Physicians or radiologists then analyze the test results. Radiologists work directly with patients, explaining machinery, preparing them for exams, and ensuring that their body or body parts are positioned correctly to produce the needed images. They produce films or images of the body that help medical professionals examine and diagnose. Some radiography technologists and technicians specialize in computed tomography, MRI, and mammography. This signal is then read by sensors in the machine and interpreted by a computer to form a detailed image.

MRI imaging works by subjecting hydrogen nuclei, which are abundant in the water in soft tissues, to fluctuating magnetic fields, which cause them to emit their own magnetic field. These tests provide data for disease diagnoses by creating images of your organs or skeletal system. Have you or anyone you know ever had a magnetic resonance imaging (MRI) scan, a mammogram, or an X-ray? These tests produce images of your soft tissues and organs (as with an MRI or mammogram) or your bones (as happens in an X-ray) by using either radiowaves or special isotopes (radiolabeled or fluorescently labeled) that are ingested or injected into the body. Reichelt, a radiology technician, as his mock patient to practice his skills in the health clinic at Grafenwoehr Training Area. LaClave practices his spinal X-ray positions utilizing Spc. These weak interactions between molecules are important in biological systems and occur based on physical proximity.įigure 2. Spc. Some of these weak attractions are caused by temporary partial charges formed when electrons move around a nucleus. They occur between polar, covalently bound atoms in different molecules. They are also called inter-molecular forces. Like hydrogen bonds, van der Waals interactions are weak attractions or interactions between molecules. Hydrogen bonds are also responsible for zipping together the DNA double helix.

Individual hydrogen bonds are weak and easily broken however, they occur in very large numbers in water and in organic polymers, creating a major force in combination. This type of bond is common and occurs regularly between water molecules. This interaction is called a hydrogen bond. When this happens, a weak interaction occurs between the δ+ of the hydrogen from one molecule and the δ– charge on the more electronegative atoms of another molecule, usually oxygen or nitrogen, or within the same molecule. Because the hydrogen is slightly positive, it will be attracted to neighboring negative charges. When polar covalent bonds containing hydrogen form, the hydrogen in that bond has a slightly positive charge because hydrogen’s electron is pulled more strongly toward the other element and away from the hydrogen. Hydrogen bonds provide many of the critical, life-sustaining properties of water and also stabilize the structures of proteins and DNA, the building block of cells. Without these two types of bonds, life as we know it would not exist. Two weak bonds that occur frequently are hydrogen bonds and van der Waals interactions.

Weaker bonds can also form between molecules. However, not all bonds are ionic or covalent bonds. Ionic bonds are not as strong as covalent, which determines their behavior in biological systems. Ionic and covalent bonds between elements require energy to break.

Model a hydrogen bond and identify its unique qualities.

Hydrogen bonding