Homeostasis Basics
Claude Bernard said a constant internal milieu is required for
What is good health
Blood glucose is an example of this kind of physiological variable.
What is a homeostatically regulated variable
This part of the nervous system controls skeletal muscle.
What is the somatic nervous system (SNS)?
The parasympathetic division is known as this.
What is rest-and-digest?
Blood vessels receive innervation exclusively from this ANS division.
What is the sympathetic division?
Walter Cannon defined this term: maintaining stable internal conditions despite external changes.
What is homeostasis
Homeostatic systems require these to detect deviations in the body.
What are sensors?
This division of the nervous system controls smooth muscle, cardiac muscle, and glands.
What is the autonomic nervous system (ANS)?
The sympathetic division is activated during these 5 “E” situations.
What are exercise, excitement, emergency, embarrassment, and exams?
Sympathetic activation causes these two temperature-control responses when the body overheats.
What are sweat gland activation and skin blood vessel dilation
Negative feedback does this to a physiological variable.
What is returns it to the set point?
When homeostasis is lost in one variable, it often triggers this in other variables.
What is a cascade of compensatory changes
Somatic motor neurons always release this neurotransmitter.
What is ACh (acetylcholine)?
Pupil constriction and increased GI activity are effects of this division.
What is the parasympathetic nervous system?
This brain structure is the main integrative centre for the ANS.
What is the hypothalamus
This type of feedback accelerates a process and pushes a variable away from the set point.
What is positive feedback
The structure that compares actual values with set point values in a feedback loop.
What is the control center?
In the ANS, the neuron in the CNS that synapses at the ganglion is called this.
What is the preganglionic neuron?
This division has long preganglionic and short postganglionic fibres.
What is the parasympathetic division?
This ANS “tone” slows heart rate and maintains activity of digestion and urination.
What is parasympathetic tone?
This anticipatory mechanism minimizes internal changes before they occur.
What is feed-forward control
Homeostatic mechanisms must compensate because sensors only respond within this limitation.
What is a limited range of stimulus values?
Postganglionic sympathetic neurons typically release this neurotransmitter.
What is norepinephrine (NE)?
This division produces diffuse, longer-lasting effects due to slow NT breakdown and adrenal medulla hormones.
What is the sympathetic division?
Releasing renin from the kidneys is a unique function of this system and helps increase blood pressure.
What is the sympathetic nervous system?