WELCOME TO A&P I Vladimir Jurukovski PhD Associate Professor Suffolk County Community College Smithtown Science Building T-218 (631) 451-4362 [email protected] http://www2.sunysuffolk.edu/jurukov.
Download ReportTranscript WELCOME TO A&P I Vladimir Jurukovski PhD Associate Professor Suffolk County Community College Smithtown Science Building T-218 (631) 451-4362 [email protected] http://www2.sunysuffolk.edu/jurukov.
WELCOME TO A&P I Vladimir Jurukovski PhD Associate Professor Suffolk County Community College Smithtown Science Building T-218 (631) 451-4362 [email protected] http://www2.sunysuffolk.edu/jurukov WHAT IF…..? INTRODUCTION Anatomy and physiology (A&P) is about human structure and function—the biology of the human body We want to know how our body works! A&P is a foundation for advanced study in health care, exercise physiology, pathophysiology, and other healthcare-related fields Considers the historical development and a central concept of physiology—homeostasis 1-4 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. 1-5 ANATOMY—THE STUDY OF FORM Examining structure of the human body Cadaver dissection Figure 1.1 Inspection Palpation Auscultation Percussion Cutting and separation of tissues to reveal their relationships Comparative anatomy Study of more than one species in order to examine structural similarities and differences, and analyze evolutionary trends 1-6 Cadaver Dissection ANATOMY—THE STUDY OF FORM Exploratory surgery Medical imaging Examination of cells with microscope Ultrastructure Study of structure and function of cells Histology (microscopic anatomy) Study of structures that can be seen with the naked eye Cytology Viewing the inside of the body without surgery Radiology—branch of medicine concerned with imaging Gross anatomy Open body and take a look inside View molecular detail under electron microscope Histopathology Microscopic examination of tissues for signs of disease 1-8 Exploratory Surgery Cytology Histology Medical Imaging Gross Anatomy PHYSIOLOGY—THE STUDY OF FUNCTION Subdisciplines Neurophysiology (physiology of nervous system) Endocrinology (physiology of hormones) Pathophysiology (mechanisms of disease) Comparative physiology Limitations on human experimentation Study of different species to learn about bodily function Animal surgery Animal drug tests Basis for the development of new drugs and medical procedures 1-10 LIVING IN A REVOLUTION Modern biomedical science Technological enhancements Advances in medical imaging have enhanced our diagnostic ability and life-support strategies Genetic Revolution Human genome is finished Gene therapy is being used to treat disease Early pioneers were important Established scientific way of thinking Replaced superstition with natural laws 1-11 HUMAN STRUCTURE Expected Learning Outcomes List the levels of human structure from the most complex to the simplest. Discuss the clinical significance of anatomical variation among humans. 1-12 1-13 HIERARCHY OF COMPLEXITY Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Organism is composed of organ systems Organism Organ Systems composed of organs Organs composed of tissues Tissues composed of cells Cells composed of organelles Organelles composed of molecules Organ system Tissue Organ Cell Macromolecule Organelle Molecules composed of atoms Atom Molecule 1-14 HIERARCHY OF COMPLEXITY Organism – a single, complete individual Organ System – human body made of 11 organ systems Organ – structure composed of two or more tissue types that work together to carry out a particular function Tissue – a mass of similar cells and cell products that form discrete region of an organ and performs a specific function Cells – the smallest units of an organism that carry out all the basic functions of life Cytology – the study of cells and organelles Organelles – microscopic structures in a cell that carry out its individual functions Molecules – make up organelles and other cellular components macromolecules – proteins, carbohydrates, fats, DNA Atoms – the smallest particles with unique chemical identities CHARACTERISTICS OF LIFE Organization Cellular composition Metabolism anabolism, catabolism and excretion Responsiveness and movement Stimuli Homeostasis Development differentiation and growth Reproduction Evolution mutations 1-15 ANATOMICAL VARIATION No two humans are exactly alike 70% most common structure 30% anatomically variant Variable number of organs Missing muscles, extra vertebrae, renal arteries Variation in organ locations (situs solitus, situs inversus, dextrocardia, situs perversus) Normal Pelvic kidney Normal Horseshoe kidney 1-16 Variations in branches of the aorta PHYSIOLOGICAL VARIATION Sex, age, diet, weight, physical activity Typical physiological 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 1-17 HOMEOSTASIS Homeostasis – the body’s ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions Claude Bernard (1813-78) constant internal conditions regardless of external conditions internal body temperature ranges from 97 to 99 degrees despite variations in external temperature Walter Cannon (1871-1945) coined the term ‘Homeostasis’ state of the body fluctuates (dynamic equilibrium) within limited range around a set point Negative feedback keeps variable close to the set point Loss of homeostatic control causes illness or death 1-18 NEGATIVE FEEDBACK LOOP Body senses a change and activates mechanisms to reverse it—dynamic equilibrium Because feedback mechanisms alter the original changes that triggered them (temperature, for example), they are called feedback loops Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Room temperature fallsto66°F(19°C) 1 C10° 15°20°25° 6 Room cools down F50° 60°70°80° 2 C10° 