Mixing chemicals with waste in sewage holding tanks or septic. systems may produce toxic fumes, corrode pipelines and tanks, and. pollute soil and ground water when discharged. When chemicals, such as formaldehyde, are added to septic systems, they can cause. bacteria in the system to die.
The cervix is the opening to the womb. Itâs located between the vagina and the uterus and plays a crucial role in pregnancy and labor. During pregnancy, it remains closed and the opening is blocked with a mucus plug.
The cervix (or neck of the uterus) is the link between the uterus and the vagina (or birth canal) and is found at the top of the vagina. It is a firm, smooth, rounded structure with a central opening which: 1  dilates (opens up) during labour. 2  allows menstrual blood to flow through it during your periods.hen youâre not pregnant, your uterus is approximately pear-sized. It has a thick muscular wall and a central cavity with a lining that is richly supplied with blood vessels. This lining is known as the endometrium and it provides nourishment for the embryo during the very early days of life.