May 5 2014 Physiology Notes How an organism works ions and proteins Combo of anatomy biology chemistry and physics 3 important equations 1 ATP ADP Pi E reversible 2 Glucose O2 ADP ATP CO2 H2O heat 1 way process 3 CO2 H2O HCO3 H CO2 does not like to be in water HCO3 by making it more acidic does like to be in water H changes pH Body Organization Cell all have matching DNA because they are split into clones through mitosis Unspecialized undifferentiated Specialized differentiated Major Categories 1 Muscle generate mechanical force 2 Nerve initiate and conduct electrical signals 3 Epithelial regulate interactions with environment a Ex Skin lungs digestive track 4 Connective connect anchor and support a Ex Bone blood fat Tissue groupings of similar specialized cells Same 4 specialized categories as cells Organs Combinations of tissues Vary in proportion and patterns Functional Units smallest yet still works Ex Kidney nephron heart whole heart Redundancy Expansion If we need more add another functional unit Organ Systems Organs with common function Ex Circulatory system Organ systems can contain other organ systems Ex Immune system circulatory system These are just CELLULAR components Extracellular Fluid Matrix Mix of proteins and minerals Functions 1 Provide structure connectivity more important 2 Regulate info transfer Protein Types Fibers main ones like your hair almost 2D long thin 1 Collagen rope like traits cell one connected to cell 2 by collagen a Jump rope example 2 Elastin rubber band like traits a Theraband example Nonfibrous more 3D associated with carbohydrates or sugars Fluid Components 3 1 Intracellular fluid cytosol a 67 total water in cells average human 28L Extracellular Fluid EC 2 Interstitial Fluid IF fluid between cells a 26 11L most common external environment 3 Plasma Fluid in blood vessels a 7 3L Plasma 1 Interstitial fluid 2 Intracellular Fluid 1 Capillary Wall smallest of the blood vessels 2 Cell membrane These are barriers that limit movement Homeostasis Relatively stable maintenance of a body parameter dynamic constancy Ex Blood glucose level Relatively stable but rises up at meals Homeostatic Control System Set of interconnected components Purpose Keep parameter at Set Point SP Set Range goal Steady State SS parameter at SP Move away from steady state when response is needed Systems not changing could still have costs Energy is still used Not at equilibrium Equilibrium means no energy used Energy is limited so tradeoffs required Homeostatic Control System Disturbances from SS Feedback React respond to the disturbance 2 Negative Feedback opposite of disturbance direction a Returns toward steady state 2 Positive Feedback Continue in disturbance direction a Ex Child birth contractions get kid out b Moves further from steady state Proactive preparation feedforward Limits the degree of feedback required Less energy required Reflex Arc Receptor Receives stimulus External or Internal Afferent Pathway Sends message to integration center Afferent means going towards Integration Center Compare to SP If same ish then done If off then use Efferent Pathway Efferent Pathway Effector Get response physiological change Control for Homeostatic Control System HCS via signals Chemical Signals most travel through extracellular fluid Messenger Endocrine Hormone Released By Gland neuron Pathway plasma Communicates w distant effectors Paracrine Most cells IF neighbor effectors Neurotransmitter Neuron IF synapse next neighbor neuron or effector EXAM QUESTION How can we collapse these three messengers into only two groups Chemical messengers Most travel through EC Endocrine paracrine neurotransmitter Specials cases Autocrine pathway IF effector releaser Cytokine pathway IF plasma lymph Immune signals Some not based on EC fluid Gap Junctions Direct channels between adjacent cells Juxtacrines bound to cell membrane i e not released HCS Long Term Regulation Adaptation Ad trait that favors survival genetic change change in DNA Species change Acclimatization Ac resetting of SP Ex 50 feels warm in winter cold in summer Use based happens to individual Not genetic change individual change Usually reversible Exception Developmental Acclimatization Ex Drinking while pregnant messes with kid May 6 2014 Biorhythms Combo of FF Ad Ac Go to bed around same time wake up around same time Internal physiology has same schedules too Image 1 10 Ex Body temperature up during day down at night hormone level down during the day up at night Proactive rather than reactive SAVES energy Internal trigger not environmental Clock CAN be reset Environmental but within limits Ex Jetlag internal clock is not the same as local clock e g circadian annual lunar Circadian revolves around each day Annual Diet is easier in the spring fat for insulation in winter food is more abundant in summer than winter Lunar Active during daylight because sight is one of our main senses more light with full moon therefore more active Subcellular Composition Ions Have a charge electrolytes Net positive cation Ex Ca2 H Net negative anion Ex Cl Free radicals Single e in outer orbit Remove electron from another compound oxidizing We make them effective against pathogens but affects more than just pathogens Need to be neutralized antioxidants donors Ex Vitamin A Vitamin D Should be avoided when sick helpful once recovering Ex Superoxide O2 nitric oxide NO hydroxyl radical OH Molecular Bonds Covalent Sharing of e very strong bond Ex Water Not always equal sharing creates partial charges Polar Does not share equally AKA Hydrophilic lipophobic Amphipathic Having both polar sections and nonpolar sections Like dissolves like Nonpolar Shares equally AKA Hydrophobic lipophilic Noncovalent Ionic Electrical attractions of opposites Very strong bond OUT of water Very weak bond IN water dissociates Hydrogen bonding interaction with bound H Bonding of partial charges Weak bonding creates fluidity Hydrophobic avoids polar Plasma Membrane Functions Regulates movement in out when Binds chemical messengers Holds cell in EC matrix Allows for cell s shape and motility movement Allows for cell to cell contact Components Phospholipids Main building block Polar head and 2 nonpolar tails amphipathic Spontaneously form bilayer Cholesterol Amphipathic Vesicle formation Proteins 1 Integral Proteins Serve as channels receptors and anchors Amphipathic Not removable Some can go across the membrane transmembrane 2 Peripheral Proteins Impact shape and motility Change
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