Adapted from Medical News Today Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing . Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine . In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and...
Pregnancy occurs when a sperm fertilizes an egg after it’s released from the ovary during ovulation . The fertilized egg then travels down into the uterus , where implantation occurs. A successful implantation results in pregnancy. On average, a full-term pregnancy lasts 40 weeks. There are many factors that can affect a pregnancy. Women who receive an early pregnancy diagnosis and prenatal care are more likely to experience a healthy pregnancy and give birth to a healthy baby. Knowing what to expect during the full pregnancy term is important for monitoring both your health and the health of the baby. If you’d like to prevent pregnancy, there are also effective forms of birth control you should keep in mind. Symptoms of pregnancy You may notice some signs and symptoms before you even take a pregnancy test. Others will appear weeks later, as your hormone levels change . Missed period A missed period is one of the earliest...