GEN%20PHYSIOLOGY%20LECTURE.docx

**PHYSIOLOGY LECTURE** **ORGANIZATION OF LIFE** **Organism** is 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*...

**PHYSIOLOGY LECTURE** **ORGANIZATION OF LIFE** **Organism** is 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** ** 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. - **Anatomy**- study of form - inspection\ -- palpation\ -- auscultation\ -- percussion - **Cadaver Dissection**- 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. - **Exploratory Surgery**\ -- open body and take a look inside\ 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\ **Cytology** -- study of structure and function of cells. **Histology (microscopic anatomy**)\ -- examination of cells with microscope\ **Ultrastructure** -- the molecular detail seen in electron microscope\ **Histopathology** -- microscopic examination of tissues for signs of disease. - **Physiology**- 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. - **Evolution**-- change in genetic composition of population of organism. - **Natural Selection** -- some individuals within a species have hereditary advantage over their competitors\ better camouflage\ disease resistance\ ability to attract mates - **Cell Theory** -- All structure and function result from the activity of cells - **Physicians in Mesopotamia and Egypt\ -- 3000 years ago used herbal drugs, salts and physical therapy\ ** - **Christian culture of Europe in Middle Ages**\ -- science severely repressed\ -- taught medicine primarily as dogmatic commentary on Galen and Aristotle\ -- crude medical illustrations\ ** In Jewish and Muslim cultures free inquiry was less inhibited**\ Jewish physician **Maimonides (Moses ben Maimon)\ **-- wrote 10 influential medical texts\ -- was physician to Egyptian sultan, Saladin\ **Avicenna (Ibn Sina) from Muslim world\ **-- "the Galen of Islam"\ -- combined Galen and Aristotle findings with original discoveries\ -- wrote The Canon of Medicine, used in medical schools for 500 years. - **Selection Pressures** -- natural forces that promote the reproductive success of some individuals more than others. - **Adaptations** -- features of an organism's anatomy, physiology, or behavior that have evolved in response to these selection pressures and enable the organism to cope with the challenges of its environment.\ -- **Model** -- animal species selected for research on a particular problem. - **Closest relative - chimpanzee**\ -- difference of only 1.6% in DNA structure\ -- chimpanzees and gorillas differ by 2.3% - **Bipedalism** - standing and walking on 2 legs\ -- helps spot predators, carry food or infants\ **Adaptations for bipedalism**\ -- skeletal and muscular modifications\ -- increased brain volume\ -- family life and social changes - **Australopithecu**s -- oldest bipedal primate\ **Homo genus** (appeared 2.5 million years ago)\ taller, larger brain volume, probable speech, tool- making\ **Homo erectus (appeared 1.8 million years ago)\ **-- migrated from Africa to parts Asia\ Other Homo species discovered recently still matter of considerable debate\ **Homo sapiens originated in Africa 200,000 years ago\ **-- sole surviving hominid species\ **Evolutionary (Darwinian)** medicine traces some of our diseases and imperfections to our past. - **Reductionism** -- theory that a large, complex system such as the human body can be understood by studying its simpler components\ -- **first espoused by Aristotle**\ -- highly productive approach\ -- essential to scientific thinking\ **Holism** -- there are 'emergent properties' of the whole organism that cannot be predicted from the properties of the separate parts\ -- humans are more than the sum of their parts\ -- complementary theory to reductionism. - **Vestigial Organs** -- remnants of organs that apparently were better developed and more functional in the ancestors of a species, and now serve little or no purpose.\ -- piloerector muscle\ -- auricularis muscles - **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**) - **Primates** -- order of mammals to which humans, monkeys, and apes belong\ **Earliest Primates**\ -- squirrel-sized, arboreal, insect-eating African mammals\ -- moved to trees due to safety, food supply and lack of competition\ **Adaptations for arboreal (treetop) life style\ **-- mobile shoulders\ -- opposable thumbs made hands prehensile to grasp branches and encircle them with the thumb and finger\ -- forward-facing eyes (stereoscopic vision)\ depth perception for leaping and catching prey\ -- color vision\ distinguish ripe fruit and young, less toxic foliage\ -- larger brains and good memory\ remember food sources and improved social organization - **Homeostasis** -- the body's ability to detect change, activate mechanisms\ that oppose it, and thereby maintain relatively stable internal conditions. - **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. - **Brain senses change in blood temperature**\ -- if to warm, vessels dilate **(vasodilation)** in the skin and sweating\ begins (**heat losing mechanisms)**\ -- if too cold, vessels in the skin constrict **(vasoconstriction)** and shivering begins **(heat gaining mechanism)** - **Baroreceptors** in the arteries near the heart alert the cardiac center in the brainstem.