Kin 131

• "myo" - relating to muscle (myofibre, myofilament, myopathy)
• "osteo" - relating to bone (osteocyte, osteoblast, osteoporosis)
• "pathy" - suffering or disease (neuropathy, sympathy, psychopathy)
• "iso" - meaning equal (isometric, isokinetic)
• Anatomy: the study of the physical structure and shape of the body and its components. Gross anatomy vs microscopic.
• physiology: the study if how living organisms function and the mechanisms involved
• Structure (anatomy) dictates function (physiology)
• Homeostasis is essential for health and survival - there is a necessity to maintain physiological variables within normal ranges
• physiological processes are dictated by the laws of physics and chemistry
• cellular physiology: the study of cellular functioning
• systemic physiology: the study of how whole organ systems function
• pathophysiology: the study of disease states their effect on function
• homeostasis: the dynamic process of maintaining a stable internal environment
• dynamic consistency: a given variable may fluctuate in the body in the short term but is stable and predictable in the long-term
• equilibrium: a state where the variable does not require an input of energy to maintain consistency
• steady state: a state in which a variable in a system is not changing, but energy must be continuously added to maintain a stable, homeostatic condition
• reference values: often presented as "normal ranges", available for many physiological measures
• Homeostasis steps

  1. stimulus - produces a change in variable
  2. receptor - detects change
  3. input - information is sent along the afferent pathway to the control center
  4. output: information is sent along the efferent pathway to the effector
  5. Response of the effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level
• Feedback systems respond to change after it has occurred
• feedforward systems anticipate a change and elicit a response before it happens
• positive feedback: accelerates a process by moving a variable further from a set point. example: oxytocin during childbirth
• negative feedback: minimizes changes from the set point of a system, leading to stability, ex. blood sugar regulation
• feedforward regulation: a change in a variable is anticipated, and a response is evoked to minimize fluctuations in the variable, ex. central command at the onset of an exercise
• Chemical body organization - atoms combine to form molecules
• cellular body organization - cells are made up of different molecules
• Cells - basic structural and functional unit of all living organisms, activity of an organism depends on the collective activities of its cells
• cells made up of compounds C, H, N and O
• plasma membrane - the phospholipid bilayer with hydrophobic tails and hydrophilic heads therefore selectively permeable
• membrane transport -

  simple diffusion: lipid-soluble solutes through PLB

  Osmosis: diffusion of water through aquaporin only

  facilitated diffusion: through a channel protein based on size and charge, or, via protein carrier specific for one chemical
• Endocytosis: engulfing of substances in the extracellular environment by enclosing them in a vesicle, attaches to lysosomes and spills contents
• exocytosis: ejection of substances from the cell, product released is packaged into a vesicle which fuses to cell membrane
• cytoplasm: outside the nucleus and inside the cell membrane, when most cellular activity takes place
• cytosol: fluid that suspends other elements, composed of water
• inclusions: commonly stored nutrient products that float
• organelles: the metabolic machinery of the cell
• mitochondria: double membraned organelle inside layer is folded, supplies ATP for cellular activity, highly metabolic cells, pinch in half to replicate
• Ribosomes: made up of proteins and rRNA, the site of protein synthesis, free-floating or bound to rough endoplasmic reticulum
• cytoskeleton: not an organelle, elaborate network of protein structures determines the cell shape, supports organelles, provides machinery for intracellular transport
• microfilaments: involved in cell motility, produce changes in cell shape
• intermediate filaments: resist pulling forces on the cell