Saladin 5e Extended Outline

Chapter 1

Major Themes of Anatomy and Physiology

I. The Scope of Anatomy and Physiology (pp. 2–3)

A. Anatomy is the study of form (pp. 2–3) (Fig. 1.1)

1. Anatomy and dissection both mean cutting apart, and dissection is essential for study.

2. Comparative anatomy studies bodies of more than one species.

3. Exploratory surgery has now been largely replaced by medical imaging.

4. Radiology is the branch of medicine concerned with imaging.

5. Gross anatomy involves structures that can be seen with the naked eye.

6. Histology is the observation of tissue specimens microscopically.

a. Histopathology is studying tissue for signs of disease.

b. Ultrastructure is the fine detail of tissue revealed by the electron microscope.

B. Physiology is the study of function (p. 3)

1. Physiology has many subdisciplines that study specific systems or disease in general.

2. Comparative physiology is the study of biological functions of different species.

3. Comparative physiology is often the basis of new drugs and new procedures.

II. The Origins of Biomedical Science (pp. 3–6)

A. The Greek and Roman legacy begins with Hippocrates (p. 3)

1. Hippocrates, in Greece ca. 400 BCE, is considered the “father of medicine.”

2. Aristotle, in Greece ca. 350 BCE, tried to identify unifying themes in nature.

3. Galen, in Rome ca. 160 CE, wrote the most noteworthy medical text of his time.

B. Modern medicine began in the Middle Ages and continues to the present (p. 4–6) (Fig. 1.2)

1. The Christian culture of Europe in the Middle Ages severely repressed scientific study.

2. Rabbi Moses ben Maimon (Maimonides), ca. 1180 CE, wrote 10 medical texts.

3. Ibn Sina (Avicenna), ca. 1000 CE, wrote The Canon of Medicine, which was the leading text in Europe for 600 years.

4. In China, medical arts evolved independently of those of Europe.

5. Modern Western medicine began in the sixteenth century when the Catholic Church relaxed rules against dissection.

a. Andreas Vesalius, ca. 1530 CE, taught anatomy and was able to conduct autopsies. (Fig. 1.3)

i. Vesalius found that much of the anatomy of Galen was wrong.

ii. Vesalius published the first atlas of anatomy in 1543.

b. William Harvey, ca. 1630 CE, was to physiology what Vesalius was to anatomy.

i. Harvey and Michael Servetus discovered the continuous circulation of blood.

c. Robert Hooke, ca. 1670 CE, designed microscopes and was able to view cells. (Fig. 1.4)

d. Antony van Leeuwenhoek, ca. 1365, improved the magnification of microscopes to about 200X.

e. Carl Zeiss and Ernst Abbe, in the mid-1800s, improved the compound microscope.

f. Schleiden and Schwann, also in the mid-1800s. set forth the cell theory—that all organisms were composed of cells.

6. Until the twentieth century, medicine was not practiced by physicians trained in scientific disciplines.

C. The twentieth century has been a time of medical revolution, and the twenty-first century promises further advances in genetics and technology (p. 6)

III. The Scientific Method (pp. 7–9)

A. In the 1600s in Europe, Francis Bacon and Rene Descartes viewed science as capable of becoming a systematic method of study that would have enormous implications for human health and welfare. (p. 7)

B. The scientific method is a combination of disciplined creativity, careful observation, logical thinking, and honest analysis. (p. 7)

C. The inductive method involves making numerous observations and drawing a generalization from them. (p. 7)

1. Anatomy is a product of the inductive method.

D. The hypothetico-inductive method involves formulating a hypothesis, a possible answer to the question, and then making observations or performing tests to support or refute the hypothesis. (p. 7)

E. Proper experimental design helps ensure that results obtained are not biased in some way. (p. 8)

1. An adequately large sample size allows greater confidence in results.

2. Control groups help ensure that observed differences are due to the factors being tested.

3. Use of placebo substances helps to eliminate psychosomatic effects of treatment differences.

4. The double-blind method guards against experimenter bias by hiding the identity of the treatment groups versus control groups.

