A system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response.A system that provides a defense mechanism to organism, providing defensive measures against antigens which would prove harmful to the organism.
Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and structures inside the body. Health care professionals use it to view the heart, blood vessels, kidneys, liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound does not expose you to radiation. During an ultrasound test, you lie on a table. A special technician or doctor moves a device called a transducer over part of your body. The transducer sends out sound waves, which bounce off the tissues inside your body.
What is an ultrasound? A prenatal ultrasound (also called a sonogram) is a noninvasive diagnostic test that uses sound waves to create a visual image of your baby, placenta, and uterus, as well as other pelvic organs. It allows your healthcare practitioner to gather valuable information about the progress of your pregnancy and your baby's health. During the test, an ultrasound technician (sonographer) transmits high-frequency sound waves through your uterus that bounce off your baby. A computer then translates the echoing sounds into video images that reveal your baby's shape, position, and movements.