Core Principles In Anatomy And Physiology Flashcards
Overall theme of A&P
maintaining homeostasis
Four core principles
(1) feedback loops, (2) the relationship of structure and function, (3) gradients, and (4) cell-cell communication.
homeostasis
body's ability to develop and maintain a relatively stable internal environment within normal range; This maintenance of homeostasis in the face of changing conditions requires the body to expend an immense amount of energy.
homeostatic imbalances
disturbances in homeostasis can lead to disease or death if uncorrected
body's internal environment
wide range of coordinated processes or variables, including the temperature, the chemical composition of blood and other body fluids, and many more
regulated variables
most variables in the internal environment are controlled so they stay close to a particular normal value; to prevent homeostatic imbalances
High temperature in cells
don't want enzyme to be denatured and the function won't work
imbalance in homeostasis
homeostasis is distrusted and can't be readily corrected, result in disease
Misconception 1: Negative feedback is bad for the body; positive feedback is good.
"negative" should not be thought of a bad consequence. IT IS the Direction of output of the effector cells
feedback loops
a change in a regulated variable causes effects that feed back and in turn affect that same variable; As the loops continue, this output then influences the events of the loops themselves
negative feedback loops
change in a regulated variable in one direction results in actions that cause changes in the variable in the opposite direction
positive feedback
a change in a variable results in actions that amplify the change
Negative feedback examples
temperatureblood pressure blood glucose
positive feedback examples
blood clotting and child birth
structure-function
the structure of any part of the body determines its function; this is true at all levels of organization
structure-function examples
hollow blood vessels transport blood thin lung tissues allows for rapid movement of gaseshollow, muscular urinary bladder stores the expel urine
Gradients
is present any time more of something exists in one area than in another and the two areas are connected; gradients five many of our physiological process
gradients examples
temperature gradients- lose heat the farther away you get from itconcentration gradients- is present when the amount of substance changes over a range
cell to cell communication
cell communicate and work together in a coordinated fashion, allowing the maintenance of homeostasis
examples fo cell-cell communication
nerve cell communicating directly with other nerve cells and muscle cellsendocrine cells communicating with distant body cells via chemical messengers