Auscultation

(AWS-cul-TAY-shun)

Dissection

Careful cutting and separation of tissues to reviel their relationships.

Histology

(microscopic anatomy)

400-C 375 BC

Considered the father of medicine

He and his followers established a code of ethics, Hippocratic Oath, that is still recited by modern physicians.

Aristolte

344-322 BCE

Theologi

(Aristotle)

Physici or Physiologi

Aristotle

Claudius Galen

130-c-200

Moses ben Maimon

(1135-1204)

Known as Maimonides

Ibn Sina

9980-1037)

Known as Avicenna or Galen of Islam

Andreas Vesalius

(1514–64) 

taught anatomy in Italy.In his time, the Catholic Church relaxed its prohibition against cadaver dissection, primarily to allow autopsies in cases of suspicious death. Dissections were conducted outdoors in a nonstop 4-day race against decay. barber–surgeon removed putrefying organs from the cadaver and held them up for the students to see. Barbering and surgery were considered to be “kindred arts of the knife”; today’s barber poles date from this era, their red and white stripes symbolizing blood and bandages. 

 Vesalius broke with tradition by coming down from the cathedra and doing the dissections himself. He was quick to point out that much of the anatomy in Galen’s books was wrong, and he was the first to publish accurate 

illustrations for teaching anatomy (fig. 1.3). When others began to plagiarize his illustrations, Vesalius published the first atlas of anatomy, De Humani Corporis Fabrica (On the Structure of the Human Body), in 1543. This book began a rich tradition of medical illustration that has been handed down to us through such milestones as Gray’s Anatomy (1856) and the vividly illustrated atlases and textbooks of today.

William Harvey

(1578–1657)

What Vesalius was to anatomy, Harvey was to physiology.

Michael Servetus

(1511–53) 

along with Harvey

...were the first Western scientists to realize that blood must circulate continuously around the body, from the heart to the other organs and back to the heart again. This flew in the face of Galen’s belief that the liver converted 

food to blood, the heart pumped blood through the veins to all other organs, and those organs consumed it.

Robert Hooke

(1635–1703)

an Englishman

designed scientific instruments of various kinds and made many improvements in the compound microscope. This is a tube with a lens at each end. Hooke improved the optics and invented several of the helpful features found in 

microscopes today—a stage to hold the specimen, an illuminator, and coarse and fine focus controls. His microscopes magnified only about 30 times, but with them, he was the first to see and name cells. He published the first comprehensive book of microscopy, Micrographia, in 1665.

Microscope

objective lens

Microscope

ocular lens (eyepiece)

near the observer’s eye, which magni-

fies the first image still further.

Antony van Leeuwenhoek

(an-TOE-nee vahn LAY-wen-hook)

(1632–1723)

a Dutch textile merchant

invented a simple (single-lens) microscope, originally for the purpose of 

examining the weave of fabrics. His microscope was a bead-like lens mounted in a metal plate equipped with a movable specimen clip. Even though his microscopes were simpler than Hooke’s, they achieved much greater useful magnification (up to 200 ! )  owing to Leeuwenhoek’s superior lens-grinding skill. 

Carl Zeiss

(1816–88) 

German

 Ernst Abbe

(1840–1905)

physicist

partner of Carl Zeiss

Matthias Schleiden

(1804–81)

botanist 

concluded that all organisms were composed of cells. Although it took another century for 

this idea to be generally accepted, it became the first tenet of the cell theory, added to by  later biologists

Theodor Schwann

(1810–82) 

zoologist 

The cell theory was perhaps the most impor-

tant breakthrough in biomedical history; all functions of the body are now interpreted as the effects of cellular activity.

Francis Bacon

(1561–1626)

English philosopher

envisioned science as a far greater, systematic enterprise with enormous possibilities for human health and welfare. He detested those who endlessly debated ancient philosophy without creating anything new. Bacon argued against biased thinking and for more objectivity in science. He outlined a systematic way of seeking similarities, differences, and trends in nature and drawing useful generalizations from observable facts. He is credited with putting science on the path to modernity, not by discovering anything new in nature or 

inventing any techniques—for neither man was a scientist—but by inventing new habits of scientific thought.