\ **Cardiac center** sends nerve signals that increase the heart rate and return the blood pressure to normal. - **Receptor** - senses change in the body\ **Integrating (Control) Center** - control center that processes the sensory information, 'makes a decision', and directs the response\ **Effector** -- carries out the final corrective action to restore homeostasis. - Failure of this to feedback loop may produce dizziness in the elderly. - **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. - **Radiography (x rays)\ -- William Roentgen - 1885**\ -- penetrate tissues to darken photographic film beneath the body.\ -- dense tissue appears white\ -- over half of all medical\ imaging.\ -- until 1960's, it was the only\ method widely available.\ **Radiopaque substances**\ -- injected or swallowed\ -- fills hollow structures\ blood vessels\ intestinal tract  - **Computed Tomography\ (CT scan**)\ -- formerly called a CAT\ scan\ -- low-intensity X rays and\ computer analysis\ slice type image\ increased sharpness\ of image - **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 which tissues\ were using the most glucose at that moment\ -- damaged tissues appear dark - **Magnetic Resonance Imaging\ (MRI)**\ -- slice type image\ -- superior quality to CT scan\ -- best for soft tissue\ -- mechanics\ alignment & realignment of hydrogen atoms with magnetic field & radio waves.  - **Sonography**\ -- second oldest & second most widely used mechanics\ high-frequency sound waves echo back from internal organs\ -- avoids harmful x rays\ obstetrics\ image not very sharp **[BODY SYSTEMS]** - **Gross Anatomy:**\ Large, easily observable structures.\ (Ex: Heart, bones) - **Microscopic Anatomy**:\ Structures too small to observe with\ the naked eye.\ **Cytology** -- the study of cells\ **Histology** -- the study of tissues - **Cardiac Physiology:** study of the function of the heart. - Cells are made of organic molecules - **Skeletal System**- Serves as a framework of support - Protects internal organs - **Muscular System**- Skeletal muscles make up the muscular system.\ Contract/shorten for movement, heat production - **Nervous System**\ The body's fast-acting control system\ Consists of the brain, spinal cord, nerves, and sensory\ receptors. - **Endocrine System**: Endocrine Glands\ Regulates gradual changes within the body, with chemical controllers called hormones.\ Includes: Pituitary Gland, Thyroid, Parathyroids, Adrenals,Thymus, Pancreas, Pineal, Ovaries,. - **Cardiovascular System: Heart, Blood Vessels\ ** Delivery & transport of gases, nutrients and wastes - **Respiratory System: Lungs**\ Gas exchange (carbon dioxide ◊\ oxygen)\ Consists of nasal passages, pharynx, larynx, trachea, bronchi, and lungs. - **Digestive System**\ **Alimentary Canal**: A tube\ running through the body\ from mouth to anus. - Breakdown of food and absorption of nutrients - Include mouth, oral cavity, esophagus, stomach, small/large intestines, and rectum.\ **Urinary System**- Removes the nitrogen- containing wastes from\ the blood and flushes them from the body in urine.\ Includes kidneys, ureters, bladder, and urethra - **Lymphatic/Immune System**- Defends body against pathogens, infection and disease\ **Reproductive System**- Main function is producing offspring\ Produces gametes (egg and sperm)\ Male's R.S includes: sperm, testes, scrotum, penis, duct systems.\ Female's R.S includes: Ovaries, eggs, uterine tubes, vagina, and uterus **KEY FIGURES** +-----------------------------------+-----------------------------------+ | **HIPPOCRATES** | -- "**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** | **one of the first philosophers | | | to write about anatomy and | | | physiology**\ | | | -- believed that diseases had | | | either supernatural causes or | | | physical causes | | | | | | called supernatural causes of | | | disease **theology** | | | | | | called natural causes for | | | disease **physiologi\ | | | ** this gave rise to the terms: | | | physician and physiology\ | | | -- *believed that complex | | | structures are built from simpler | | | parts*. | +-----------------------------------+-----------------------------------+ | **CLAUDIUS GALEN** | -- physician to the Roman | | | gladiators\ | | | -- did animal dissections since | | | use of cadavers banned in his | | | time\ | | | -- saw science as a method of | | | discovery not just body of facts | | | taken on faith.