Principles of Homeostasis
The name for the desired value of a physiologically-relevant variable (e.g., temperature).
What is a set point (or set range)?
For short-term storage, glucose can be converted to this, which is comprised of several glucose molecules joined together.
What is glycogen?
This is the primary region of the hypothalamus implicated in appetite control.
What is the arcuate nucleus?
This is a biological rhythm whose period is longer than 1 day.
What is an infradian rhythm?
This is the pathway by which information about light reaches the suprachiasmatic nucleus of the hypothalamus.
What is the retinohypothalamic pathway?
This is the part of a control system that can act on the variable of interest.
What is an effector?
Although this pancreatic hormone is required for the peripheral system to use glucose as a fuel source, the brain is able to use glucose without it.
What is insulin?
This hormone is released by fat cells and is an appetite suppressant.
What is leptin?
This is the process by which circadian rhythms are shifted.
What is entrainment?
This is the special light-sensitive molecule found in retinal ganglion cells that makes them sensitive to light.
What is melanopsin?
A comparator compares the actual value of a variable to the "ideal" value, and generates this signal.
What is an error signal?
These specialized cells, found in the liver and the hypothalamus, directly measure the amount of glucose in the blood.
What are glucodetectors?
This hormone is released by endocrine cells of the stomach, and is an appetite stimulant.
What is ghrelin?
This is any cue that an organism can use to align its behavior with the environment.
What is a zeitgeber?
Taking this substance might help humans to more quickly entrain their circadian clocks.
What is melatonin?
This is the name of the branch of science that studies both engineered and biological negative feedback control systems.
What is cybernetics?
This is the malfunction that leads to Type I (Juvenile onset) Diabetes.
What is the body's (or pancreas') inability to produce insulin?
When these neurons in the arcuate nucleus are active, they inhibit neighboring POMC neurons.
What are NPY neurons?
This is a type of behavioral test one might use to measure circadian activity in a rodent.
What is wheel running?
In reptiles and birds, the circadian clock is entrained by photoreceptors on this brain structure.
What is the pineal gland?
This method of temperature regulation is especially important for ectotherms ("cold-blooded" animals).
What is behavioral temperature regulation?
Although the brain prefers to use glucose as an energy source, under conditions of starvation, it is able to switch to using these, which are generated from the breakdown of fat.
What are ketones?
This happens if the combined activity of the arcuate nucleus neurons activates the orexigenic nucleus of the lateral hypothalamus.
What is there is an increase in appetite and food intake?
This happens to the circadian cycle is humans live in the dark for an extended period of time.
What is it lengthens slightly (to about 25 hours)?
What is inhibit the activity of the Clock/Cycle dimer?