Anatomy and Physiology For Dummies

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Atoms are made up of the subatomic particles protons and neutrons, which are in the atom’s nucleus, and clouds of electrons orbiting the nucleus. The atomic weight, or mass, of an atom is the total number of protons and neutrons in its nucleus. The atomic number of an atom is its number of protons; conveniently, atoms that are electrically neutral have the same number of positive charges as negative charges. Thoracic cavity:The chest or thorax; contains the heart, lungs, and their associated structures, as well as the esophagus and several glands An organ is a part of the body that performs a specialized physiological function. For example, the stomach is an organ that has the specific physiological function of breaking down food. By definition, an organ is made up of at least two different tissue types; many organs contain tissues of all four types. Although we can name and describe all four tissue types that make up all organs, as we do in the preceding section, listing all the organs in the body wouldn’t be so easy.

Following are ten key things you can start doing today to ensure success not only in anatomy and physiology but in any number of other classes. Write down important stuff in your own words If you examine a sample of any human tissue under a microscope, you see cells, possibly millions of cells. All living things are made of cells. In fact, having a cellular level of organization is inherent in any definition of organism. We discuss the cellular level of organization in some detail in Chapter 3. Level II: The tissue level Abdominal cavity: Contains the stomach, liver, gallbladder, pancreas, spleen, small intestines, and most of the large intestineThe respiratory system helps in gas exchange by taking in oxygen from the air and expelling carbon dioxide from the body. Air enters the nose and mouth and travels through the larynx, or voice box, and trachea, or windpipe. At the lungs, the trachea branches to form two bronchi (singular, bronchus); each bronchus enters one of the lungs. In the lungs the bronchi branch further, forming smaller airways called bronchioles, which further divide many times to form a very large number of small air spaces called alveoli. This workbook isn’t a substitute for a textbook, and it is certainly not meant to replace going to an actual anatomy and physiology class. If you remove all the internal organs, the body is empty except for the bones and tissues that form the space where the organs were. Just as a dental cavity is a hole in a tooth, the body’s cavities are holes where organs are held (see Figure 1-3). The two main cavities are the dorsal cavity and the ventral cavity.

The following list of common anatomical descriptive terms that appear throughout this and every other anatomy book may come in handy: Figure 1-4: Levels of organization in the human body. 9780470923269-fg0104.eps Level I: The cellular level Darwin made scientific history in his own way, of course, but it was a German physicist named Wilhelm Conrad Roentgen who’s remembered as the father of medical imaging. In 1895, Roentgen recorded the first image of the internal parts of a living human: an X-ray image of his wife’s hand. By 1900, X-rays were in widespread use for the early detection of tuberculosis, at that time a common cause of death. X-rays are beams of radiation emitted from a machine toward the patient’s body, and X-ray images show details only of hard tissues, like bone, that reflect the radiation. In this way, they’re similar to photographs. Refinements and enhancements of X-ray techniques were developed all through the 20th century, with extensive use and major advances during World War II. The X-ray is still a widely used method for medical diagnosis screening for signs of disease, usually tumors. Dorsal cavity: Bones of the cranial portion of the skull and vertebral column, toward the posterior (dorsal) side of the body Ventral cavity:Anterior portion of the torso; divided by the diaphragm into the thoracic cavity and abdominopelvic cavityWhy does science have so many funny words? Why can’t scientists just say what they mean, in plain English? Good question, with short and long answers. Creating better communication The fourth shell (which can be found in elements such as potassium, calcium, and iron) holds up to 18 electrons. Higher shells also exist. Species Sapiens: All species are given a two-part Latin name, in which the genus name comes first and a species epithet comes second. The biologists who name species sometimes try to use a descriptor in the epithet. For humans, they could have chosen bipedal or talking or hairless, but they chose thinker. A key endocrine gland is the pituitary, which is located under the brain in the middle of the head. It produces at least eight hormones, which affect growth, kidney function, and development of the gonads, or sex organs. Because some of the pituitary’s hormones stimulate other glands to produce their own hormones, the pituitary is called the master gland. Erin Odya teaches Anatomy & Physiology at Carmel High School in Carmel, Indiana, one of Indiana's top schools. She is also the author of Anatomy & Physiology For Dummies.