08 26 2014 Chapter 1 Major Themes of Anatomy and Physiology Anatomy The study of human structure or form What things look like Physiology Study of function Cannot be determined just by looking Relies heavily on other disciplines i e biochemistry biology chemistry genetics Anatomy The Study of Form Examining structure of the human body o Inspection Method of examination by simply looking at the appearance of the body Exploratory Surgery Method previously used to open body in order to figure out what was wrong inside Radiology Uses imaging techniques in order to look inside a body replaced exploratory surgery Cytology The study of the structure and function of cells and organelles Fluid from body Histology Microscopic anatomy Observing individual cells via thinly sliced tissue specimen under microscope Sample of tissue from body Ultrastructure o Palpation Feeling a structure with the hands i e taking a pulse feeling a swollen lymph node o Auscultation Listening to natural sounds made by body i e breathing in the lungs heartbeat o Percussion Tapping on the body to feel for abnormal resistance and listen to the emitted sounds for signs of abnormality Cadaver Dissection Using human bodies to study structures etc o Anatomy dissection cutting apart o Cadaver dead human body o Dissection Carefully cutting and separating tissues to reveal relationships Comparative Anatomy Using animals with similar structures to humans in place of cadavers o Ex Sheep brain dissection in place of human brain dissection Gross Anatomy Able to be seen with the naked eye Physiology The Study of Function Subdisciplines o Neurophysiology Functions of the nervous system o Endocrinology Functions of the hormones etc o Pathophysiology Mechanisms of disease Comparative Physiology Test on other species because of limitations of human experimentation Scientific Method Scientific Method 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 o DRIVEN BY OBSERVATIONS o System that gives a set of standards for collecting and reporting data o Observation Inductive reasoning questions Formation of a hypothesis must be testable Carry out experiments should always be reproducible Make predictions deductions to test and eliminate earlier predictions Francis Bacon England Inductive Method o Inductive Method Making observations without change in variables until one feels confidence in drawing generalizations and predictions from them Used more often for anatomy Rene Descartes France Hypothetico Deductive Method o Hypothetico Deductive Method Form hypotheses and ask questions Used more often for physiology o Characteristics of a good hypothesis Consistent with what is already known Testable and possibly falsifiable with evidence 08 26 2014 Homeostasis Maintaining and internal stable condition regardless of what s going on externally Claude Bernard 1813 1878 o First person to observe and acknowledge homeostasis Walter Cannon 1871 1945 o Homeostasis as a name for what Bernard discovered Negative Feedback o Dynamic Equilibrium within a limited range around a set point There is a range that things can change within but that range is set ex thermostat between 68 72 degrees operates to maintain temperature in that specific range o Majority of the mechanisms used to maintain homeostasis are negative feedback Range of mechanism determines when the stimulus is dealt with and when it is left alone o Response either overrides or eliminates the initial stimulus Ex Thermostat The temperature is the stimulus that needs to be overridden Once the heat comes on the heat overrides the stimulus of the dropping temperature o Receptor Receives the stimulus o Integrating control Center Processes the signal and sends instructions o Effector Carries out instructions o As it relates to the body there are mechanisms to detect changes in pH temperature blood pressure etc Integrating Center of body BRAIN Effectors may be anything from blood vessels heart blood pressure sweat glands skin blood vessels temperature Dependent on what the stimulus is o Ex Thermoreceptors sense changes in blood temperature Vasodilation Vasoconstriction Receptors Temperature sensors in skin and hypothalamus o Ex Orthostatic Hypotension Becoming dizzy upon going from sitting to standing Anytime you stand up blood pressure drops For older people baroreceptors do not kick in to normalize blood pressure as quickly Positive Feedback and Rapid Change o Self Amplifying Cycle Leads to greater change in the same direction Rather than stopping the stimulus it acts to increase the stimulus Normal way of producing rapid changes i e blood clotting fever childbirth blood clotting protein digestion fever and generation of nerve signals o Ex Childbirth The initial stimulus for the release of oxytocin from the hypothalamus is the pressure of the fetus head pressing against the cervix which causes cervical contraction and more pressure from the head against the cervix Once the baby is born the pressure is gone and oxytocin ceases release from the hypothalamus which causes the cervical contractions to stop o Ex Fever 104 degrees F The hypothalamus has a dynamic range of 98 4 98 8 degrees F Fever begins when a microorganism resets the standard temperature and the body must adjust to get warmer Fever causes a cold feeling because microorganisms can reset the dynamic range to something much higher making normal feel cold Once you hit the desired temperature of the reset temperature the body decides that it isn t warm enough and resets it to make it higher causing the fever to get worse Temperature will continue to increase until fever is treated i e ice acetaminophen Gradients and Flow Matter and energy tend to flow down gradient a difference in chemical concentration charge temperature or pressure between two points o Default to flow from high low o Some mechanisms will cause flow against the gradient low high The History of Anatomical Terminology Naming confusion during Renaissance o Same structures different names in different countries Standard international anatomical terminology Terminologia Anatomica TA About 90 of medical terms have Greek or Latin root Analyzing Medical Terms Terminology based on word elements Scientific terms consist of root prefix and suffix Acronyms formed from first letter or first few letters of series of words o Ex Calmodulin Calcium