Examples of homeostatic processes that support life of organisms Essay

Homeostasis can be described as a composition of the internal environment controlled and always in constant state . Our body have control systems that detect and respond to any changes in the internal environment effectively . Factors that influence homeostasis including temperature , pressure , blood PH , hormone and water and electrolyte balance . Here some examples of homeostatic processes that support life of organism including baroreceptor response to acute changes in blood pressure , antidiuretic hormone release from posterior pituitary in response to changes in serum osmolality, hypothalamus response to changes in body temperature , central chemoreceptor response to changes in PaCO2 and parathyroid gland response to changes in serum calcium level .
A control system has three basic components detector , control centre and effector . The control centre receives an input from detector and integrate the information . When signal detects that an adjustment is needed , the control centre react and its output to the effector is changed .
There are various mechanisms including negative and positive mechanisms. In negative feedback mechanism , the effector only decreases the effect of original stimulus to maintain homeostasis . Example of negative feedback mechanism is human body temperature . As body temperature fall below the normal level , it transfer information to the cells in the hypothalamus of brain. After that the control centre activates mechanisms that raise body temperature (effectors) . These including skeletal muscles stimulating cause shivering , behavioural changes such as put on more blanket , wear more clothes and narrowing of the blood vessels will reduce the blood flow and heat loss from peripheries .
Example of negative feedback mechanism also including hypothalamus (in brain ) secret corticotrophin releasing hormone ( CRH) and anterior pituitary release adrenocortical trophic hormone (ACTH) to inhibit high levels of circulating cortisol . Once the cortisol output from adrenal gland falls , circulating cortisol levels are decreased .
Besides , the positive feedback the response is increased by the stimulus progressively so that the stimulus is continued the response progressively amplified . Examples of positive feedback mechanism including blood clotting process and the uterine contractions during baby's delivery . During normal conditions the uterine muscle is passive and not contracting . During labour , the hormone oxytocin released by the posterior pituitary into bloodstream in response to stimulate the contractions of the uterus . These will force the baby's head into the cervix of the uterus then stimulate greater stretch receptors at that area . When more oxytocin released , further strengthening the contractions and maintaining labour . After baby delivered , the strengthening of the cervix is greatly reduced . So the release of hormone oxytocin stops.
Another example of positive feedback mechanism is production of insulin and releasing of it into the portal circulation depend on blood glucose concentration . Once the blood glucose levels rise , insulin production also will increase as the blood glucose is clear to normal levels the production of insulin will falls .