Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on...
-
Upload
norma-walsh -
Category
Documents
-
view
215 -
download
1
Transcript of Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on...
![Page 1: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/1.jpg)
Human Physiology
9-1-11
![Page 2: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/2.jpg)
SweatingHypothalamus --> SNS output-->SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP) transport out of sweat gland--> Cl- follows passively--> water follows movement of ions
Skin surface
Sweat glandSNS nerve
Na, Cl, water
![Page 3: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/3.jpg)
Sweating continued….
In profuse, long-term sweating:As the Na+, Cl- and water continue up the duct toward the skin surface, K+ exchanged for Na+,HCO3- exchanged for Cl- with expenditure of ATP.
![Page 4: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/4.jpg)
Sweating, continued….When the ionic mixture reaches the skin surface, water is evaporated, leaving the ions on the skin.
Na+, Cl-, K+, HCO3-
Water
![Page 5: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/5.jpg)
Sweating is a highly effective way (600 kcal/L) of losing heat
A given amount of sweat causes much more heat loss than it cost to produce it.
The effectiveness of sweat varies with relative humidity
![Page 6: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/6.jpg)
Regulation of body temperature
Body temperature is the only homeostatically regulated variable that is not allowed to change before the regulator takes action.
The regulator takes action in response to a potential change in body temperature, not an actual one.
![Page 7: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/7.jpg)
![Page 8: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/8.jpg)
Tb --> sensors--> hypothalamus --> SNS --> sweating ( heat loss) vasodilation ( heat loss)----> Tb
Tb --> sensors--> hypothalamus--> motor --> shivering ( heat prod.) SNS -- >vasoconstriction and piloerection ( heat loss) ----> Tb
![Page 9: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/9.jpg)
Air Temperature
Metab. rate
![Page 10: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/10.jpg)
HypothermiaIf heat loss > heat production, Tb If negative feedback cannot bring Tb , then positive feedback can occur
Tb --> heat production --> Tb --> heat production --> Tb , etc.
Body temperature
LogMetabolicrate
![Page 11: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/11.jpg)
Hypothermia 98 --> 95 F extreme shivering, change in mental ability, lack of coordination, slurred speech, aggression94 F---> greatly impaired mental and physicalbelow 85 F lose ability to shiverbelow 78 F heart stops
![Page 12: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/12.jpg)
Frostbite
To protect the core body temperature, the brain may shunt warm blood away from the areas with highest heat loss (fingers,toes, nose, ears) to the core.
As area cools, skin red--> skin white--> pain--> numb--> freeze--> cells killed
![Page 13: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/13.jpg)
Hyperthermia A. fever--a regulated rise in Tb
“Pyrogens” are small proteins released by white blood cells that detect pathogens. Pyrogens then cause the production of a fever
![Page 14: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/14.jpg)
![Page 15: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/15.jpg)
Fever
Time
Tb
New set point
![Page 16: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/16.jpg)
Benefits of fever
1. White blood cells more mobile at higher Tb2. WBC’s more able to kill pathogen at higher
body temperature3. Some pathogens killed directly by higher Tb
Antipyrogens (aspirin, acetominophen) decrease set point.
![Page 17: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/17.jpg)
2. Exercise induced hyperthermia (also a regulated rise in body temperature)
![Page 18: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/18.jpg)
![Page 19: Human Physiology 9-1-11. Sweating Hypothalamus --> SNS output--> SNS releases acetylcholine (ACH) on sweat glands--> stimulates Na+ active (with ATP)](https://reader030.fdocuments.in/reader030/viewer/2022032805/56649eeb5503460f94bfcf86/html5/thumbnails/19.jpg)
HyperthermiaC. heat stroke (unregulated rise in body temp) If heat loss < heat production + heat gain from environment, Tb If negative feedback cannot bring Tb , then positive feedback can occur
Tb --> heat production --> Tb --> heat production --> Tb , etc.
Body temp.
Log metab. rate