Regulation of the Internal Environment By: Tony Chung, Kani Cheung, Keng Lam, and Rebecca Yang View m.haight's map Taken in (See more photos here ) View m.haight's map Taken in (See more photos here ) View m.haight's map Taken in (See more photos here )
Thermoregulation is the process by which the animals maintain the internal temperature within a set of range.
View carpe icthus ' map Taken in Laurel Hollow, New York (See more photos here ) 40°52' 02" N, 73°27' 59" W40.867249-73.466348 View carpe icthus ' map Taken in Laurel Hollow, New York (See more photos here ) 40°52' 02" N, 73°27' 59" W40.867249-73.466348
The goal of thermoregulation is to balance the rate of heat gain and heat loss. All endotherms and some ectotherms thermoregulate. If the heat management is unbalanced, the animal becomes too hot or too cold.
To prevent this, animals have five general categories of thermoregulation adaptations: Insulation, Circulatory Adaptations, Cooling by Evaporative Heat Loss, Behavioral Responses, and Adjusting Metabolic Heat Production.
Insulation is a very energy efficient and dependable adaptation in mammals and birds that reduce the flow of heat between the animals and the environment. Some examples of insulation are feathers, hair, and fat layers.
Mammals that live in the water rely on fat layers and don’t have fur or feathers because fur and feathers loses a lot of its insulating powers when wet.
Circulatory adaptations allows animals to alter the amount of blood flowing between the body core and the skin. Circulatory adaptations are present in many endotherms and some ectotherms
One type of circulatory adaptation is the use of vasodilation and vasoconstriction. Vasodilation is the increase of the diameter of blood vessels to allow more blood flow. Vasoconstriction is the decrease of the diameter of blood vessels to reduce blood flow.
This aids in heat exchange because colder blood can be kept away from the body core and warmer blood can be kept away from the skin and near the body core.
Another type of circulatory adaptation is the arrangement of blood vessels called a countercurrent heat exchanger. A countercurrent heat exchanger is important for the reduction of heat loss in many marine mammals and birds.
Blood can either go through the heat exchanger or bypass it by going through other blood vessels. Many large, powerful swimmers need this adaptation for sustained swimming.
When the environment is warmer than body temperature, animals gain heat from the environment in addition to their own heat generated by metabolism. If nothing regulates this, the body temperature would rise too rapidly, one way to counter this is evaporative heat loss.
Animals have various adaptations to this including sweating, panting, and bathing. When water evaporates, it carries a significant amount of heat with it.
Both endotherms and ectotherms use behavioral responses to control body temperature. Ectotherms control body temperature mainly by behavioral responses, i.e. moving into shade when hot and into sun when cold.
More extreme behavioral responses include hibernation or migration.
Endotherms usually have a warmer body temperature than their environment, so they must be able to counteract the constant amount of heat loss from radiation. Animals cannot decrease their rate of metabolism so their only option is to produce more heat as they lose more heat.
In some mammals, a hormone can cause mitochondria in cells to produce heat instead of ATP, this is called nonshivering thermogenesis (NST).
Some mammals have a tissue called “brown fat” in the neck and between the shoulders for rapid heat production.
Animals can also shiver and perform NST to increase heat production by as much as 5-10 times than normal.
Common diseases and disorders involving thermoregulation
Fever —Increase in body core temperature. Fever is not an illness but a natural reaction to a number of illnesses.
Hyperthermia —Overheating of the body caused only by an external factor, as for example a hot environment, or a hot bath.
Hypothermia —A low body temperature, as caused by exposure to cold weather or a state of low temperature of the body induced by decreased metabolism .
Hypothyroidism —Hypothyroidism refers to a condition in which the amount of thyroid hormones in the body is below normal. Since the thyroid hormones are important in thermoregulation, hypothyroidism affects the body's capacity to control temperature.
37°C (98.6°F) - Normal body temperature (which varies between about 36-37.5°C (96.8-99.5°F)
35°C (95.0°F) - ( Hypothermia ) is less than 35°C (95.0°F) - Intense shivering, numbness and blueish/greyness of the skin. There is the possibility of heart irritability.
33°C (91.4°F) - Moderate to severe confusion, sleepiness, depressed reflexes, progressive loss of shivering, slow heart beat, shallow breathing. Shivering may stop. Subject may be unresponsive to certain stimuli.
becoming comatose. Shivering is absent (subject may even think they are hot). Reflex may be absent or very slight.
31°C (87.8°F) - Comatose, very rarely conscious. No or slight reflexes. Very shallow breathing and slow heart rate. Possibility of serious heart rhythm problems.
28°C (82.4°F) - Severe heart rhythm disturbances are likely and breathing may stop at any time. Patient may appear to be dead.
24-26°C (75.2-78.8°F) or less - Death usually occurs due to irregular heart beat or respiratory arrest; however, some patients have to been known to survive with body temperatures as low as 14°C (57.2°F)
39°C (102.2°F) ( Pyrexia ) - Severe sweating, flushed and very red. Fast heart rate and breathlessness. There may be exhaustion accompanying this. Children and epileptics may be very likely to get convulsions at this point.
41°C (105.8°F) - ( Medical emergency ) - Fainting, vomiting, severe headache, dizziness, confusion, hallucinations, delirium and drowsiness can occur. There may also be palpitations and breathlessness.
43°C (109.4°F) - Normally death, or there may be serious brain damage, continuous convulsions and shock. Cardio-respiratory collapse will occur.
44°C (111.2°F) or more - Almost certainly death will occur; however, patients have been know to survive up to 46°C (114.8°F).
Waste produced by animals effect the water quality and balance depending on type and qauntity
The most important waste products are nitrogenous breakdown products of proteins and nucleic acids.
The amount of waste and type of waste can create an animal’s living condition and habitat. Although some animals can change their form of nitrogenous waste depending on their adaptation to a new environment.
There are different types of waste secreted from animals Urea, Ammonia, and Uric acid.
The mammalian kidney uses its ability to adjust to both the volume and osmolarity of Urine. The kidney contains blood flow which contains nutrients that can be absorbed and circle in the circulatory system.
The mammalian excretory system (a) Excretory organs and major associated blood vessels
The mammalian excretory system (b) Kidney structures
A hormone produced in the hypothalamus and release from the posterior pituitary. It promotes water retention by the kidneys as part of an elaborate feedback scheme that helps regulate the osmolarity of the blood.
(2) Renin-angiotensin-aldosterone system (RAAS)
A part of a complex feedback circuit that helps regulate blood pressure and blood volume.
Atrial natriuretic factor (ANF)
A peptide hormone that opposes the Renin-angiotensin-aldosterone system (RAAS).
The nephron and collecting duct: regional functions of the transport epithelium The numbered regions in this diagram are keyed to the circled numbers in the text discussion of kidney function.
How the human kidney concentrates urine: the two-solute model. Two solutes contribute to the osmolarity of the interstitial fluid: NaCl and urea. The loop of Henle maintains the interstitial gradient of NaCl, which increase in the descending limb and decrease in the ascending limb. Urea diffuses into the interstitial fluid of the medulla from the collecting duct. The filtrate makes three trips between the cortex and medulla. As the filtrate flows in the collecting duct past interstitial fluid of increasing osmolarity, more water moves out the duct by osmosis, thereby concentrating the solutes, including urea, that are left behind in the filtrate.