\ | | | -- wrote book advising followers | | | to trust their own observation | | | more than the teaching of dogma | | | of the "ancient masters" | +-----------------------------------+-----------------------------------+ | **ANDREAS VESALIUS** | taught anatomy in Italy\ | | | -- Catholic Church relaxed | | | restrictions on dissection of | | | cadavers and permitting | | | autopsies.\ | | | -- barbering and surgery were | | | considered 'kindred arts of the | | | knife'.\ | | | -- performed his own dissections | | | rather than the barber-surgeons. | +-----------------------------------+-----------------------------------+ | **WILLIAM HARVEY** | early | | | physiologist\...contributions | | | represent the birth of | | | experimental physiology\ | | | -- remembered for early studies | | | on blood circulation\ | | | -- realized blood flows out from | | | heart and back to it again\ | | | -- published book De Motu Cordis | | | (On the Motion of the Heart) in | | | 1628 | +-----------------------------------+-----------------------------------+ | **MICHAEL SERVETUS** | along with Harvey, were the first | | | Western scientists to realize | | | that **blood must circulate | | | continuously around the body**, | | | from the heart to other organs, | | | and back to the heart again. | +-----------------------------------+-----------------------------------+ | **ROBERT HOOKE** | made many **improvements to the | | | compound microscope -2 | | | 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 named | | | 'cells'**\ | | | -- published first comprehensive | | | book of microscopy (Micrographia) | | | in 1665. | +-----------------------------------+-----------------------------------+ | **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. | +-----------------------------------+-----------------------------------+ | **MATTHIAS SCHLEIDEN AND THEODOR | with improved microscopes, | | SCHWANN** | examination of a wide variety of | | | specimens followed\ | | | **-- concluded that "all | | | organisms were composed of | | | cells"\ | | | -- first tenet of Cell Theory**\ | | | considered as the most | | | important breakthrough in | | | biomedical history\ | | | all functions of the body are | | | interpreted as effects of | | | cellular activity. | +-----------------------------------+-----------------------------------+ | **CLAUDE BERNARD** | constant internal conditions | | | regardless of external | | | conditions\ | | | internal body temperature | | | ranges from 97 to 99 degrees\ | | | Fahrenheit or 36-37 degrees | | | Celsius despite variations in | | | external\ | | | temperature | +-----------------------------------+-----------------------------------+ | **CARL ZEISS & ERNST ABBE** | -- greatly improved compound | | | microscopes\ | | | -- added condenser and superior | | | optics\ | | | - eliminated blurry edges | | | (spherical aberration) and | | | rainbow-like distortions | | | (chromatic aberration) | +-----------------------------------+-----------------------------------+ | **RENE DESCARTES** | philosophers who invented new | | | habits of scientific thought.\ | | | -- sought systematic way of | | | seeking similarities, | | | differences,and trends in nature | | | and drawing useful | | | generalizations from observable | | | facts. | +-----------------------------------+-----------------------------------+ | **FRANCIS BACON AND RENE | -- philosophers who invented new | | DESCARTES** | habits of scientific thought\ | | | -- sought systematic way of | | | seeking similarities, | | | differences, and trends in nature | | | and drawing useful | | | generalizations from observable | | | fact. | +-----------------------------------+-----------------------------------+ | **CHARLES DARWIN** | On the Origin of Species by Means | | | of Natural Selection\ | | | (1859) -- 'book that shook the | | | world'\ | | | -- The Descent of Man (1871) -- | | | human evolution\ | | | **Theory of natural | | | selection**\ | | | -- how species originate and | | | change through time\ | | | -- changed view of "our origin, | | | our nature and our place\ | | | in the universe"\ | | | -- increases understanding of | | | human form and function. | +-----------------------------------+-----------------------------------+ | **WALTER CANNON** | **-- 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 | +-----------------------------------+-----------------------------------+