I. The Scope of Anatomy and Physiology (p. 2)

A. Anatomy—The Study of Form (p. 2)

1. Anatomy is the study of structure, often done by dissection of cadavers. (fig. 1.1)

2. Different levels of anatomy include gross anatomy, microscopic anatomy, and ultrastructure; comparative anatomy examines more than one species.

3. Other ways to study anatomy include palpation, auscultation, and percussion.

B. Physiology—The Study of Function (p. 3)

1. Physiology is the study of function and is primarily an experimental science.

2. Comparative physiology employs other species to enable us to learn more about human physiology.

II. The Origins of Biomedical Science (p. 3)

A. The Beginnings of Medicine (p. 3)

1. Hippocrates (c. 460–c.375 B.C.E.) urged physicians to seek the natural causes of diseases.

2. Aristotle (384–322 B.C.E.) made significant observations about the functioning of the human body and argued that complex structures are built from a smaller variety of simple components.

3. Claudius Galen (129–c.199) was a physician to the Roman gladiators and a careful observer of human anatomy. He viewed science as a way of knowing, a process to be perfected with time.

4. During the Middle Ages, theology dominated human thought. Medicine was taught using Aristotle's and Galen's writings rather than by conducting new research. (fig. 1.2)

B. The Birth of Modern Medicine (p. 3)

1. The Muslim world and Avicenna, or Ibn Sina (980–1037), developed medicine further, beyond what was known by the western world.

2. Flemish physician Andreas Vesalius (1514–64) broke from the tradition of watching cadaver dissections from a cathedra to doing the dissections himself. He pointed out errors in Galen’s book and published the first comprehensive atlas of anatomy. (fig. 1.3)

3. William Harvey was the pioneer in modern physiology. He measured cardiac output and concluded that blood was recycled within the body.

4. Antony van Leeuwenhoek (1632–1703) invented the first microscope and watched microscopic organisms in lake water. He observed numerous types of human tissues and opened the door to an understanding of human structure and the possible causes of disease. (fig. 1.4)

5. Robert Hooke (1635–1703) developed the first compound microscope, including a stage to hold specimens and focusing controls. After viewing cork through it, he coined the name "cells." (fig. 1.5)

6. Carl Zeiss (1818–88) of Germany greatly improved the design of the compound microscope in 1830.

7. Matthias Schleiden (1804–81) and Theodor Schwann (1810–82) developed the cell theory, which stated that all living things were made of cells.

C. Living in a Revolution (p. 6)

1. Monumental strides have been taken during the past century in the fields of immunization, chemotherapy, surgery, anesthesia, organ transplants, and human genetics.

III. Scientific Method (p. 7)

A. The Inductive Method (p. 7)

1. The inductive method involves making numerous observations and drawing generalizations and predictions.

B. The Hypothetico–Deductive Method (p. 7)

1. The hypothetico-deductive method begins with formulating a hypothesis and then making a deduction. An experiment can help the scientist decide whether to abandon the hypothesis.

C. Experimental Design (p. 8)

1. Experimental design must employ a large enough sample size and a control group. The control group receives the same conditions as the treatment group, with the exception of the variable under observation.

2. Placebos are used to rule out psychosomatic effects in medication trials.

3. Experimenter bias can be minimized by using the double-blind method, in which neither the physician nor the patient knows which treatment is received; only the scientist in charge knows.

4. Experiments must undergo rigorous statistical testing to help rule out chance events.

D. Peer Review (p. 8)

1. Most scientific journals subject manuscripts to rigorous peer review prior to publication.

E. Facts, Laws, and Theories (p. 9)

1. Basic research involves determining how nature works, and our understanding of this is expressed as facts, laws, and theories.

2. A scientific fact is an observation; a law of nature is a generalization supported by much scientific evidence. A theory is a well-substantiated statement designed to explain a natural phenomenon.

IV. Human Evolution (p. 9)

A. Evolution, Selection, and Adaptation (p. 10)

1. The ideas of Charles Darwin were pivotal in the development of evolutionary theory. He formed the theory of natural selection, which proposed a mechanism for evolution. (fig. 1.6)

2. Evolution refers to the genetic change that occurs in populations over time, as influenced by selection pressures. An organism’s individual adaptations enable it to survive.

