Chapters 1-2-3 - Chapter 1 Chapter The Study of Body...

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Unformatted text preview: Chapter 1 Chapter The Study of Body Function (p 4 – 10) Physiology Physiology a Study of biological functions of the body • From cell → tissue → organ → system From • Ultimate objective of physiological research is Ultimate therefore to understand the normal functions of normal cells, organs and systems cells, Homeostasis Homeostasis a Maintaining constancy of internal environment • Walter Cannon (1871-1945) • Dynamic constancy – Within a certain normal range a a Maintained by negative feedback loops Regulatory mechanisms: • Intrinsic: – Within organ being regulated • Extrinsic: – Outside of organ, such as nervous or hormonal systems – Negative feedback inhibition Feedback Loops Feedback a The loops • • Sensor – detects deviation from set point Sensor set Integrating center: Integrating – CNS or endocrine glands – Determines the response • Effector: Effector: – Muscles or glands – Produces the response a Negative feedback • • • Common regulatory mechanism for Common maintenance of homeostasis maintenance Defends the set point → reverses the Defends deviation → produces change in opposite direction direction Example – insulin and blood sugar Action of effectors amplifies the changes Is in same direction as change Example – trypsinogen and trypsin a Positive feedback • • • Primary Tissues Primary a The body composed of 4 different primary tissues: • • • Muscle, nervous, epithelial, connective tissues Epithelial tissues Connective tissues – Cells that form membranes – Provide barrier between external and internal environments – Large amounts of extracellular material in the spaces between connective Large extracellular tissue cells tissue – Examples – blood, bone, cartilage a a Organs: • • Composed of at least two primary tissues Organs that are located in different regions of the body and perform Organs related functions related Systems: Chapter 2 Chapter Chemical Composition of the Body (p 27 – 29) Water as a Polar Solvent Water a a Water is a polar solvent and tends to interact better with polar polar (hydrophilic) molecules polar Amino acids, proteins, carbohydrates, and nucleotides are Amino highly polar and ionized so that they are soluble in water (hydrophilic) (hydrophilic) Hydrophobic (Lipophilic) Substances Hydrophobic a The bulk of any lipid molecule is non-polar • Containing long hydrocarbon chains Containing long a Lipids are soluble in nonpolar solvents (lipophilic) such as such ether and benzene but are insoluble in water (hydrophobic) ether Amphipathic Molecules Amphipathic a Contain both polar (hydrophilic) head Contain both group and hydrophobic tail group in their structures structures a Soap as an amphipathic substance • • RCOO-Na+ Detergent action Digestion of lipid – bile acids (salts) Transport of lipids in the blood Functions and mechanisms of the Functions pulmonary surfactants pulmonary Cell membrane structure Absorption of lipids Entry of steroids into cells a Important amphipathic biomolecules: • • • • • • Chapter 3 Chapter Cell Structure and Genetic Control (p 52 – 55) Biological Membranes Biological a Membrane lipids spontaneously Membrane form bilayers form • The hydrophobic components The face inward, whereas the hydrophilic components face outward outward a Thin sheetlike structures Thin composed of lipid and protein composed • Membrane lipids create the Membrane permeability barrier permeability • Membrane proteins serve as Membrane pumps, enzymes, receptors, and energy transducers energy • Membranes create Membranes compartments ranging from mitochondria and nuclei to entire cells entire ...
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