Major Themes of Anatomy and Physiology Unit 1 – Chapter 1 Major Themes of Anatomy and Physiology

Major Themes of Anatomy and Physiology Form and Function Homeostasis

Anatomy - The Study of Form Observation of surface structure Cadaver dissection cutting and separation of organs to study their relationships Comparative anatomy study of more than one species to analyze evolutionary trends

Anatomy - The Study of Form 2 Physical examination palpation, auscultation, percussion Gross anatomy visible with naked eye Histology examination of cells with microscope

Early Medical Illustrations

Physiology - The Study of Function Study of bodily functions using methods of experimental science Comparative physiology study of different species Basis for the development of new drugs and medical procedures

Hierarchy of complexity organism is composed of organ systems organ systems composed of organs organs composed of tissues tissues composed of cells

Hierarchy of Complexity 2 Cells contain organelles Organelles composed of molecules Molecules composed of atoms

Anatomical Variation No 2 humans are exactly alike variable number of organs variation in organ locations (situs inversus, dextrocardia, situs perversus)

Characteristics of Life Organization Cellular composition Excretion Metabolism and excretion Responsiveness and movement Homeostasis Development Reproduction Evolution

Physiological Variation Sex, age, diet, weight, physical activity Typical values reference man 22 years old, 154 lbs, light physical activity consumes 2800 kcal/day reference woman same as man except 128 lbs and 2000 kcal/day

Homeostasis Claude Bernard (1813-78) Homeostasis stable internal conditions regardless of external conditions Homeostasis Walter Cannon (1871-1945) coined the term fluctuates within limited range around a set point Loss causes illness or death

Negative Feedback Loop Body senses a change and activates mechanisms to reverse it

Negative Feedback, Set Point Room temperature does not stay at set point of 68 degrees -- it only averages 68 degrees

Human Thermoregulation Brain senses change in blood temperature if overheating, vessels dilate in the skin and sweating begins if too cold, vasoconstriction in the skin and shivering begins

Control of Blood Pressure Circulatory stretch receptors detect a rise in BP Cardiac center in brainstem sends out nerve signals Heart slowed and BP lowered

Structure of Feedback Loop Receptor = senses change Integrator = control center that responds Effector = structures that restore homeostasis

Positive Feedback Loops Self-amplifying change leads to change in the same direction Normal way of producing rapid changes occurs with childbirth, blood clotting, protein digestion, and generation of nerve signals

Life-Threatening Fever Temperature > 108 degrees F increases metabolic rate body produces heat even faster Cycle continues to reinforce itself Becomes fatal at 113 degrees F

Anatomical Terminology Medical terms from Greek and Latin roots Naming confusion during the Renaissance same structures with different names structures named after people (eponyms) Search for uniform international terminology 1895 Nomina Anatomica (NA) rejected all eponyms each structure = unique Latin name Terminologia Anatomica was codified in 1998

Analyzing Medical Terms Terminology based on word elements lexicon (Appendix C) Scientific terms one root (stem) with core meaning combining vowels join roots prefix modifies core meaning suffix modifies core meaning Acronyms first few letters of series of words

Useful Tables in Textbook

Review of Major Themes Cell theory Homeostasis Evolution activity of cells determine structure and function Homeostasis maintaining stable internal conditions Evolution our body evolved by natural selection Hierarchy of structure levels of complexity Unity of form and function physiology is inseparable from anatomy

Medical Imaging Radiography (x rays) Radiopaque substances William Roentgen - 1885 penetrate soft tissues and darken photographic film dense tissue remains white Radiopaque substances injected or swallowed hollow structures blood vessels intestinal tract

Medical Imaging Computed Tomography (CT scan) low-intensity X rays and computer analysis slice type image increased sharpness Magnetic Resonance Imaging (MRI) best for soft tissue Mechanics magnetic field aligns atoms radio waves realign the atoms radio turned off atoms realign to the magnetic field energy given off depending on tissue type

Medical Imaging Positron Emission Tomography (PET scan) assesses metabolic state mechanics inject labeled glucose positrons and electrons collide gamma rays given off analyzed by computer image glucose usage

Medical Imaging Sonography mechanics avoids harmful x rays obstetrics high-frequency sound waves echo back from internal organs avoids harmful x rays obstetrics 2nd most commonly used technique