CH 9: Internal Regulation Flashcards
What is Homeostasis?
-The various biological processes that keep body variables within a fixed range (temp, water levels, oxygen levels, protein, fat, acidity)
What is Allostasis?
-Adaptive way in which the body anticipates needs depending on a situation= helps to avoid errors
What does Maintaining temp require?
-Twice as much energy as all other activities combined
What is Basal Metabolism?
-Energy used to maintain constant body temp while at rest
What is Poikilothermic?
- AKA Ectothermic
- Body temp matches the environment
Who are Ectothermic?
-Amphibians, reptiles, and most fish
What makes some species Ectothermic?
-Bc the organism lacks the internal, physiological, mechs of temp regulation
What is Homeothermic?
- AKA Endothermic
- The use of internal physiological mechs to maintain constant body temp
Who are Endothermic?
-Mammals and birds
How can you decrease your body temp?
-Sweating and panting
How can you increase body temp?
-Shivering which decreases blood flow to the skin
What is the body temp of Mammals?
37 degrees celcius= 98 degrees farenheight
What is the advantage from muscles being hella warm?
-They’re ready for vigorous activity
Why is warmer temp NOT better?
- It requires more energy
- Proteins break their bonds & lose their useful properties
- And also bc reproductive cells require cooler temps
What does the regulation of body temp depend on?
-The preoptic area/ anterior Hypothalamus (POA/AH)
How does the POA/AH work?
- It receives input from temp receptors throughout the body
- It also receives input from the immune system
What happens if you heat the POA/AH?
-It leads to panting and sweating
What happens if you cool the POA/AH?
-It leads to shivering
What does the Immune System deliver?
-Prostaglandins and Histamines
What is Fever?
-Increase of body temp set point which is directed by the Hypothalamus
What are the benefits of Fever?
- Certain bacteria grow less vigorously
- Immune system works more vigorously
What does it mean when your fever is above 103 degrees farenheight?
-It does the body more harm than good
What does it mean when your fever is above 109 degrees farenheight?
-They are life-threatening
How much water is in a Mammilian body?
70%
What does the Concentration of Water determine?
-The rate of all chemical reactions in the body
How can water be conserved?
- Excreting concentrated urine
- Decreasing sweat
How do we regulate water?
-By drinking more water than we need and excreting the rest
What is Vasopressin?
- AKA Antidiuretic Hormone
- A hormone released by the Posterior Pituitary
What role does Vasopressin play in water regulation?
- It raises blood pressure by constricting blood vessels
- Helps to compensate for decreased water volume by enabling kidneys to reabsorb water & excrete highly concentrated urine
What are the 2 types of of thirst?
- Osmotic
- Hypovolemic