15°20°25° Thermost atactivates furnace F50° 60°70°80° Figure 1.9a 5 Thermostat shuts off furnace 4 Room temperature rises to 70°F (21°C) 3 Heat output (a) 1-19 NEGATIVE FEEDBACK Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Room temperature (oF) 75 (b) Furnace turned off at 70 oF 70 Set point 68 oF 65 Furnace turned on at 66 oF 60 Figure 1.9b Time Example: Room temperature does not stay at set point of 68°F—it only averages 68°F 1-20 NEGATIVE FEEDBACK Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Core body temperature Sweating 37.5 oC (99.5 oF) Vasodilation 37.0 oC (98.6 oF) 36.5 oC (97.7 oF) Set point Vasoconstriction Figure 1.10 Time Shivering Example: Brain senses change in blood temperature If too warm, vessels dilate (vasodilation) in the skin and sweating begins (heat-losing mechanism) If too cold, vessels in the skin constrict (vasoconstriction) and shivering begins (heat-gaining mechanism) 1-21 HOMEOSTATIS AND NEGATIVE FEEDBACK Sitting up in bed causes a drop in blood pressure in the head and upper torso region (local imbalance in homeostasis); detected by baroreceptors Baroreceptors (sensory nerve endings) in the arteries near the heart alert the cardiac center in the brainstem. They transmit to the cardiac center Cardiac center sends nerve signals that increase the heart rate and return the blood pressure to normal; regulates heart rate Failure of this to feedback loop may produce dizziness in the elderly 1-22 POSTURAL CHANGE IN BLOOD PRESSURE Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Person rises from bed Blood pressure rises to normal; homeostasis is restored Cardiac center accelerates heartbeat Blood drains from upper body, creating homeostatic imbalance Baroreceptors above heart respond to drop in blood pressure Figure 1.11 Baroreceptors send signals to cardiac center of brainstem HOMEOSTASIS AND NEGATIVE FEEDBACK Receptor—senses change in the body (e.g., stretch receptors 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—carries out the final corrective action to restore homeostasis (e.g., cell or organ) 1-24 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 Occurs with childbirth, blood clotting, protein digestion, fever, and generation of nerve signals 1-25 POSITIVE FEEDBACK AND RAPID CHANGE During birth, the head of the fetus pushes against the cervix and stimulates its nerve endings Hormone oxytocin is secreted from the pituitary gland Oxytocin travels through the bloodstream to the uterus stimulating it to contract This action pushes the fetus downward toward cervix, thus stimulating the cervix more, causing the positive feedback loop to be repeated 1-26 POSITIVE FEEDBACK LOOPS Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 Brain stimulates pituitary gland to secrete oxytocin 4 Oxytocin stimulates uterine contractions and pushes fetus toward cervix 2 Nerve impulses from cervix transmitted to brain 1 Head of fetus pushes against cervix 1-27 POSITIVE FEEDBACK AND RAPID CHANGE Fever > 104°F Metabolic rate increases Body produces heat even faster Body temperature continues to rise Further increasing metabolic rate Cycle continues to reinforce itself Becomes fatal at 113°F 1-28 REVIEW OF MAJOR THEMES Cell Theory Homeostasis The human body is a product of evolution Hierarchy of Structure The purpose of most normal physiology is to maintain stable conditions within the body Evolution All structure and function result from the activity of cells Human structure can be viewed as a series of levels of complexity Unity of Form and Function Form and function complement each other; physiology cannot be divorced from anatomy 1-29 MEDICAL IMAGING Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Radiography (X-rays) (a) X-ray (radiograph) William Roentgen’s discovery in 1885 Penetrate tissues to darken photographic film beneath the body Dense tissue appears white Over half of all medical imaging Until 1960s, it was the only method widely available © U.H.B. Trust/Tony Stone Images/Getty Imagese Figure 1.13a 1-30 MEDICAL IMAGING Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Radiopaque substances Injected or swallowed Fills hollow structures Blood vessels Intestinal tract Figure 1.13b (b Cerebral angiogram Custom Medical Stock Photos, Inc. 1-31 MEDICAL IMAGING Computed tomography (CT scan) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Formerly called a CAT scan Low-intensity X-rays and computer analysis Slice-type image Increased sharpness of image Figure 1.13c (c) Computed tomographic (CT) scan © CNR/Phototake 1-32 MEDICAL IMAGING—NUCLEAR MEDICINE Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Positron emission tomography (PET) scan Assesses metabolic state of tissue Distinguished tissues most active at a given moment Mechanics—inject radioactively labeled glucose Positrons and electrons collide Gamma rays given off Detected by sensor Analyzed by computer Image color shows tissues using the most glucose at that moment Damaged tissues appear dark (d) Positron emission tomographic (PET) scan Tony Stone Images/Getty Images Figure 1.13d 1-33 MEDICAL IMAGING Magnetic resonance imaging (MRI) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slice-type image Superior quality to CT scan Best for soft tissue Mechanics Alignment and realignment of hydrogen atoms with magnetic field and radio waves Varying levels of energy given off used by computer to produce an image (e) Magnetic resonance image (MRI) © Monte S. Buchsbaum, Mt. Sinai School of Medicine, New York, NY Figure 1.13e 1-34 MEDICAL IMAGING Sonography Second oldest and second most widely used Mechanics High-frequency sound waves echo back from internal organs Avoids harmful X-rays Obstetrics Image not very sharp Figure 1.14 1-35