A&P Ch1 PDF

Chapter 1 Major Themes of Anatomy and Physiology ANATOMY & PHYSIOLOGY The Unity of Form and Function Ninth Edition Kenneth S. Saladin © 2022 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribu...

Chapter 1 Major Themes of Anatomy and Physiology ANATOMY & PHYSIOLOGY The Unity of Form and Function Ninth Edition Kenneth S. Saladin © 2022 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.  Introduction Anatomy and Physiology (A&P) are about human structure and function—the biology of the human body A & P form a foundation for advanced study in health care, exercise physiology, pathophysiology, and other related fields This chapter introduces: the history of A & P, human evolution, central concepts in physiology, ways to understand medical terminology © McGraw Hill 2  1.1 The Scope of Anatomy and Physiology Expected Learning Outcomes: Define anatomy and physiology and relate them to each other. Describe several ways of studying human anatomy. Define a few subdisciplines of human physiology. © McGraw Hill 3  Anatomy—The Study of Form 1 Examining structure of the human body Inspection Palpation Auscultation Percussion Cadaver dissection Cutting and separating human body tissues to reveal tissue relationships Comparative anatomy Study of multiple species to learn about form, function, and evolution © McGraw Hill 4  Anatomy—The Study of Form 2 Exploratory surgery Medical imaging Viewing the inside of the body without surgery Radiology—branch of medicine concerned with imaging Gross anatomy Study of structures that can be seen with the naked eye Histology (microscopic anatomy) Examination of tissues with microscope Histopathology Microscopic examination of tissues for signs of disease Cytology Study of structure and function of cells Ultrastructure View detail under electron microscope © McGraw Hill 5  Physiology—The Study of Function Subdisciplines Neurophysiology (physiology of nervous system) Endocrinology (physiology of hormones) Pathophysiology (mechanisms of disease) Comparative physiology Study of different species to learn about body functions Basis for much of our understanding of human physiology and the development of new drugs and medical procedures © McGraw Hill 6  1.2 The Origins of Biomedical Science Expected Learning Outcomes: Give examples of how modern biomedical science emerged from an era of superstition and authoritarianism. Describe the contributions of some key people who helped to bring about this transformation. © McGraw Hill 7  Greek and Roman Legacy 1 Hippocrates Greek physician; “Father of medicine” Established a code of ethics (Hippocratic Oath) Urged physicians to seek natural causes of disease rather than attributing them to acts of the gods and demons Aristotle Believed diseases had supernatural or physical causes Called supernatural causes of disease theologi Called natural causes for disease physiologi This gave rise to the terms physician and physiology Believed complex structures were built from simpler parts © McGraw Hill 8  Greek and Roman Legacy 2 Claudius Galen Physician to Roman gladiators Did animal dissections because use of cadavers was banned Saw science as a method of discovery Teachings (along with Aristotle) were adopted as dogma in Europe in Middle Ages © McGraw Hill 9  The Birth of Modern Medicine 1 Maimonides (Moses ben Maimon) Jewish physician who wrote 10 influential medical texts Was physician to Egyptian sultan, Saladin Avicenna (Ibn Sina) from Muslim world “The Galen of Islam” Combined both Galen and Aristotle’s findings with original discoveries Wrote The Canon of Medicine, used in medical schools for 500 years © McGraw Hill 10  The Birth of Modern Medicine 2 Andreas Vesalius Catholic Church relaxed restrictions on dissection of cadavers Performed his own dissections rather than having the barber– surgeons dissect Published first atlas of anatomy, De Humani Corporis Fabrica (On the Structure of the Human Body) in 1543 William Harvey Early physiologist—contributions represent the birth of experimental physiology Published book De Motu Cordis (On the Motion of the Heart) in 1628 Realized blood flows out from heart and back to it again Some credit also given to Michael Servetus for this © McGraw Hill 12  The Birth of Modern Medicine 3 Robert Hooke Made many improvements to compound microscope—two lenses: ocular lens (eyepiece) and objective lens (near specimen) Invented specimen stage, illuminator, coarse and fine focus controls His microscopes magnified only 30X First to see and name “cells” Published first comprehensive book of microscopy (Micrographia) in 1665 © McGraw Hill 13  The Birth of Modern Medicine 4 Antony van Leeuwenhoek Invented a simple (single-lens) microscope with great magnification to look at fabrics (200X) Published his observations of blood, lake water, sperm, bacteria from tooth scrapings, and many other things © McGraw Hill 15  The Birth of Modern Medicine 5 Matthias Schleiden and Theodor Schwann Examined wide variety of specimens Concluded that “all organisms were composed of cells” First tenet of cell theory Considered to be perhaps the most important breakthrough in biomedical history All functions of the body are interpreted as effects of cellular activity © McGraw Hill 16  1.3 Scientific Method 1 Expected Learning Outcomes: Describe the inductive and hypothetico–deductive methods of obtaining scientific knowledge. Describe some aspects of experimental design that help to ensure objective and reliable results. Explain what is meant by hypothesis, fact, law, and theory in science. © McGraw Hill 18  The Inductive Method Described by Francis Bacon Making numerous observations until one becomes confident in drawing generalizations and predictions Knowledge of anatomy obtained by this method Proof in science Reliable observations, repeatedly confirmed Not falsified by any credible observation In science, all truth