3. Recent DNA evidence for evolution supports the ideas of Darwin. Chimpanzees are man's closest living relative, differing in only 1.6% of their DNA compared to human DNA.

4. Although they are less closely related to humans, laboratory rats and mice make a good model for human disease.

B. Life in the Trees (p. 10)

1. Primates originated as tree-dwellers 55–60 million years ago. Prehensile hands and stereoscopic vision, along with color vision, also helped make possible an arboreal life. (figs. 1.7, 1.8; TR 1)

2. Humans and apes at one point shared a common ancestor. Humans did not evolve from apes. (fig. 1.9; TR 2)

C. Walking Upright (p. 12)

1. Africa became drier 4–5 million years ago, and much of the tropical forest was replaced by grassland. Certain primates began standing on hind legs to search for predators. Over time, bipedalism and coincident skeletal changes emerged.

V. The Nature of Human Life (p. 12)

A. What Is Life? (p. 13)

1. Life is a collection of properties, such as organization, cellular composition, biochemical unity, metabolism, responsiveness, homeostasis, development, growth, reproduction, and evolution.

2. Clinical and legal definitions of life vary from those of the scientist. A person is declared legally dead when he/she has not shown brain waves for 30 minutes, has no reflexes, and has no heartbeat or respiration without assistance.

B. What Is a Human? (p. 14; fig. 1.10; TR 3 )

1. Humans’ animal characteristics place them within the kingdom Animalia. As such, they are multicellular eukaryotes, have heterotrophic nutrition, and are responsive because of muscle and nerve cells.

2. Humans belong in the phylum Chordata because during development they possess a notochord, a dorsal hollow nerve cord, pharyngeal gill pouches, and a postanal tail. (fig. 1.11)

3. Humans belong to the subphylum Vertebrata because they have an internal skeleton, a jointed vertebral column, a cranium, and a well-developed brain and sense organs.

4. Humans are placed in the class Mammalia because of mammary glands, hair, endothermy, heterodonty, a single jawbone, and three middle-ear bones.

5. Humans belong to the order Primates along with the apes and monkeys because of the arrangement of their incisors, two clavicles, only two mammary glands, pendulous penis, forward-facing eyes, flat nails, and opposable thumbs.

6. Humans belong to the family Hominidae, the bipedal primates. Modern Homo sapiens is the only surviving species. (table 1.1)

C. Human Structure—A Hierarchy of Complexity (p. 17; fig. 1.12; TR 4))

1. The structural hierarchy of the human body begins at the subatomic level and progresses through the levels of atoms, molecules, organelles, cells, tissues, organs, and finally, organ systems.

2. Reductionism suggests that a human body can be understood by studying its simpler components.

3. Holism suggests that properties possessed by the whole organism are not apparent from the study of its parts—for example, psychological factors.

VI. Homeostasis and Feedback (p. 19)

A. Homeostasis (p. 19)

1. Homeostasis is the body's ability to maintain relatively constant internal conditions and to return to those conditions if upset.

B. Negative Feedback and Stability (p. 19)

1. Negative feedback is the main way the body returns to stable conditions. The way a thermostat controls a room's temperature illustrates the process of negative feedback. (figs. 1.13, 1.14; TR 5, 6)

2. In the case of body temperature, human "thermostats" involve vasoconstriction or vasodilation of blood vessels to exchange heat with the outside environment.

C. Positive Feedback and Rapid Change (p. 20)

1. Positive feedback is a self-amplifying cycle; an example is the output of oxytocin and the stimulation of uterine contractions during labor and childbirth. (fig. 1.15; TR 7)

2. Some pathogens trigger high fevers that are regulated by positive feedback designed to rid the body of the pathogen. This type of positive feedback can be life-threatening. (fig. 1.16; TR 8)

VII. Review of Major Themes (p. 21)

A. Major themes considered during the study of human anatomy and physiology include cell theory, homeostasis, evolution, hierarchy of structure, and unity of form and function.