Anatomy and Physiology Summer 2015 Chapter 1 An Introduction to the Human Body Six Levels of Structural Organization 1 Chemical Level atoms to molecules 2 Cellular Level molecules are organized into cells 3 Tissue Level groups of similar cells work together i Example endocardium epithelial and muscle cells 4 Organ Level two or more tissues become an organ 5 System Level related organs work together to preform a common function i Example cardiovascular system heart and 3 blood vessels 6 Organism Level all of the cells tissues and organ systems become a human being Systems of the Body Muscular System o Components muscles composed of skeletal muscle tissue o Function production of body movement Nervous System o Components Brain Spinal Cord and nerves o Function generates action potentials to regulate body activities Endocrine System o Hormone regulation Cardiovascular System o Components Blood heart and vessels o Function pump blood through vessels Lymphatic System and Immunity Respiratory System o Components Lungs trachea larynx and bronchial tubes o Function transfer oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air Digestive System o Components mouth pharynx esophagus stomach intestines o Function chemical breakdown and absorption of food HOMEOSTASIS Balance Equilibrium Key Principle Maintains relatively constant conditions in the body o Although conditions within the body are stable this is a result of many dynamic processes that constantly adjust internal activities to match changing needs HOMEOSTASIS Examples glucose levels blood pressure body temp Changes in body small homeostasis reached soon and everything is okay o Example donating blood heart rate after exercise Changes in body large die or attempt to reach homeostasis brings about a disease o Example loosing 2 3 L of blood go to hospital can t cont normal activities may even die General Process stimulus produces a change in the variable a receptor detects the change sends message of change to via afferent pathway to control center Control Center decides the action that needs to be done sends action plan along efferent pathway to effector Effector preforms the job needed to restore homeostasis if variable increases then homeostasis regulation is to decrease Vocabulary Check Receptor detects change in homeostasis Afferent Pathway pathway in which information is sent from the receptor to the control center Control Center analyzes the imbalance that is occurring and decides what needs to be done to restore balance Efferent Pathway pathway in which information is sent from the control center to the effector Effector preforms the task decided by the control center Is responsible for inducing the effect needed to restore homeostasis Body Fluids carefully regulated Our body fluids include The volume and composition of the various fluids within our bodies are o Intracellular fluid the fluid inside our cells o Extracellular fluid all body fluids other than the ones inside our cells Can be subdivided according to location Interstitial fluid the fluid between cells in tissues Plasma the fluid component of blood Lymph the fluid in our lymphatic vessels Cerebrospinal Fluid CSF the fluid within the CNS Synovial fluid the fluid within most joints Feedback Systems Control our Internal Environment act to stabilize the body in the face of changing external and internal conditions o Negative feedback systems cause an opposite response to the initial change and so are self limiting o Positive feedback systems the response is the same as that caused by the initial change An outside event must break the positive feedback cycle Negative Feed Back System Three essential components o Receptor detects changes in controlled conditions o Control center decides the type and amount of response required o Effector reacts to signals from the control center and produces the required response The term negative feedback is used because the response is opposite in direction to the original change Example blood pressure regulation o Three essential components Baroreceptors receptor detect changes in blood pressure and communicate with the brain The brain control center interprets information and sends signals to the heart and blood vessels Heart and blood vessels effector alter their activities based on signals from the brain o Resulting in the blood pressure being restored to normal Another Example Blood Glucose regulation o High glucose hyperglycemia insulin secreted o Low glucose hypoglycemia glucagon secreted Positive Feed Back System 5 12 Reinforces effect of stimuli Main Example Child Birth Start of 5 14 Lecture Power Point Chp 3 Chapter 3 Cell Biology and Genetics Basic Structure of the Cell Cell Membrane separates the intercellular and extracellular fluids o Many ions electrolytes Na K Ca 2 o Inside and outside of the cells Intracellular Fluid contains organelle o Endoplasmic Reticulum o Mitochondria contains a membrane o Golgi Apparatus Plasma membrane the flexible outer surface of the cell Cytoplasm contains numerous organelles surrounded by cytosol Nucleus large organelle that contains the cells chromosomes Plasma Membrane Separation of intracellular vs extracellular materials Production of charge difference membrane potential across the membrane by regulation of intracellular and extracellular ion concentrations o Outside of membrane positively charged compared to inside because of gathering ions along outside and inside Plasma Membrane cont Components o Proteins o Lipids o Carbohydrates NOT IMPORTANT Fluid Mosaic Model made of Phospholipids Membrane Lipids o Phospholipids bilayer fluid nature of the membrane o Fluid nature provides allows Distribution of molecules within the membrane Phospholipids automatically reassembled if membrane is damaged Membranes can fuse with each other Membrane Permeability Polar heads facing water in the interior and exterior of the cell hydrophilic hydrophobic Nonpolar tails facing each other on the interior of the membrane o Cholesterol interspersed among phospholipids Amount determines Small and or non polar molecules are able to pass easily through phospholipid bilayers The permeability of membranes to ions polar molecules depends on the number of specific transport proteins How quickly ions and molecules cross membranes depends on o The concentration gradient of the ion molecule most influential force moving with high to low concentration against low to high concentration and
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