Lecture 1 - Major Themes of Anatomy and Physiology PDF

Official Business MAJOR THEMES OF ANATOMY AND PHYSIOLOGY SYSTEMS PHYSIOLOGY 1 Official Business Agenda Define anatomy and physiology and relate them to each other. Describe several ways o...

Official Business MAJOR THEMES OF ANATOMY AND PHYSIOLOGY SYSTEMS PHYSIOLOGY 1 Official Business Agenda Define anatomy and physiology and relate them to each other. Describe several ways of studying human anatomy. Explain the importance of physiological variation among persons. Define homeostasis and explain why this concept is central to physiology. Explain why modern anatomical terminology is so heavily based on Greek and Latin. Break medical terms down into their basic word elements. Official Business Introduction Anatomy – study of structure Physiology – study of function Anatomy and physiology are complementary and never entirely separable Physiology provides meaning to anatomy Anatomy is what makes physiology possible Official Business Anatomy: The Study of Form Ways to examine structure of the human body: Inspection — look at appearance Palpation — feeling a structure with the hands Auscultation — listening to sounds produced by body Percussion — tap on the body, feel for resistance, and listen to emitted sound for abnormalities Dissection — cutting and separating human body tissues to reveal tissue relationships; use a cadaver, a dead human body Comparative anatomy — study (for example, dissection) of multiple species to learn about form, function, and evolution Exploratory surgery — opening the living body to see what is wrong; now replaced by medical imaging to view inside without surgery Radiology — branch of medicine specializing in imaging Official Business Anatomy: The Study of Form Subdisciplines of anatomy include: 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; fine detail (ultrastructure) may be resolved using an electron microscope Official Business Physiology: The Study of Function Physiology uses the methods of experimental science Subdisciplines of physiology include: 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 Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organism composed of organ systems Organ systems composed of organs Organs composed of tissues Tissues composed of cells Cells composed partly of organelles Organelles composed of molecules Molecules composed of atoms Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organism composed of organ systems Organ systems composed of organs Organs composed of tissues Tissues composed of cells Cells composed partly of organelles Organelles composed of molecules Molecules composed of atoms Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organism – a single, complete individual Organ systems – group of organs with a collective function Organs – two or more tissues working together Tissues – similar cells performing a specific function Cells – smallest unit of life Organelles – structure within a cell that carries out tasks Molecules – two or more atoms Atoms – smallest particle with unique identity Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organ systems – group of organs with a collective function Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organ systems – group of organs with a collective function Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organism – a single, complete individual Organ systems – group of organs with a collective function Organs – two or more tissues working together Tissues – similar cells performing a specific function Cells – smallest unit of life Organelles – structure within a cell that carries out tasks Molecules – two or more atoms Atoms – smallest particle with unique identity Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Tissues – similar cells performing a specific function Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Tissues – similar cells performing a specific function Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Tissues – similar cells performing a specific function Official Business Hierarchy of Complexity Human organization based on successive levels of hierarchy Organism – a single, complete individual Organ systems – group of organs with a collective function Organs – two or more tissues working together Tissues – similar cells performing a specific function Cells – smallest unit of life Organelles – structure within a cell that carries out tasks Molecules – two or more atoms Atoms – smallest particle with unique identity Official Business Hierarchy of Complexity Official Business Anatomical Variation No two humans are exactly alike; even identical twins have differences 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 Official Business Anatomical Variation: Example Official Business Anatomical Variation: Example Official Business Physiological Variation Physiology is even more variable than anatomy Variations in sex, age, diet, weight, physical activity, genetics and environment Typical physiological values Reference man: 22 years old, 154 lbs, light physical activity, consumes 2,800 kcal/day Reference woman: same as man except 128 lbs 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 Official Business How do we regulate physiology? Homeostasis – the ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions. Claude Bernard (1813 to 78) noted fairly constant internal conditions despite changing external conditions (for example, temperature) Walter Cannon (1871 to 1945) coined the term homeostasis 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 Official Business Negative Feedback Internal conditions fluctuate within a limited range Dynamic equilibrium around a set point Negative feedback—mechanism that keeps a variable close to set point; the body senses a change and reverses it Because feedback mechanisms alter the original changes that triggered them, they are called feedback loops Example: homeostasis in body temperature If too warm, skin blood vessels dilate (vasodilation) and sweating begins (heat-losing mechanism) If too cold, skin blood vessels constrict (vasoconstriction) and shivering begins (heat-gaining mechanism) Official Business Negative Feedback Loop Official Business Negative Feedback Loop Official Business Negative Feedback Loop Official Business Positive Feedback Positive feedback is a self-amplifying cycle Leads to greater change in the same direction, as opposed to the corrective action of negative feedback Normal way of producing rapid changes Examples: childbirth, blood clotting, protein digestion, and generation of nerve signals Can sometimes be dangerous Example: vicious circle of runaway fever Official Business Positive Feedback Loop  Biomedical Imaging Official Business Official Business The Language of Medicine SYSTEMS PHYSIOLOGY 1 Official Business 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) In 1895, anatomists established worldwide naming conventions Rejected eponyms; used unique Latin names Terminologia Anatomica (TA) provides standard international anatomical terms Provided Latin names and English equivalents In 1998, approved by anatomists in over 50 countries Official Business Anatomy of Anatomical Terminology Anatomical terminology based on word elements such as roots, prefixes, suffixes. 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: P E T scan Official Business Official Business Anatomy of Anatomical Terminology Hyponatremia … Hypo – natron – emia (below normal) – (sodium) – (blood condition) Therefore, it is the deficiency of sodium in the blood. Official Business Anatomy of Anatomical Terminology Cardiology … Cardi – o – log – y (heart, from kardia, Gr.) – (study of, from logos and process, from y Gr.) Therefore, it is the study of the heart. Official Business Anatomy of Anatomical Terminology Gastroenterology … Gastro – entero – log – y (stomach) – (small intestines) – (study of) Therefore, it is the branch of medicine dealing with the stomach and the small intestines. Official Business Anatomy of Anatomical Terminology Anatomical terminology based on word elements such as roots, prefixes, suffixes. 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: P E T scan Official Business Official Business Official Business Official Business Official Business Anatomical Position Shown on the right is the standard anatomical position. This is used as the reference when describing the position of organs. Official Business Anatomical Position Sagittal – left and right (median plane) Frontal (coronal) – perpendicular; anterior and posterior Transverse (horizontal) – perpendicular; superior and inferior Official Business Anatomical Direction Official Business Anatomical Direction Official Business Anatomical Direction Proximal = toward the trunk; near the origin Distal = away from the trunk; far from the origin Official Business Anatomical Direction The ankle is _________ to the foot. The knee is _________ to the ankle. The hip is _________ to the knee. The knee is _________ to the hip. The ankle is _________ to the knee. The foot is _________ to the ankle. Official Business Anatomical Cavities Official Business Anatomical Cavities Official Business