1.Red blood cells carry nutrition and oxygen through the capillaries to the tissues. 2. Oxygen is inhaled from the atmosphere to alveoli. 3. Oxygen diffuses into the pulmonary capillaries carried by hemoglobin through the systemic capillaries to the cells. 4. Hemoglobin gives up oxygen and picks up carbon dioxide by diffusion.
Pre-menstrual symptoms (PMS) are the symptoms that a woman may experience one or two weeks before her period begins. PMS is more common in women of age group 30 to 40. About 80% of women experience mild or severe premenstrual symptoms before each period.
I never have been before but it was possible my husband and I conceived because we do not use birth control. I know my body and I have regular periods. I was having symptoms but the biggy was I had light brown spotting for 6 days before my period was due and 12 days past ovulation. On day 6 I had HORRIBLE cramps (I usually get cramps not this bad though) and then some heavy bleeding like a period for a few days.