Homeostasis Flashcards
Homeostasis
Maintenance of constant internal environment
Process of homeostasis
Change is detected by a receptor
Input information send along afferent pathway to control center
Output information sent along efferent pathway to effector
Response of effector feeds back to influence, return variable to homeostasis
What needs to be controlled
Conc of blood glucose Conc of individual inorganic ions in blood (Ca2+) Water potential of blood and body fluids pH of blood and body fluids Core body temp Hydrostatic pressure of the blood
Conc of blood glucose, uncontrolled consequences
Too much or too little can change water potential of cells
Brain needs constant supply of glucose for respiration
Water potential of blood and body fluids consequences
Water will be drawn in or out of cells by osmosis
pH of blood and body fluids consequences
Affects enzyme, bond charges, shape of active site changes
Core body temp consequences
Affects enzyme function
Hydrostatic pressure of blood consequences
Maintain conc gradients for diffusion in the lungs, maintain supply of oxygen and glucose for respiration, removal of waste products
Low blood pressure, insufficient oxygen to brain, fainting
High blood pressure, can damage to endothelium lining of blood vessels
Advantages of homeostasis
Independence from fluctuating external conditions, activity times and ranges of climactic conditions
Components of a control system
Optimum point/set level Receptor Coordinator Effector Feedback loop
What is the optimum point/set level
The level, or the norm at which system operates
What is the receptor
Detects any deviation from the set point and informs the coordinator
What is the coordinator
Coordinates information from receptors and send instructions to effector
What is the effector
Brings about corrective measures to return system to optimum point
What is the feedback loop
Receptor detects stimulus created by the change to the system, effector brings about appropriate response
