Chapter 1: Homeostasis and Feedback Loops Flashcards
What is Homeostasis?
Constancy of the internal environment
Maintain stable internal conditions
Significant deviation from homeostasis indicates disease
How is homeostasis most often accomplished?
By negative feedback loops
What does ‘dynamic constancy’ refer to in the context of homeostasis?
Dynamic equilibrium
What is the role of intrinsic regulation in homeostasis?
Cells within the organ sense a change and signal to neighboring cells to respond appropriately. Autoregulation is built in
What is the role of extrinsic regulation in homeostasis?
The brain (or other organs) regulates an organ using the endocrine or nervous system. Target organs are innervated and/or have hormone receptors.
What is negative feedback?
A mechanism that counteracts a change to maintain homeostasis
What is positive feedback?
A mechanism that amplifies a response or process
What happens when a person becomes dehydrated?
Increase in blood osmolarity triggers release of antidiuretic hormone (ADH)
What are the components of a negative feedback loop in homeostasis? Fill in the blanks: Stimulus, ________, Integrating Center, Effector, Response.
Sensor
What triggers the release of prolactin during breastfeeding?
Pressure on mechanoreceptors in the nipple
What is a gradient?
Difference between one point and another
What are the types of physiological gradients? List them.
- Electrical gradient
- Thermal gradient
- Pressure gradient
- Chemical gradient
True or False: Matter and energy tend to flow up gradients.
False
Homeo means:
Stasis means:
Homeo means the same
Stasis means to stay
Together means to stay the same
What are 6 common things that use homeostasis?
Temperature, Pressure, Volume,
pH, Chemical levels, Waste.
Negative feedback
The ability to detect a change and enact mechanisms to resist that change.
Set Point
The average level of homeostasis
Dynamic constancy (dynamic equilibrium)
Subtle fluctuations around a set point.
What are the receptors that are a part of the body? (part of negative feedback loop)
Sensors, integrating center, effector
Sensors in negative feedback loop are
Baroreceptors
Stimulus
the change that is detected
Sensor/receptor
Detects stimulus
Integrating center
Makes an action or decision
Effector
Carries out final corrective action
