Thermoregulation in Aves
Like some electrical appliances, the body also has a "thermostat" to help keep the temperature constant. This is known as the Hypothalamus. This heat controlling centre is particularly sensitive to two types of stimuli. These are changes of temperature of the blood and a series of impulses from the aprts of the skin that are exposed to the aterered temperature of the surroundings.As soon as the temperature of the surrounds drop, the body tends to lose heat more quickly then it can be produced. This then sends a message to the hypothalamus. Impulses are sent to the involuntary muscle layer in the small bloodvessels in the skin
The expiration of water vapour increases the rate of evaporation in the lungs. More blood flows near the surface of the body; therefore more heat loss is possibl. The skin muscles will also contract, erecting root hairs. This is accomplished by an increase in muscle tone, which requires mroe energy; consequently more oxidation occurs in the muscle cells. In this way the body keeps a constant temperature of 36. Should more heat be necessary, more impulses are sent and thus the person will start to shiver. The sweat glands produce less sweat ; consequently less sweat evaporates from the surface of the skin and less cooling occurs. Panting also helps the body to regulate temperature. The hormone thyroxin also influences the production of head. Les blood flows through the skin and consequently less heat is lost by conduction, radiation, etc. Should this not be sufficient, the production of heat is limited by loweing of muslce tone and thus the individual becomes less active. As a result the bloodvessels become narrower. More blood is supplied to the sweat glands so they secrete more sweat and evaporation occurs more rapidly. Expired air is warmer then inspired air.
Common topics in this essay:
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Behaviour Sweat,
Size Heat,
heat loss,
temperature surroundings,
hairs air,
rate heat,
blood flows,
impulses sent,
regulate temperature,
heat production,
sweat glands,
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