The right ventricle then pumps blood through the pulmonary artery into the lungs. 4. In the lungs, tiny blood vessels called capillaries absorb carbon diox-ide from the blood and replace it with oxygen. 5. Oxygenated blood then flows through the pulmonary vein and into the left atrium. 6.
It is this hormone progesterone that can affect your digestive system by delaying the transit time of food through the intestines and hence may lead to constipation before your period. Usually though, you should find that the period-related constipation eases with the start of menstruation.
Constipation is generally described as having fewer than three bowel movements a week. Though occasional constipation is very common, some people experience chronic constipation that can interfere with their ability to go about their daily tasks. Chronic constipation may also cause excessive straining to have a bowel movement and other signs and symptoms. Treatment for chronic constipation depends in part on the underlying cause. However, in some cases, a cause is never found. Chronic constipation care at Mayo Clinic.