Homeostasis Flashcards
Homeostasis
The physiological state of the body in which internal, physical and chemical conditions are kept in a range suitable for life process
In homeostasis do we talk about the intracellular fluid or extracellular fluid? And what is it made of?
Extracellular fluid. It is composed of blood plasma and interstitial fluid
Blood plasma
The fluid part of blood
Interstitial fluid
The fluid that fills the spaces between cells and tissues
Homeostatic mechanism
(may incorporate multiple organ systems) monitors internal and external conditions and changes bodily functions to maintain homeostasis
Negative feedback mechanisms
When something in the body is too low and it sends a signal to raise it, then when it gets too high it sends a signal to lower it and so on. Ex. Thermostat
Thermoregulation
The regulation of internal temperature using the negative feedback mechanisms
Homeotherms
Animals that maintain a stable body temperature regardless of external temperatures. Also known as endotherms (humans, mamals)
Poikilotherms
Animals whos body temperature atches with external temperatures. Also known as ectotherms (fish, amphibians)
Hypothalamus
Regulates thermorugulation in humans
Hypothermia vs Hyperthermia
Hypothermia is cold Hyperthermia is hot
Hyperthermia
body temperature is elevated beyond normal because of failed thermoregulation
Hormones
chemicals released by specialized cells that affect cells in other parts of the body
Endocrine hormones and examples
chemicals secreted by endocrine glands directly into the blood ex. digestive, mucus, and sweat glands
Exocrine glands
secrete substances onto body surfaces or cavities via tubes or ducts
Non-target hormones
growth hormones, insulin and adrenaline
Targeted hormones
gastrin
Similarities and differences between the nervous system and the endocrine system
Similarities: provides integration and control of organs and tissues
Differences: nervous system has immediate response to changes where endocrine system maintains control over long periods of time.
Do hormones affect all cells?
No, cells may have receptors for some hormones and not others and the number of receptors on each cell vary
Steriod hormones
made of cholesterol