5. Statistical testing allows evaluation of whether a result has occurred simply by chance.

F. Peer review is evaluation of a completed project by other experts in the field to help ensure honesty, objectivity, and quality of research. (p. 8)

G. A scientific fact is information that can be independently verified by any trained person. (p. 9)

H. A law of nature is a generalization about the ways in which matter and energy behave. (p. 9)

1. Some laws are expressed as verbal statement, such as the law of complementary base-pairing in DNA.

2. Other laws are expressed as mathematical formulae, such as Boyle’s law about the inverse relation of gas volume to pressure.

I. A theory is a statement or set of statements derived from facts, laws, and confirmed hypotheses, such as the cell theory, the fluid mosaic theory of membranes, and the sliding filament theory of muscle contraction. (p. 9)

4. The terms law and theory have different meaning in science than in common usage.

a. A law of nature is a description; laws do not “govern” the universe.

b. Scientists use the word hypothesis for what in common usage is termed a theory.

c. The different usages can be confusing when people conclude that something like evolution is “just a theory,” meaning a guess or conjecture.

IV. Human Origins and Adaptations (pp. 9–12)

A. The cell theory and the theory of natural selection have broad implications for human origins and understanding the human body. (p. 9)

1. Charles Darwin’s book On the Origin of Species by Means of Natural Selection (1859) presented the first well-supported theory of evolution.

2. In The Descent of Man (1871) Darwin addressed the issue of human evolution.

B. Evolution means the change in the genetic composition of a population of organisms. (p. 10)

C. Natural selection is the principle theory of how evolution works. (p. 10)

1. Some individuals have hereditary advantages of competitors that allow them to produce more offspring, thus increasing their characteristics in a population.

2. Selection pressures are forces such as climate, predators, disease, competition, and the availability of food.

3. Adaptations are features of an organism that have evolved in response to selection pressures.

4. The DNA of humans has a difference of only 1.6% compared to that of chimpanzees on the basis of hybridization studies.

5. Our evolutionary relationship to other species makes possible the testing of drugs on other species, especially those considered closer to us.

a. An animal species selected for research on a question is termed a model.

D. Humans belong to an order of mammals called Primates, which also includes monkeys and apes. (pp. 10–11)

1. The earliest primates were descended from squirrel-sized insectivores that lived in trees 60 million years ago.

2. The shoulder of these early primates adapted to become more mobile, allowing reaching in any direction.

a. Arboreal animals also developed fully opposable thumbs that made hands prehensile, or able to grasp branches. (Fig. 1.5)

Insight 1.1 Vestiges of Human Evolution

3. Eyes of primates became more forward-facing, allowing for stereoscopic vision. (Fig. 1.6)

4. Color vision, rare in mammals, also evolved in primates.

a. Color vision allowed identification of ripe fruits and tender, young leaves.

5. Humans did not evolve from monkeys or apes, but from a common ancestor.

E. Four to five million years ago, primates living on savanna (grasslands) evolved adaptations that allowed them to walk upright. (pp. 11–12)

1. Bipedalism means standing and walking on two legs, and adaptations of the feet, legs, pelvis, spine, skull and arms were necessary. (Table 1.1)

a. Fossil footprints have been found of bipedal primates dating to 3.6 million years ago.

2. Brain volume increased dramatically as adaptations for bipedalism occurred.

a. Increased skull size would make birth difficult and may explain why human infants are born in an immature state.

b. Helplessness of young increased the need for parental care and may explain the development of family ties.

3. The oldest bipedal primates were in the genus Australopithecus.

4. About 2.5 million years ago, the genus Homo arose.

a. Homo erectus migrated from Africa to parts of Asia about 1.8 million years ago.

b. Homo sapiens originated in Africa about 200,000 years ago, and is the sole surviving hominid species. (Fig. 1.7)

5. Homo sapiens has been difficult to define, and naming and classification is still a matter of debate.

F. Evolutionary medicine is an emerging science that uses an evolutionary perspective to view medical conditions and diseases. (p. 12)

V. Human Structure (pp. 13–15)

A. Humans exhibit a hierarchy of complexity in body structures. (pp. 13–14) (Fig. 1.8)

1. The organism is a single, complete individual.

2. An organ system is a group of organs with a unique collective function.

a. Examples of organ systems include circulation, respiration, and digestion.

b. The human body has 11 organ systems.

