Lecture 1 Tuesday August 30 2012 Syllabus Review Systems Homeostasis and Feedbacks Slide 13 Levels of Organization Cells Smallest living unit Tissues collection of cells of the same type Organs Collection of two or more types of tissues put together into structures that perform a specific function Organ Systems Collection of organs that work together to accomplish a particular task Organization o Atoms molecules cells tissues organs organ systems organisms populations of one species ecosystem of different species biosphere o See Diagram for organization Slide 14 Primary Cells Tissue Classes Over 2000 types of cells divided into 4 general categories o 1 Muscle contraction generation of force Skeletal smooth cardiac o 2 Connective connect anchor support o 3 Epithelial barrier between body and external environment Blood bone exchange o 4 Nerve initiate transmit electrical impulses Slide 15 Body Fluid Compartments For a 70 kg man total body water 42 liters o 28 L intracellular fluid ICF o 14 L extracellular fluid ECF 3 L plasma fluid that the blood dissolves in 11 L interstitial fluid ISF all the ECF except for plasma all the other cells in the body are surrounded by this substance Intra inside of the cells Extra outside the cells Slide 16 Body Systems we will be Covering What is in out book may not be the same as other things Some things are classified different ways Slide 17 Immune and Lymphatic System Returns fluids to blood vessels Cleanses the blood Protects the body from pathogens Housekeeping o These are cells that destroy mutated cells mutated cells could multiply and cause cancer if not taken care of Regulates ECF Parts Slide 18 Cardiovascular System Transports material in body via blood pumped by heart Need to regulate oxygen because the body needs the oxygen to o If this is not regulated it creates acid called carbonic acid Maintains blood plasma pH in the human body it is 7 4 o This is important because the body s proteins function at a certain pH o A change in pH will change the shape of protein which will therefore change the function of the protein o Thoracic duct o Lymph nodes o Lymphatic vessels o Oxygen generate ATP o Carbon dioxide Waste product o Nutrients o Wastes Parts o Heart o Blood Vessels Slide 19 Respiratory System Keeps blood supplied with oxygen Removes carbon dioxide 7 4 Parts o Nasal Cavity o Pharynx o Larynx o Trachea o Bronchus o Left Lung Slide 20 Urinary System Eliminates waste Maintains acid base balance Regulates water and electrolytes Parts o Kidney o Ureter o Urinary bladder o Urethra Slide 21 Reproductive System Produces offspring Not required for homeostasis o Required so that the human species could survive Parts o Seminal vesicles o Penis o Prostate gland o Vas deferens o Testis o Scrotum o Mammary glands in breasts o Uterine tube o Ovary o Uterus o Vagina Slide 22 Digestive System Breaks down food Allows for nutrient absorption into blood Eliminates indigestible material fecal matter o This is not waste waste is in the urine Slide 23 Interrelationships Among Body systems See Diagram Failure of 1 system effects the other systems Integrated systems works together o Stable body temperature o Maintain blood pressure o Maintain blood pH o Maintain water balance osmolarity o Stable blood sugar levels Slide 24 Homeostasis Is A Central Organizing Principle of Physiology Is the process of maintaining stable internal environment compatible for life Homeostasis steady state Exception reproductive system Most organ systems contribute to homeostasis Negative Feedback Control in Homeostasis Homeostasis in Action Thermoregulation and Negative Feedback Slide 25 Homeostasis Homeostasis is used for the maintenance of a stable internal environment A Dynamic State of Equilibrium steady state Homeostasis is necessary for normal body functioning and to sustain life Homeostatic imbalance A disturbance in homeostasis resulting in disease if not corrected Negative Feedback Control is used to maintain homeostasis Most organ systems contribute to homeostasis the exception is the reproductive system Changes in homeostasis can be internal or external See Diagram Slide 26 Maintaining Homeostasis through Neural and Hormonal Control System Receptor sensors o Responds to changes in the environment stimulus o Sends information to the control center o Detects levels of regulated variable and provide input to integrating center Control center integrating center o Determines set point usually in the brain desired level of regulated variable and analyzes information o usually in the brain compares set point to actual level of regulated variable and sends output to effectors to return regulated variable to set point o determines appropriate response Effector o Provides a means for response to the stimulus sense changes tells brain fixes problem Slide 27 Negative Feedback Control in Homeostasis Primary mechanism for maintaining homeostasis Body s response to the original stimulus is to offset it so that it is within normal physiological set points External change triggers change in a regulated variable in internal environment this triggers a reaction to oppose the dectected change and return regulated variable toward normal parameters set point Example of Negative Feedback o Radiant cooling increase in blood flow to skin and skeletal muscles to get rid of heat See Diagram for Negative Feedback loop o The end result will always be the opposite Slide 28 Homeostasis Seesaw See Diagram Slide 29 Thermoneutral Zone and Normal Body Temperature is 37 degrees C Thermoneutral zone if the range of outside temperature where alterations in blood flow alone regulates body temperature 25 30 degrees C o This temperature is low because it allows us to get rid of extra heat Body temperature increase blood flow to skin increases o Radiated cooling Body temperature decrease blood flow to skin decreases o Diverting blood away from skin to conserve the blood around the core o Shivering increased body temperature because it generates heat See Diagram Slide 30 Positive Feedback Loop Positive feedback loops cause a rapid change in a variable Not a common mechanism for maintaining homeostasis Response increases the original stimulus as opposed to canceling it out Stimulus must end for response to end Examples o Labor breast feeding blood clotting Slide 31 Positive Feedback Loop After a heart attack a portion of the heart tissue dies and scar tissue forms The heart has to increase the its heart rate
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