what is the role of homeostasis in the human life process?

Answer 1

Homeostasis maintains the body's internal environment so that the human body can create a constant dynamic equilibrium.

Our body needs to have the right amount of stuff (i.e., temperature, blood glucose, pH etc.) at all times in order to function properly. Most of the physiological processes that occur in your body are designed to maintain homeostasis.

Homeostasis works by 2 mechanism. The positive and negative feedback. Positive feedback would tell the body to continue producing or doing something to achieve the state of equilibrium while the negative feedback does the otherwise. An example of positive feedback would be the coagulation of blood where the body would constantly "fill up" the "hole" by fibrin and an example of negative feedback would be thermoregulation. When the body temperature is too high, the body would produce sweat to reduce the temperature.

Answer 2

How do the skeletal, muscle and integumentary systems interact to preserve homeostasis in the human body?

All the body systems contribute to homeostasis through a complex web of interactions with each other, and it is difficult to disentangle three systems for consideration as if in isolation. However, here are examples of homeostatic links between the skeletal, muscular and integumentary systems.

The skin interacts indirectly with the skeletal system by being one of the sources of vitamin D. Within skin exposed to sunlight, vitamin D is synthesised from a precursor molecule and transported to the digestive tract where it is needed. Vitamin D enables the uptake of calcium from our diet, and of course calcium is a key constituent of bone. The mineral component of bone matrix contains a modified form of calcium phosphate known as calcium hydroxyapatite, and if there is insufficient uptake of calcium then bone formation will be adversely affected. (Vitamin D is also present in some food materials, and this can compensate for a potential deficiency in climates where sunshine is scarce.) So the skin contributes to calcium homeostasis and skeletal health.

Because of its composition, bone acts as a calcium reserve, and there are times when calcium must be mobilised from bone tissue for use by other systems. For example, it is very important for normal muscle function that there is the correct level of calcium ions in the blood and tissue fluids - too much or too little calcium can compromise muscle activity. Therefore, the skeletal system also contributes to calcium homeostasis.

Muscular activity requires a source of energy and this comes predominantly from glucose delivered via the blood stream and glycogen stored within the muscle cells. When muscles are working aerobically, there are several by-products: heat, carbon dioxide, and water. The heat produced by active muscles helps to maintain body temperature, so muscle is contributing to heat homeostasis. However, if more heat is being produced than is needed, as for example during vigorous exercise, the excess heat has to be lost from the body to prevent a harmful rise in body temperature and the potential development of heat stroke.

This is where the integumentary system can help - the large surface area of the skin makes it ideal for temperature regulation, and excess heat can be dissipated by radiation, conduction, and convection. The rate of heat loss can be modulated by increasing or decreasing the amount of blood flowing through blood vessels in the dermis close to the surface of the skin. Skin blood flow is regulated by the temperature-regulating centre in the hypothalamus, which directly influences sympathetic tone in dermal blood vessels. When the body temperature rises, as for example during exercise, sympathetic tone is reduced and this brings about dilatation of the blood vessels supplying the skin. The increase in skin blood flow allows heat to be lost more rapidly so that body temperature does not rise above the normal homeostatic range. The rate of heat loss can also be boosted by the production of sweat, which takes up additional heat as it evaporates. Conversely, if heat production is less than required, the dermal vessels constrict, sweating stops, and heat is conserved by the body. So the skin contributing to heat homeostasis.

From these two examples - heat and calcium - it can be seen that the skeletal, muscular, and integumentary systems work together to maintain homeostasis.