Homeostasis Basics
The process of maintaining a stable internal environment despite external changes.
What is homeostasis?
Sensation from skin, joints, and skeletal muscle that you are consciously aware of.
What is somatic sensation?
These molecules bind to receptors to initiate a cellular response.
What are ligands?
A 24-hour biological cycle affecting physiology, such as sleep-wake patterns.
What is a circadian rhythm?
A higher-than-normal set point for body temperature in response to infection.
What is fever?
The type of feedback that opposes a change, maintaining stability.
What is negative feedback?
Sensation from organs such as the heart and gut that you are not consciously aware of.
What is visceral sensation?
Released into synapses in small packets, their effects are localised.
What are neurotransmitters?
The visceral response that constricts skin blood vessels to conserve heat.
What is vasoconstriction?
This chemical, produced during infection, alters the hypothalamic set point.
What is prostaglandin E₂ (PGE₂)?
Because protein function depends on optimal temperature.
Why is regulating core temperature essential for multicellular animals?
Moving your arm voluntarily is an example of this type of motor response.
What is somatic motor response?
Released into circulation, these chemicals act on any cell with the appropriate receptor.
What are endocrine hormones?
The involuntary muscle contractions that generate heat in response to cold.
What is shivering thermogenesis?
One adaptive advantage of fever in fighting infection.
Slows viral replication / enhances immune system activation.
Temperature, pH, ion concentration, solvent levels...
What are variables regulated by homeostasis?
Changing heart rate via the autonomic nervous system is an example of this.
What is a visceral motor response?
One key difference between neural and endocrine signalling.
Neural is rapid and local; endocrine is slower and systemic.
Both hormones and the sympathetic nervous system can drive this process of heat generation without muscle contraction.
What is non-shivering thermogenesis?
When uncontrolled inflammation and high fever cause organ failure, it is called this.
What is sepsis?