8.1 Homeostasis (CQ - exam) Flashcards
what is homeostasis
maintaining constant internal environment despite changes in the external environment
what do organ systems do
work together to perform functions necessary to sustain and maintain the human organism
how are human body systems classified?
organized into groups based on functions with a common purpose
what does circulatory & lymphatic systems do?
both transport materials throughout the body
what does digestive, respiratory, and excretory systems do?
add/remove substances from blood
what does the muscular, skeletal and integumentary systems do?
help protect and support the internal system
what does the nervous and endocrine systems do?
coordinate/regulate the function of other systems
homeostatic controls are used to regulate
- water balance (osmosis)
- food/waste (diffusion, active transport)
- temp and pH (protein/enzymes sensitivities)
- cellular activity (biochemical metabolism, cellular respiration, DNA replication, cell division, protein synthesis, etc.)
components of a feedback system
- sensor/receptor
- control centre
- effector
what does the sensor/receptor do?
detects change and sends messages to a control centre
what does the control centre do?
- sets range of values that need to be maintained
- receives info from sensors and relays info to effectors
what does effectors do?
receives signals from the control centre and responds to result in change.
negative feedback
- the body works to reverse a change detected in a variable so that the variable is brought to within a normal range
- most of the body systems use negative feedback
positive feedback
- moves body systems even further away from the steady state
- has definitive cut-off points to stop amplification of the response
- less common in biological systems
