8 Sep 2019 HYN Himalayan Yoga Academy
The Continuous movement of blood within an organism is called blood circulation. There are three parts of CVS: Heart, Blood Vessels, and Blood. Most importantly circulation and respiration go hand in hand. Good respiration yields a more efficient circulatory system.Further about CARDIOVASCULAR SYSTEM
Physiology of Heart: Cardio-fitness respiration = getting air into the lungs transferring oxygen from lungs to the heart via the pulmonary veins before heart pumps oxygenated blood via the aorta to the tissues of the body. The heart pumps blood through 2 circuits: pulmonary and systemic. But the flow of the blood is unidirectional.
In the pulmonary circulation circuit blood flows from right ventricle to the lungs back to the left atrium this allows the blood to pick up O2 (oxygen) in the lungs and release CO2 (carbon dioxide). This is shown in red in the figure on following page.
In the systemic circulation circuit blood flows from left ventricle to the body and back to the right atrium this allows the blood to pick up CO2 from tissues and release O2. This is shown in blue in the same figure on following page.
When there is a buildup of CO2 in the tissues, such muscles, it forms lactic acid and it is what is called a cramp. Hence the importance of efficient breathing to support a healthy heart during times of physical intensity.
Going more into depth
During physical effort: The rate of oxygen intake increases yielding greater blood supply (systolic blood pressure increases accordingly while diastolic pressure remains relatively constant).
Skeletal arterioles are dilated and the sympathetic influence of the nervous system increases while the parasympathetic influence decreases (refer back to ‘nervous system and breathing’)
With this there is also a direct response from the body with a greater rate of elimination of wastage (heat, water through perspiration, carbon dioxide and lactic acid).
The heart has the capacity to pump anywhere between 5 liters of blood per minute to 35 liters of blood depending on intensity of exercise and fitness level (which includes lung capacity).
Relating it back to Yoga
Asanas that have the most significant influence on the cardiovascular system:
Shirasana (head stand) pressure in the head arteries veins and soft tissues of head and neck is felt. Also physical and psychological pressure such as maintaining balance and urge to come out of posture affecting musculoskeletal nervous endocrine circulatory respiratory and digestive
High blood pressure= blood in arteries and in systemic circulation
Someone active and anxious – the sympathetic nervous system and hormones from the adrenal glands increase blood pressure by increasing both peripheral resistance and the strength and rate of the heartbeat
Blood pressure varies in different parts of the body : increases below heart and decreases above heart for standing blood pressure is equalized only when in a bath or lying supine / when in inverted poses like headstand heart blood pressure stays the same but increases above the heart and decreases below the heart
Pins and needles or go to sleep sensations caused by diastolic blood pressure dropping to 0 and systolic at 40mm Hg insufficient for capillaries to get what they need.
Compare for yourself:
Yogic breathing or NadiShodhan with Jalandhara Bandha and without. Which is easier?