 René Descartes

(1596–1650)

French philosopher

envisioned science as a far greater, systematic enterprise with enormous possibilities for human health and welfare. He detested those who endlessly debated ancient philosophy without creating anything new. Bacon argued against biased thinking and for more objectivity in science. He outlined a systematic way of seeking similarities, differences, and trends in nature and drawing useful generalizations from observable facts. He is credited with putting science on the path to modernity, not by discovering anything new in nature or 

inventing any techniques—for neither man was a scientist—but by inventing new habits of scientific thought

refers less to observational procedures than to certain habits of disciplined creativity, careful observation, logical thinking, and honest analysis 

of one’s observations and conclusions. It is especially important in health science to understand these habits.

first prescribed by Bacon, is a process of making numerous observations until one feels confident in drawing generalizations and predictions from them.

if it was arrived at by reliable methods of observation, tested and confirmed 

repeatedly, and not falsified by any credible observation. 

An investigator begins by asking a question and formulating a hypothesis—an

educated speculation or possible answer to the question. A good hypothesis must be (1) consistent with what is already known and (2) capable of being tested and possibly falsified by evidence. Falsifiability means that if we claim 

something is scientifically true, we must be able to specify what evidence it would take to prove it wrong. If nothing could possibly prove it wrong, then it is not scientific.

must be (1) consistent with what is already known and (2) capable of being tested and possibly falsified by evidence. The purpose of a hypothesis is to suggest a method for answer ing a question. From the hypothesis, a 

researcher makes a deduction, typically in the form of an “if-then” prediction: If my hypothesis on epilepsy is correct and I record the brain waves of patients during seizures, then I should observe abnormal bursts of  activity. Hypothesis testing operates in cycles of conjecture and disproof until one is found that is supported by the evidence.

means that if we claim something is scientifically true, we must be able to specify what evidence it would take to prove it wrong. If nothing could possibly prove it wrong, then it is not scientific.

Sample size, Controls, Psychosomatic effects, placebo, Experimenter bias, double-blind method, Statistical testing, 

The number of subjects (animals or people) used in a study is the sample size. An adequate sample size controls for chance events and individual variations in response and thus enables us to place more confidence in the outcome. For 

example, would you rather trust your health to a drug that was tested on 5 people or one tested on 5,000? 

 Biomedical experiments require comparison between treated and untreated individuals so that we can judge whether the treatment has any effect. 

A control group consists of subjects that are as much like the treatment group as possible except with respect to the variable being tested.

(effects of the subject’s state of mind on his or her physiology) can have an undesirable effect on experimental results if we do not control for them. 

placebo

(pla-SEE-bo)

experimenters may want certain results so much that their biases, even subconscious ones, can affect their interpretation of the data.

neither the subject to whom a treatment is given nor the person giving it and recording the results knows whether that subject is receiving the experimental treatment or placebo. 

 Perhaps you have heard of the chi-square test, the t test, or analysis of variance, for example. 

a critical 

evaluation by other experts in that field

a generalization about the predictable ways in which matter and energy behave. It is the result of inductive reasoning based on repeated, confirmed observations. 

expressed as mathematical formulae. (BL) used in respiratory physiology: Under speci-

fied conditions, the volume of a gas (V) is inversely proportional to its pressure (P)—V µ 1/P.

explanatory statement or set of  statements 

derived from facts, laws, and confirmed hypotheses. 

In common usage, a law is a rule created and enforced by people; we must obey it or risk a penalty. A law of nature, however, is a description; laws do not govern the universe, they describe it.

an explanation of how species originate and change through time, was the brainchild of Charles Darwin (1809–82)—probably the most influential biolo

gist who ever lived. His book, On the Origin of Species by Means of Natural Selection (1859), has been called “the book that shook the world.” On the Origin of Species scarcely touched upon human biology, but its unmistakable implications for humans created an intense storm of controversy that continues even today. In The Descent of Man (1871), Darwin directly addressed the issue of human evolution and emphasized features of anatomy and behavior that reveal our relationship to other animals. No understanding of human form and function is complete without an understanding of our evolutionary history.

change in the genetic composition of a population of organisms. Examples include the evolution of bacterial resistance to antibiotics, the appear-

ance of new strains of the AIDS virus, and the emergence of new species of organisms.

the principal theory of how evolution works. It states essentially this: Some individuals within a species have hereditary advantages over their 

competitors—for example, better camouflage, disease resistance, or ability to attract mates—that enable them to produce more offspring. They pass these advantages on to their offspring, and such characteristics therefore become 

more and more common in successive generations. This brings about the genetic change in a population that constitutes evolution.