is tentative “Proof beyond a reasonable doubt” © McGraw Hill 20  The Hypothetico–Deductive Method Most physiological knowledge gained by this method Investigator formulates a hypothesis—an educated speculation or possible answer to the question Good hypotheses are consistent with what is already known and are testable Falsifiability—if we claim something is scientifically true, we must be able to specify what evidence it would take to prove it wrong © McGraw Hill 21  Inductive vs. Deductive Inductive: You have a bag of coins; you pull five coins from the bag, and each coin is a penny. You then propose that all of the coins in the bag are pennies Does not guarantee conclusion will be true Deductive: All spiders have eight legs. A tarantula is a spider. Therefore, tarantulas have eight legs Dependent on the premises being true MODELING THE ANTIPODAL CONNECTIVITY STRUCTURE OF NEURAL COMMUNITIES (Thesis) - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/The-flow-diagrams-of-inductive-and-deductive-reasoning_fig2_293336132 [accessed 10 Oct, 2022] 22 © McGraw Hill  Experimental Design Sample size Number of subjects in a study Controls Control group resembles treatment group but does not receive treatment Psychosomatic effects Effects of subject’s state of mind on her or his physiology; tested by giving placebo to control group Experimenter bias Avoided with double-blind study Statistical testing Provides statement of probability that treatment was effective © McGraw Hill 23  Peer Review Critical evaluation by other experts in the field Done prior to funding or publication Done by using verification and repeatability of results Ensures honesty, objectivity, and quality in science © McGraw Hill 24  Facts, Laws, and Theories Scientific Fact Information that can be independently verified Law of Nature Generalization about the way matter and energy behave Results from inductive reasoning and repeated observations Written as verbal statement or mathematical formula Theory An explanatory statement or set of statements derived from facts, laws, and confirmed hypotheses Summarizes what we know; suggests directions for further study © McGraw Hill 25  1.4 Human Origins and Adaptations 1 Expected Learning Outcomes: Explain why evolution is relevant to understand human form and function. Define evolution and natural selection. Describe human characteristics that can be attributed to the tree-dwelling habits of earlier primates. Describe human characteristics that evolved later in connection with upright walking. © McGraw Hill 26  Human Origins and Adaptations 2 Charles Darwin On the Origin of Species by Means of Natural Selection (1859)—‟the book that shook the world” The Descent of Man (1871)—human evolution and relationship to other animals © McGraw Hill 27  Evolution, Selection, and Adaptation 1 Evolution Change in genetic composition of population of organisms; Example: development of bacterial resistance to antibiotics Natural selection How evolution works Selection pressures—forces that promote reproductive success of some individuals more than others; example: predators Adaptations—inherited features of anatomy and physiology that evolved in response to pressures and that enable organism to succeed; example: better camouflage © McGraw Hill 28  Evidence for Evolution: Exploration and Fossils Exploration- noticing variation in organisms when they are isolated Separate populations change over time different Accumulated differences can lead to speciation Fossils- record of past organisms May represent organisms that did not survive Could represent “missing links” © McGraw Hill By H. Raab (User: Vesta) - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=8066320 29  Evidence for Evolution: Homologous structures Homologous structures have the same origin (common ancestor) Bat wing and human arm Analogous structure: same structure/function but different origin Dolphin fin and shark vin © McGraw Hill By Encyclopaedia Britannica. Available: https://www.britannica.com/science/homology-evolution#/media/1/270557/45466 30  Evidence for Evolution: Vestigial, Embryological, Genetic Vestigial structures: structure no longer used as it was in the past Embryological: similarities in development between organisms Molecular markers- genetic similarities between related organisms © McGraw Hill By Pearson Education ©2018 31  Evolution, Selection, and Adaptation 2 Closest relative to human: chimpanzee Difference of only 1.6% in DNA structure Study of evolutionary relationships Help us chose animals for biomedical research (the animal model) Rats and mice used extensively due to cost and ethical issues involved with using chimpanzees © McGraw Hill 32  1.5 Human Structure Expected Learning Outcomes: List the levels of human structure from the most complex to the simplest. Discuss the value of both reductionistic and holistic viewpoints to understanding human form and function. Discuss the clinical significance of anatomical variation among humans. © McGraw Hill 37  The Hierarchy of Complexity 1 Organism composed of organ systems Organ systems composed of organs Organs composed of tissues Tissues composed of cells Cells composed of organelles Organelles composed of molecules Molecules composed of atoms © McGraw Hill 38  The Hierarchy of Complexity 2 Reductionism—large, complex systems can be understood by studying their simpler components Essential to scientific thinking Holism—“emergent properties” of the whole organism cannot be predicted from the properties of the separate parts Humans are more than the sum of their parts Treat the whole person, not just the disease or organ system © McGraw Hill 40  Anatomical Variation No two humans are exactly alike Anatomy books show most common organization of structures Some individuals lack certain muscles Some individuals have an atypical number of vertebrae Some individuals have an