Ashtanga Yoga and the Circulatory System (part 2)

If we focus on only one aspect of the entire yoga practice, we fail. Just as the breath cannot be separated from the man, the mind cannot be separated either. The body, the breath, and the mind are linked.

All aspects of this practice are linked. As are all aspects of our human existence linked. We are here to serve. Serve each other.

If we practice only for ourselves, only for an asana or for a ‘good stretch’ we will certainly fail to reach enlightenment. We will serve to separate ourselves from our fellow beings. Separate ourselves from compassion, understanding, and empathy, making ourselves into a flexible asshole. 

Flexible or not, all humans depend on breathing to live. Specifically, humans need oxygen for life. The air that we breathe is about 21% oxygen, even at the top of a mountain when it feels difficult to breathe, it’s still about 21% up there. All organs require oxygen for metabolism, but the heart and brain are particularly sensitive to a lack of oxygen.

A shortage of oxygen to these organs for a few minutes is fatal.

Oxygen is transported around the body in the blood attached like a magnet to an iron-containing protein called hemoglobin. (Hgb) We breathe oxygen in through the nose where those hairs and mucus filter out dirt and dust particles. The air swirls around in the back of the nose giving it time to warm up and humidify before traveling down the trachea. The trachea is about an inch in diameter with cartilage rings around it to prevent it from collapsing or over inflating. Like when you suck on a straw with a piece of boba or coconut flesh inside, these rings keep the shape of the trachea.

The trachea divides into branches called the bronchi that further subdivide into the bronchiole. When the diaphragm contracts air is pulled into the lungs and travels through these tubes that look like the roots of a tree. At the end of the bronchiole are pods called alveoli that are continually fed blood from the heart. Alveoli is where gas exchange takes place in the lungs. The warm humidified air that we took in, swirls around inside these pods waiting to be carried through the body. 

If these pods are filled with smoke, or fluid then we have less available area to release the waste and trade up for the oxygen that the body needs to function. Oxygen (O2) is more attractive and fits together better with the magnetic force of the hemoglobin in the blood than carbon dioxide (CO2). When blood is squeezed through the tiny vessels around the alveoli CO2 pops off and is replaced with O2.

The blood now rich in O2 travels back to the heart via the pulmonary vein to the top left chamber of the heart.

The heart is the emperor controlling all the other organs, it is at our center and the root of our life. It is protected and held in place by the pericardium. Divided into 4 chambers, left and right, top and bottom, the heart is responsible for the flow of blood throughout the body, and is often thought of as the main energy center of the body, the 4th chakra, our place of feeling.


An energy center is an area within your being through which your energy focuses, distributes, and flows. This energy flow has been referred to as Shakti, Spirit, and Chi, and it plays an intricate part in your life. You feel the heart’s energy all the time.” The Untethered Soul - Michael Singer

The heartbeat/energy flow, can be felt physically, through palpating a person’s pulse, and monitored electrically, through an EKG. Each contraction and relaxation is called a heartbeat.

When the heart relaxes, blood moves through one way valves from the top areas of the heart (atrium) to the lower half called the ventricles. When it receives a signal from the vagus nerve an electrical impulse contracts the muscles around the ventricles moving blood away from the heart.

Blood pressure is a measurement of how strong the contraction is. The top number is the amount of force the heart is exerting to push blood around the body. The bottom number is the amount of pressure it takes to fill the heart back up with blood to do it all over again.

The oxygen rich blood leaves the left ventricle to the aorta. The aorta is the largest artery in the body. Arteries are blood vessels with a muscular lining around the tube that produce a contraction, called a pulse that can be felt under certain parts of the body. The pulse is synchronized with the heart beat to move blood rich in O2 further along the body and away from the heart.

Arteries divide, and branch out becoming smaller and smaller in diameter until the smooth muscle disappear. When the smooth muscle disappears the diameter of the tube is only wide enough for a single cell to fit through at a time. These tiny tubes are called capillaries where oxygen is exchanged for carbon dioxide, and sugars and other nutrients are picked up into, and exchanged in the bloodstream. As the blood cell moves through the tiny capillary it must distort it’s shape which changes the magnetic bond between the hemoglobin and oxygen and allows for the larger CO2 molecule to take it’s place for the return journey back to the heart.

The capillaries eventually join back together, after covering the surface of a particular tissue, to form veins. Unlike arteries, veins have no muscles to move blood around the body and are reliant upon the structural muscles to facilitate the movement of blood. This is one of the reasons veins are sometimes visible protruding under the surface of skin. Veins link up growing larger in diameter until emptying into two main branches called the inferior and superior venae cava. These branches almost continuously empty deoxygenated blood into the right atrium.

When the heart relaxes the one way valve opens up allowing this blood to enter into the right ventricle. As before when the heart receives an electrical signal to contract, the ventricles contract. The blood carrying CO2 moves away from the heart and to the lungs through the pulmonary artery. This artery, like the others divide and spread out into capillaries around the alveoli of the lungs, the air pods. The blood cell is squeezed again changing the shape of the hemoglobin and bumping out the CO2 for O2.

When the diaphragm relaxes it compresses the lungs pushing the carbon dioxide up and out of the body.

Morgan Lee