THE SCOPE OF ANATOMY AND PHYSOLOGY

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THE SCOPE OF ANATOMY AND PHYSIOLOGY 

ANATOMY IS THE STUDY OF STRUCTURE WHEREAS PHYSIOLOGY IS THE STUDY OF FUNCTION. LET'S SAY VASODILATION(RELAXATION OF KIDNEYS ARTERIOLES IN RESTING CONDITION) WHICH IS THE PHYSIOLOGY OF KIDNEY(STRUCTURE-ANATOMY) . 

THESE APPROACHES ARE COMPLEMENTARY TO EACH OTHER AND INSEPARABLE. PHYSIOLOGY LENDS TO ANATOMY, CONVERSELY ANATOMY MAKES PHYSIOLOGY POSSIBLE. 

IT CAN BE CONCLUDED THAT UNITY OF FORM AND FUNCTION BECOMES AN IMPORTANT ELEMENT TO KEEP IN MIND WHEN ONE STUDIES BODY. 

ANATOMY-THE STUDY OF FORM

• The simplest way to study human anatomy is the observation of surface structure, for example while performing a physical examination or making a clinical diagnosis from surface appearance.

• A deeper understanding of the body depends on dissection—the careful cutting and separation of tissues to reveal their relationships.

•  Both anatomy and dissection literally mean “cutting apart”; dissecting used to be called “anatomizing.” 

• Many insights into human structure are obtained from comparative anatomy—the study of more than one species in order to learn and compare generalizations and evolutionary trends 

• Students of anatomy often begin by dissecting other animals with which we share a common ancestry and many structural similarities.

• Dissection, of course, can not be applied when studying a living person! Other aspects include Physical examinations which involve not only looking at the body for signs of normalcy or disease but also touching and listening to it.

• Palpation is feeling structure with the fingertips, such as palpating a swollen lymph node or taking a pulse.

• Auscultation is listening to the natural sounds made by the body, such as heart(lub-dub) and lung sounds.

•  In percussion(method of tapping on the body surface during clinical examination), the examiner taps on the body and listens to the sound for signs of abnormalities such as pockets of fluid or air.

• Structure that can be seen with the naked eye, whether by surface observation or dissection, is called gross anatomy.

Ultimately, though, the functions of the body results from its individual cells. To see those, we usually take tissue specimens, thinly slice and stain them, and observe them under the microscope. This approach is called histology-a study of tissues (microscopic anatomy).

•  Histopathology is the microscopic examination of tissues for signs of disease. 

• Ultrastructure refers to fine details, down to the molecular level, revealed by the electron microscope.

Physiology—The Study of Function

Physiology uses the methods of experimental science. It has many sub disciplines such as neurophysiology (physiology of the nervous system),

endocrinology (physiology of hormones), and pathophysiology (mechanisms of disease). 

Partly because of limitations on experimentation with humans, much of what we know about bodily function has been gained through comparative

physiology, the study of how different species have solved problems of life such as water balance, respiration, and reproduction. 

Comparative physiology is also the basis for the development of new drugs and medical procedures. For example, a cardiac surgeon cannot practice

on humans without first succeeding in animal surgery, and a vaccine cannot be used on human subjects until it has been demonstrated through animal research that it confers significant benefits without unacceptable risks.

The Origins of Biomedical Science

Health science has progressed far more in the last 25 years than in the 2,500 years, but the field did not spring up overnight. 

It is built upon centuries of thought and controversy, triumph and defeat. We cannot fully appreciate its present state without understanding its past. 

people who had the curiosity to try new things, the vision to look at human form and function in new ways, and the courage to question authority.

The Beginnings of Medicine

• As early as 3,000 years ago, physicians in Mesopotamia and Egypt treated patients with herbal drugs, salts, physical therapy, and faith healing. 

• The “father of medicine,” however, is usually considered to be the Greek physician Hippocrates (c. 460–c. 375 B.C.E.). 

• He and his followers established a code of ethics for physicians, the Hippocratic Oath, that is still recited in modern form by many graduating medical students. Hippocrates urged physicians to stop attributing disease to the activities of gods and demons and to seek their natural causes, which could afford the only rational basis for therapy. 

• Aristotle (384–322 B.C.E.) believed that diseases and other natural events could have either supernatural causes, which he called theologi, or natural ones, which he called physici or physiology.

•  We derive such terms as physician and physiology  from the latter. Until the nineteenth century, physicians were called “doctors of physic.”

Claudius Galen (129–c. 199), physician to the Roman gladiators, wrote the most noteworthy medical textbook of the ancient era—a book that was worshiped to excess by medical professors for centuries to follow.

• Galen was limited to learning anatomy from what he observed in treating gladiators’ wounds and by dissecting pigs, monkeys, and other animals. Galen saw science as a process of discovery, not as a body of fact to be taken on faith.

The Birth of Modern Medicine

Medical science advanced very little during the Middle Ages. Even though some of the most famous medical schools of Europe were founded during this era, the professors taught medicine primarily as a dogmatic commentary

on Galen and Aristotle, not as a field of original Research

Vesalius broke with tradition by coming down to publish accurate illustrations for teaching anatomy; the first atlas of anatomy, De Humani Corporis Fabrica Anatomy, preceded physiology and was a necessary foundation for it.

Modern medicine Englishman William Harvey (1578–1657) is remembered especially for a little book he published in 1628, On the Motion of the Heart and Blood in Animals. Authorities before him believed that digested

food traveled to the liver, turned into blood, and then traveled through the veins to organs that consumed it. 

Harvey measured cardiac output in snakes and other animals, however, and concluded that the amount of food eaten could not possibly account for so much blood. 

Thus, he inferred that blood must be recycled—pumped out of the heart by way of arteries and returned to the heart by way of veins. Capillaries, the connections between arteries and veins, had not been discovered yet, but Harvey predicted their existence.

 He went on to observe practically everything he could get his hands on, including blood cells, blood capillaries, sperm, and muscular tissue. 

Probably no one in history had looked at nature in such a revolutionary way.

Leeuwenhoek opened the door to an entirely new understanding of human structure and the causes of disease. He was praised at first, and reports of his observations were eagerly received by scientific societies, but this public

enthusiasm did not last.

Leeuwenhoek’s most faithful admirer was the Englishman Robert Hooke (1635–1703), who developed the first practical compound microscope—a tube with a lens at each end. 

The second lens further magnified the image produced by the first.

 Hooke invented many of the features found in microscopes used today: a stage to hold the specimen, an illuminator, and coarse and fine focus controls. His microscopes produced poor images with blurry edges(spherical aberration) and rainbow-colored distortions (chromatic aberration), but poor images were better than none.

 Although Leeuwenhoek was the first to see cells, Hooke named them. In 1663, he observed thin shavings of cork with his microscope and observed that they “consisted of a great many little boxes,” which he called cells after the cubicles of a monastery 

He published these observations in his book, Micrographia, in 1665.

Living in a Revolution

This short history brings us only to the threshold of modern biomedical science; it stops short of such momentous discoveries as the germ theory of disease, the mechanisms of heredity, and the structure of DNA. In the twentieth century, basic biology and biochemistry have given us a much deeper understanding of how the body works.

 Technological advances such as medical imaging have enhanced our diagnostic ability and life-support strategies. 

We have witnessed monumental developments in chemotherapy, immunization, anesthesia, surgery, organ transplants, and human genetics.

 By the close of the twentieth century, we had discovered the chemical “base

sequence” of every human gene and begun using gene therapy to treat children born with diseases recently considered incurable. 

As future historians look back on the turn of this century, they may exult about the Genetic Revolution in which we are now living.

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