Natural forces that promote the reproductive success of some individuals more than others. They include such things as climate, predators, disease, competition, and the availability of food.  

eatures of an organism’s anatomy, physiology, and behavior that have evolved in response to 

these selection pressures and enable the organism to cope with the challenges of its environment. 

suggests a difference of only 1.6% in DNA structure between humans and chimpanzees. Chimpanzees and gorillas differ by 2.3%. DNA structure suggests that a chimpanzee’s closest living relative is not the gorilla or any other ape—

it is us.

An animal species or strain selected for research on a particular problem 

treetop habitat

Opposable

(thumbs)

cross the palm to touch the fingertips—and enabled primates to hold small objects and 

manipulate them more precisely than other mammals can

able to grasp branches by encircling them with the thumb and fingers (fig. 1.5). The thumb is so important that it receives highest priority in the repair of hand injuries. If the thumb can be saved, the hand can be reasonably functional; if it is lost, hand functions are severely diminished.

Stereoscopic vision 

stereo = solid + scop = vision

depth perception This adaptation provided better 

hand–eye coordination in catching and manipulating prey, with the added advantage of making it easier to judge distances accurately in leaping from tree to tree. 

Bipedalism

bi = two + ped = foot

standing and walking on two legs.

Fossil evidence indicates that bipedalism was firmly established more than 4 million years ago

Genus

Australopithecus

(aus-TRAL-oh-PITH-eh-cus)

Genus

Homo

About 2.5 million years ago, hominids appeared with taller stature, greater brain volumes, simple stone tools, and probably articulate speech

originated in Africa about 200,000 years ago and is the sole surviving hominid species.

Our own species, Homo sapiens, has been notoriously difficult to define. Some authorities apply this name to various forms of “archaic Homo” dated as far back as 600,000 years, whereas others limit it to anatomically 

modern humans no more than 200,000 years old. Several other species of Homo between Homo erectus and modern Homo sapiens have been named in recent decades; their naming, classification, and relationships are still 

a matter of considerable debate.

 Evolutionary

(darwinian) medicine 

Humans have an 

analogous hierarchy of complexity, as follows (fig. 1.7):

The organism is composed of organ systems,

organ systems are composed of organs,

 organs are composed of tissues,

  tissues are composed of cells,

   cells are composed partly of organelles,

    organelles are composed of molecules, and

     molecules are composed of atoms.

a group of organs with a unique collective function, such as circulation, respiration, or digestion. The human body has 11 organ systems, illustrated in atlas A immediately following this chapter: the integumentary, skel-

etal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, urinary, digestive, and reproductive systems. Usually, the organs of one system are physically interconnected, such as the kidneys, ureters, urinary bladder, and 

urethra, which compose the urinary system.

a structure composed of two or more tissue types that work together to carry out a particular function. Organs have definite anatomical boundaries 

and are visibly distinguishable from adjacent structures. Most organs and higher levels of structure are within the domain of gross anatomy. However, there are organs within organs—the large organs visible to the naked eye 

often contain smaller organs visible only with the microscope. The skin, for example, is the body’s largest organ. Included within it are thousands of smaller organs: each hair, nail, gland, nerve, and blood vessel of the skin is an organ in itself. A single organ can belong to two organ systems. For example, the pancreas belongs to both the endocrine and digestive systems.

a mass of similar cells and cell products 

that forms a discrete region of an organ and performs a specific function. The body is composed of only four primary classes of tissue: epithelial, connective, nervous, and muscular tissue. 

he smallest units of an organism that carry out all the basic functions of life; nothing simpler than a cell is considered alive. A cell is enclosed in a plasma membrane composed of lipids and proteins. Most cells have one nucleus, an organelle that contains its DNA. 

microscopic structures in a cell that carry out its individual functions. Examples include mitochondria, centrioles, and lysosomes.

largest molecules, such as proteins, fats, 

and DNA,

the smallest particles 

with unique chemical identities.

the complementary theory that there are “emergent properties” of 

the whole organism that cannot be predicted from the properties of its separate parts—human beings are more than the sum of their parts. To be most effective, a health-care provider treats not merely a disease or an 

organ system, but a whole person. A patient’s perceptions, emotional responses to life, and confidence in the nurse, therapist, or physician profoundly affect the outcome of treatment. In fact, these psychological factors often play a greater role in a patient’s recovery than the physical treatments administered.

In most people, the spleen, pancreas, sigmoid colon, and most of the heart are on the left, while the appendix, gallbladder, and most of the liver are on the right. The normal arrangement of these and other internal organs 

selective right-left reversal of 

the heart

Organization, Cellular composition, Metabolism, Responsiveness and movement, Homeostasis, Development, Reproduction, Evolution.

