homeostasis in humans Flashcards
what is homeostasis?
the maintenance of a constant internal environment, which is made up of extracellular fluid and blood plasma
what are the optimal ranges for core temp, blood pH and bgc?
core temp: 37 degrees celsius
blood pH: 7.3-7.5
bgc: 70-110mg per 100mL of blood
how does homeostasis work?
- detecting the stimulus
- receptor detects the stimulus, a receptor can only detect one type of stimulus - processing the stimulus
- signal is sent to the control centre. if the change is very small and will not cause harm to the organism, it can be ignored. if the stimulus is outside the optimal range, the CC sends a message to the effector to do something - responding to the stimulus
- the effector reacts to the stimulus
- the response is the change caused by the action of the effector
what is negative feedback?
after the primary response has occurred, a new signal is sent to stop the response from continuing.
what is positive feedback?
- occurs when the response increases the strength of the original stimulus
- generally, positive feedback is a sign of illness in the organism and can be very harmful. healthy PF involves childbirth.
why is homeostasis important?
1) enzyme activity
- since enzyme function is affected by cell conditions, it is best that the environment of the cell is maintained within the optimal limits of its enzymes
- protein shape is dependent on many factors. if the tertiary structure is denatured, the active site cannot function. the catalytic activities of this enzyme are now diminished
2) maintaining cellular respiration
- all cells must be supplied with glucose and oxygen at an appropriate rate in order to keep up with the energy needs of the cells.
3) keeping toxic substances at low concentrations
- carbon dioxide formed by cellular respiration forms an acidic solution in your blood. if not removed from the body, the cellular cytoplasm and bodily fluids will become acidic.
