythrocytes). There are also white blood cells (WBCs or leukocytes) and platelets (also called thrombocytes), which help blood clot. RBCs contain the iron-rich protein hemoglobin which helps blood transport oxygen throughout the circulatory system.
Did you know that your blood is bright red when its hemoglobin is oxygenated (has oxygen) and dark red when it is deoxygenated (has no or less oxygen)?
Blood, tissues, and bones together make up our total body water. Staying hydrated is very important to overall health.
Reduced blood flow is called ischemia and can be both dangerous and hard to detect. Here are nine symptoms that mean your blood circulation is very poor and needs immediate attention:
- Numbness in the Limbs
- Slow Healing Time
- Dry Skin
- Varicose Veins
- Reduced Cognitive Ability
- Loss of Appetite
- Cold Extremities
- Constant Sleepiness
- Weakened Immune System
A strong circulatory system helps maintain a healthy immune system. I’ll share some tips on how to improve blood flow throughout your body in the following article.