Living things exhibit a far higher 

level of organization than the nonliving world 

around them. They expend a great deal of energy

to maintain order, and a breakdown in this order 

is accompanied by disease and often death.

Living matter is always 

compartmentalized into one or more cells.

Living things take in molecules from the environment and chemically change them into molecules that form their own structures, control their physiology, or provide them with energy. Metabolism is the sum of all this internal chemical change. It consists of two classes of reactions: anabolism,16 in which relatively complex molecules are synthesized from simpler ones (for example, protein synthesis), and catabolism,17in which relatively complex molecules are broken down into simpler ones (for example, protein diges-

tion). Metabolism inevitably produces chemical wastes, some of which are toxic if they accumulate. Metabolism therefore requires excretion, the separation of wastes from the tissues and their  elimination from the body. There is a constant turnover of molecules in the body; few of the molecules now in your body have been there for more than a year. It is food for thought that although you sense a continuity of personality and experience from your childhood to the present, nearly all of your body has been replaced within the past year.

The ability of organisms to sense and react to stimuli (changes in their 

environment) is called responsiveness, irritability, or excitability. It occurs at all levels from the single cell to the entire body, and it characterizes all living 

things from bacteria to you. Responsiveness is especially obvious in animals because of nerve and muscle cells that exhibit high sensitivity to environ-

mental stimuli, rapid transmission of information, and quick reactions. Most living organisms are capable of self-propelled movement from place to place, and all organisms and cells are at least capable of moving substances internally, such as moving food along the digestive tract or moving molecules and organelles from place to place within a cell.

Any change in form or function over the lifetime of the organism. In most organisms, it involves two major processes: 

(1) differentiation, the transformation of cells with no specialized function into cells that are committed to a particular task, and

(2) growth, an increase in size. Some 

nonliving things grow, but not in the way your body does.

the transformation of cells with no 

specialized function into cells that are committed to a particular task

 genetic change from generation to generation. This occurs because mutations (changes in DNA structure) are inevitable and because environmental selection pressures endow some individuals with greater reproductive success than others. 

Physiological variables differ with sex, age, weight, diet, degree of physical activity, and environment, among other things. Failure to consider such variation leads to medical 

mistakes such as overmedication of the elderly or medicating women on the basis of research that was done on men. 

defined as a healthy male 22 years old, weighing 70 kg (154 lb), living at a mean ambient 

(surrounding) temperature of 20°C, engaging in light physical activity, and  consuming 2,800 kilocalories (kcal) per day. 

same as a reference man except  for a weight 

of 58 kg (128 lb) and an intake of 2,000 kcal/day.

Homeostasis

(HO-me-oh-STAY-sis)

the body’s ability to detect change, activate mechanisms that oppose it, and 

thereby maintain relatively stable internal conditions.

Claude Bernard

(1813–78)

French physiologist

Walter Cannon

(1871–1945) 

American physiologist

 average value for a given variable (such as 37°C for body temperature) and conditions fluctuate slightly around this point.

The fundamental mechanism that keeps a variable close to its set point. a process in 

which the body senses a change and activates mechanisms that negate or reverse it. By maintaining stability, negative feedback is the key mechanism for maintaining health.

feedback mechanisms that alter the original 

changes that triggered them 

Vasodilation

(VAY-zo-dy-LAY-shun)

a narrowing of the blood vessels in the skin, which serves to retain warm blood deeper in your body and reduce heat loss. If this is not enough, the brain activates shivering—muscle tremors that generate heat.

sensory nerve endings in the large arteries 

near the heart.

nerve signals to the brainstem, that regulates the 

heart rate.

a structure that senses a 

change in the body

a mechanism that processes this information, relates it to other available information (for example, comparing what the blood pressure is with what it should be), and “makes a decision” about what the appropriate response should be. 

the cell or organ that carries out the final cor-

rective action

a self-amplifying cycle in which a physiological change leads to even greater change in the same direction, rather than producing the corrective 

effects of negative feedback.

a small fibrous band 

near the heart

Terminologia Anatomica

(TA)

The TA was codified in 1998 by an international body of anatomists, the Federative Committee on Anatomical Terminology, and approved by professional associations of anatomists in more than 50 countries

Nomina Anatomica 

(NA)

Scientific terms are typically composed of one or 

more of the following elements:

At least one root (stem) that bears the core meaning of the word. Combining vowels that are often inserted to join roots and make the word easier to pronounce.A prefix may be present to modify the core meaning 

of the word.A suffix may be added to the end of a word to modify 

its core meaning.