3. An organ is a structure composed of two or more tissue types that work together to carry out a particular function.

a. Organs have definite anatomic boundaries and are distinguishable from other structures.

b. Organs within organs exist; the skin is the body’s largest organ, but contains thousands of smaller organs such as glands, hairs, nerves, etc.

4. A tissue is a mass of similar cells and cell products that forms a discrete region in an organ and carries out a specific function.

a. The body is composed of only four primary tissue classes: epithelial, connective, nervous, and muscular.

5. Cells are the smallest units of an organism that can carry out all the basic functions of life.

6. Organelles are microscopic structures within a cell that carry out individual functions.

a. Examples include mitochondria, centrosomes, and lysosomes.

7. Molecules are groups of two or more atoms bonded together.

8. Cells and their organelles contain highly complex macromolecules.

9. Atoms are the smallest particles of matter that have unique chemical identities.

10. Reductionism is the theory that a large, complex system can be understood by studying its simpler components.

a. Reductionism has been a highly productive approach but is not the last word in understanding human life.

11. Holism is the theory that whole organisms have “emergent properties” that cannot be predicted from the properties of their component parts.

a. Human beings are more than the sum of their parts.

b. To be most effective, health care providers must treat the whole person, not just a disease or an organ system.

B. Anatomical variation is normal, and reference books and materials usually provide only the most common form based on 70% of the population. (pp. 14–15) (Fig. 1.9)

1. Some people lack certain organs, such as certain muscles.

2. Some people have variations in structures, such as four or six lumbar vertebrae instead of five, or differences in number and morphology of kidneys.

Insight 1.2 Situs Inversus and Other Unusual Anatomy

VI. Human Function (pp. 15–19)

A. Life is characterized by several properties: organization, cellular composition, metabolism and excretion, responsiveness and movement, homeostasis, development, reproduction, and evolution. (p. 16)

1. Living things exhibit a higher level of organization than the nonliving world around them.

2. Living matter is composed of cells.

3. Living things take in molecules from the environment, change them, and excrete molecules they can no longer use.

a. Metabolism is the sum of all internal chemical changes and comprises anabolism, or synthesis reactions, and catabolism, or breakdown reactions.

b. Excretion is required to remove the waste molecules produced by metabolism.

4. Organisms can react to stimuli and are capable of movement.

a. The ability to sense and react to stimuli is called responsiveness, irritability, or excitability.

b. Most organisms can move from place to place, or are at least capable of moving materials internally within their bodies and cells.

5. Homeostasis is the ability to maintain stable internal conditions.

6. Development is any change in form or function over an organism’s lifetime.

a. Differentiation is the transformation of generalized cells into cells with specialized tasks.

b. Growth is an increase in size and occurs via chemical change.

7. All living things are capable of producing copies of themselves (offspring) and passing on their genes.

8. All living species exhibit genetic change from generation to generation and therefore evolve.

a. Mutations, changes in DNA structure, are inevitable.

b. Selection pressures mean that some individuals will be more successful than others.

c. Clinical and legal criteria for life are different from the biological criteria; a person may be declared legally dead if they show no brain function for 24 hours, no reflexes, no respiration, and no heartbeat other than provided by artificial means.

B. Physiological variables differ depending on sex, age, weight, diet, activity, environment, etc. (p. 17)

1. Values given in textbooks are for a healthy young adult unless otherwise stated.

2. The “reference man” is a healthy male 22 years old, weighing 70 kg (154 lb) living at an ambient temperature of 20°C, engaging in light physical activity and consuming 2800 kcals per day.

3. The “reference woman” is the same except for a weight of 58 kg (128 lb) and an intake of 2000 kcals per day.

C. Homeostasis is the ability to maintain stable internal conditions, and it is accomplished by the body’s negative feedback mechanisms. (pp. 17–18)

1. Physiology is largely a group of mechanisms for maintaining homeostasis.

a. Loss of homeostatic control can lead to illness or death.

b. Pathophysiology studies unstable conditions.

2. Internal conditions are not constant but fluctuate within a range.

a. The internal state of the body is best described as dynamic equilibrium.

b. The body’s characteristics, such as temperature, tend to vary around a certain set point or average value

3. Negative feedback. is a process in which the body senses a change and activates a process to reverse it. (Fig. 1.10)

a. A thermostat that controls room temperature is an example of a negative feedback system.

i. The thermostat is set to a temperature—the set point.