Concepts Of Life Time Fitness Essay, Research Paper

? Homeostasis is the state of equilibrium in which the internal

environment of the human body remains relatively constant.? Two

excellent examples of homeostasis are how the body maintains a constant

temperature and blood pressure during strenuous physical activity or

exercise.? Although there are many other activities in the body that

display homeostasis, I will only discuss these two.

?Temperature in the human body is usually kept at approximately 37

degrees Celsius.? To maintain such a strict temperature, the body has a

few functions to combat the outside elements.? People cannot make

themselves cold as readily as make themselves hot, however I will

mention both homeostasis functions.? When the external temperature

decreases, a portion of the brain called the hypothalamus detects the

drop by means of the blood.? To compensate, the brain sends chemical and

electrical impulses to the muscles.? These impulses tell the muscles to

begin to contract and relax at very high intervals.? This is commonly

known as shivering.? The production of Adenosine Triphosphate or ATP in

the mitochondria of the muscles produces heat.? If the body temperature

does not rise immediately after this, then a second function begins.

The brain will signal the blood vessels near the skin to constrict or

narrow in diameter.? This occurs so the heat deep in the muscles is

conserved.? Since the vessels are now smaller in diameter, less blood is

needed to fill them.? Since less blood is needed through the vessels,

the heart begins to slow.? If the body remains in this slowed state,

hypothermia could result.? Hypothermia is the condition in which

metabolic processes are inhibited.? The medical world has taken

advantage of this by inducing hypothermia in patients that are

undergoing organ transplants.

?To fight temperatures higher than normal, as in exercise or on hot

days, the body reacts in the opposite way than with cold.? Again, the

hypothalamus detects the change of temperature in the blood.? The brain

signals blood vessels not to constrict, but to dilate.? This increases

the diameter of the vessels, and results in the need for more blood.

Since more blood is needed to fill the vessels, the heart pumps faster

and that causes respiration to increase.? The increased respiration will

make the body exhale some of the internal heat, like placing a fan in a

window to cool a room.? The blood vessels are dilated so the heat deep

in the muscles is easily released.? Another commonly known mechanism to

fight heat is sweating.? Sweat glands found throughout the body are

stimulated by the hypothalamus to excrete sweat and when the sweat

evaporates, the skin is cooled.? If the body is not cooled by the time

all of the internal water supply is used, it could go into hypothermia.

This is when the body becomes dehydrated and proteins begin to

denature.? Hypothermia can result in certain death if the water supply

is not immediately replenished.? Some advantages to these mechanisms are

the cleansing effect of sweating and weight loss.? Sweat, when excreted,

removes waste materials such as bacteria and water.? Fat material,

during exercise, is actually “eaten” by the body thus reducing overall

weight.

?The second example of homeostasis is blood pressure regulation.? When

the hydrostatic pressure of blood is above normal, pressure sensors in

the blood vessels tell the brain through chemical means.? The brain will

then stimulate the heart to contract or beat in slower intervals.? This

will cause less blood to enter the blood vessels and that will lower the

hydrostatic pressure.? If the pressure is lower than normal, the exact

opposite happens.? The sensors in the vessels tell the brain and the

brain will then make the heart beat faster so more blood enters the

vessels and the pressure is raised.

?The body uses many mechanisms to regulate temperature and blood

pressure.? Be it stimuli to the heart from the brain or messages from

the blood, the body maintains its internal environment through a process

called homeostasis.