atypical number of certain organs (for example, kidneys) Some individuals show situs inversus—left–right reversal of organ placement © McGraw Hill 41  1.6 Human Function Expected Learning Outcomes: State the characteristics that distinguish living organisms from nonliving objects. Explain the importance of physiological variation among persons. Define homeostasis and explain why this concept is central to physiology. Define negative feedback, give an example of it, and explain its importance to homeostasis. Define positive feedback and give examples of its beneficial and harmful effects. Define gradient and describe the variety of gradients in human physiology, and identify some forms of matter and energy that flow down gradients. © McGraw Hill 43  Characteristics of Life 1 Organization—living things exhibit a higher level of organization than nonliving things Cellular composition—living matter is always compartmentalized into one or more cells Metabolism—internal chemical reactions Responsiveness—ability to sense and react to stimuli (irritability or excitability) Movement—of organism and/or of substances within the organism © McGraw Hill 44  Characteristics of Life 2 Homeostasis—maintaining relatively stable internal conditions Development—differentiation and growth Reproduction—producing copies of themselves; passing genes to offspring Evolution —changes in genes © McGraw Hill 45  Physiological Variation Sex, age, diet, weight, physical activity, genetics and environment Typical physiological values Reference man: 22 years old, 154 lb, light physical activity, consumes 2,800 kcal/day Reference woman: same as man except 128 lb and 2,000 kcal/day Failure to consider variation can lead to overmedication of elderly or medicating women on the basis of research done on men © McGraw Hill 46  Negative Feedback and Homeostasis 1 Homeostasis—the ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions Negative feedback allows for dynamic equilibrium within a limited range around a set point The body senses a change and “negates” or reverses it Loss of homeostatic control causes illness or death Because feedback mechanisms alter the original changes that triggered them, they are called feedback loops. © McGraw Hill 47  Negative Feedback and Homeostasis 2 Homeostasis in body temperature If too warm, vessels dilate in the skin and sweating begins (heat-losing mechanism) If too cold, vessels in the skin constrict and shivering begins (heat-gaining mechanism) © McGraw Hill 49  Negative Feedback and Homeostasis 3 Receptor—structure that senses change in the body (e.g., stretch receptors above heart that monitor blood pressure) Integrating (control) center—control center that processes the sensory information, “makes a decision,” and directs the response (e.g., cardiac center of the brain) Effector— cell or organ that carries out the final corrective action to restore homeostasis (e.g., the heart) © McGraw Hill 53  Positive Feedback and Rapid Change Self-amplifying cycle Leads to greater change in the same direction Feedback loop is repeated—change produces more change Normal way of producing rapid changes Examples include: childbirth, blood clotting, protein digestion, and generation of nerve signals Can sometimes be dangerous Example: vicious circle of runaway fever © McGraw Hill 54  Gradients and Flow Gradient—a difference in chemical concentration, charge, temperature, or pressure between two points Matter and energy tend to flow down gradients Example: blood flows from a place of higher pressure to a place of lower pressure Movement in the opposite direction is “up the gradient” and requires spending metabolic energy Chemicals flow down concentration gradients Charged particles flow down electrical gradients Heat flows down thermal gradients © McGraw Hill 56  1.7 The Language of Medicine Expected Learning Outcomes: Explain why modern anatomical terminology is so heavily based on Greek and Latin. Recognize eponyms when you see them. Describe the efforts to achieve an internationally uniform anatomical terminology. Break medical terms down into their basic word elements. State some reasons why the literal meaning of a word may not lend insight into its definition. Relate singular noun forms to their plural and adjectival forms. Discuss why precise spelling is important in anatomy and physiology. © McGraw Hill 59  The History of Anatomical Terminology About 90% of our current medical terms come from 1,200 Greek and Latin roots reflecting ancient past The Renaissance brought progress but confusion Same structures named differently in varied countries Some structures named after people (eponyms) 1895: Anatomists established worldwide naming conventions Rejected eponyms; used unique Latin names 1998: Terminologia Anatomica (TA) Provided Latin names and English equivalents Adopted by anatomists in over 50 countries © McGraw Hill 60  Analyzing Medical Terms Terminology based on word elements Lexicon of 400 word elements can be found on the inside back cover of textbook Scientific terms One root (stem) with core meaning Combining vowels join roots into a word Prefix and/or suffix may modify meaning of root word Acronyms—pronounceable words formed from first letter, or first few letters, of series of words Example: PET scan © McGraw Hill 61  Plurals, Adjectives, and Possessive Forms Plural forms vary Examples: cortex–cortices, corpus–corpora Adjective often follows noun it modifies Example: Biceps brachii Adjectival form of a term can appear different than noun form Example: brachium (n.): arm vs. brachii (adj.): of the arm © McGraw Hill 62  The Importance of Spelling Be precise in use and spelling of terms Many terms are spelled similarly but have very different meanings Health-care professions demand precision in order to maintain patient safety A small spelling mistake can have major health implications © McGraw Hill 64