8 months I'd say. Maybe longer.
Answer:
B. Oxytocin stimulating increased smooth muscle contraction
Explanation:
Parturition is the process of delivery of the foetus. Vigorous contractions of the uterus at the end of pregnancy causes the delivery of the foetus. It is induced by a complex mechanism which is a neuroendocrine mechanism. It is the fully developed foetus and the placenta which induces or signals the parturition by initiating the mild uterine contractions called foetal ejection reflex. This triggers the release of oxytocin from maternal pituitary gland. Oxytocin then acts on the uterine myometrium (made of smooth muscles) and causes stronger uterine contractions, which in turn stimulates further secretion of oxytocin. This reflex continues resulting in stronger and stronger contractions finally leading to expulsion of the baby out of the uterus through the birth canal.
Answer: I think C (I apologize if not)
Explanation: Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery, and to the lungs.
In the lungs, the blood refills its oxygen supply and gets rid of carbon dioxide. The oxygenated blood returns from the lungs to the left atrium through the pulmonary veins to the heart. The left ventricle then pumps this oxygen-rich blood throughout the body. Blood first enters the heart's right atrium. A muscle contraction forces the blood through the tricuspid valve into the right ventricle. When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery. Then it travels to the lungs.
