Homeostasis: Mechanism, Regulation, and Importance

The essay discusses the mechanism of homeostasis under the light of the regulation of endocrine glands, osmo-regulation, and urinary systems. It also emphasizes the importance of homeostasis in maintaining dynamic range of environmental qualities rather than holding the internal environment at a set point.

Running head: HOMEOSTASIS
HOMEOSTASIS
Name of the Student
Name of the University
Author Note

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Introduction
The physiologist uses the term homeostasis in order to define the process of the
maintenance of nearly constant condition in the internal environment. Nearly all the tissues
and the organs of the body perform this functions that help to maintain this constant condition
(Hall, 2017). The following essay with emphasize the detail mechanism of homeostasis under
the light of the regulation of endocrine glands, osmo-regulation and urinary systems. The
essay will also help to understand how homeostasis helps to provide freedom of activity from
dependence upon the changes in the external environment. At the end, the essay will discuss
the effect of the malfunction of the homeostasis and importance of homeostasis in pregnant
women.
Discussion
Role of hormones in homeostasis
Endocrine system plays an important role in controlling and coordinating the process
of homeostasis with the body. The hormones secreted from the endocrine glands are
transported as the extracellular fluid to all parts of the body in order to regulate the cellular
function and at the same time helps to regulate the process of homeostasis for example, the
thyroid hormone and insulin (Hall, 2017).
Insulin is secreted by the beta-cells of the islet of Langerhans of the pancreas in
response of the glucose molecule in the blood circulation. The antagonist of insulin hormone
is glucagon, which is also produce by the pancreas. Glucagon aids in the process of the
glucose production and its subsequent release in the bloodstream on the other hand, insulin
promotes the absorption of the glucose molecule from the blood stream to inside the hepatic
cells (Hall, 2017). When the glucose concentration within the blood stream exceeds the

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normal threshold value, the secretion of glucagon is inhibited and insulin is secreted from the
pancreas. The inhibition of the glucagon synthesis inhibits the glucose production by
glycolysis and promotes subsequent uptake of glucose into the hepatic cells by insulin. This
regulation of the glucose production and uptake by the interplay of insulin and glucagon help
to regulate the body temperature (Hall, 2017). Disruption in the equilibrium of the synthesis
of the insulin and the glucagon molecule might lead to the development of hypoglycemia.
Hypoglycemia is an abnormal state of mind and in order to adjust the body under limited
availability of glucose, the hypothalamus of the brain reduce the body temperature,
hypothermia. Hypothermia is characterized by decrease in the blood pressure, pulse rate and
the respiratory rate (Kenny, Sigal & McGinn, 2016).
Thyroid hormone is secreted from the thyroid glands located, below the larynx. There
are two types of thyroid hormones thyroxine (T4) and triiodothyronine (T3) and the synthesis
of the thyroid hormone is regulated by thyroid stimulating hormone from the anterior
pituitary. The role of the thyroid hormone is to activate the nuclear receptors to promote cell
signaling and to aid in several metabolic activities like glucose absorption, gluconeogeneisis,
glycogenolysis. Absence of the secretion of the thyroid hormone leads to disruption in the
basic metabolic activity in the body leading to deficiency in the glucose production leading to
development of hypothermia (Hall, 2017).
Role of thermoregulation in freedom of activity from dependence upon change in the
external environment
The mechanism of the generation of heat within the body helps to keep the body
warm under the cold climatic environment and this mechanism is non-shivering
thermogenesis. In this mechanism, there occurs generation of heart within the body in
response to the cold stress in the external environment. This type of thermogenesis is mainly

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regulated by the activation of the sympathetic nervous system. Activated sympathetic nervous
system leads to release of the stress hormones epinephrine and norepinephrine. The release of
the stress hormones lead to the generation of heat inside the body (Charkoudian, 2016). In
response to the generation of heat within the body, brown fat and sympathetic nervous system
play an important role. Brown fat is rich in mitochondria and numerous small globules of fat
molecules instead to a large fat globule. In these brown fat cells, the biochemical process of
the oxidative phosphorylation in the organelle of mitochondria is “uncouple”. Thus upon the
stimulation of the cell by the sympathetic nervous system, the oxidation inside the
mitochondria lead to the generation of significant amount of heat with negligible expenditure
of ATP. This helps in immediate transformation of the oxidative energy into heat and thereby
helping to increase the body temperature in cold atmosphere. The neonates have high level of
brown fat and maximal rate of the sympathetic stimulation increases the metabolism to 100%
in comparison to the older adults (Chondronikola et al., 2016).
Homeostasis in maintaining dynamic range of environmental qualities rather than
holding the internal environment at a set point
The process of osmoregulation also maintains thermoregulation. One of the important
characteristics of mammals is ability to regulate the body temperature along with managing
the volume and composition of body fluid. A common thermoregulatory mechanism to
dissipate heat during summer is evaporative cooling done by sweating and/or panting,
however, these responses result in a reduction of total body water, hampering the osmotic
balance of the body. While sweating is an effective means of decreasing body temperature,
unless the resultant body fluid loss is replaced (water intake), hypovolemia, hypertonicity
along with circulatory collapse can ensue. The physiological control mechanisms limit
thermoregulatory fluid loss once there is a liability and sweating is prevented. Thus,
mammals will tolerate a high temperature in order to minimize future loss of body water

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(Amici et al., 2014). Osmoreceptors in lamina terminalis of the brain in inhibits sweating in
response to increased effective osmotic pressure (tonicity). Selective brain cooling (SBC) in
domesticated mammals occurs when blood flow to the brain is cooled. Thus SBC promotes
reduced sweating, thereby preserving the loss of body fluid. Behavioral response of drinking
water can increase sweating, overriding osmoregulatory inhibitory influences in the preoptic
region of the brain (McKinley et al., 2018).
On the other hand, it can be said the behavioral responses of drinking excess water
can hamper the osmotic balance in the body along with decrease in the overall body
temperature. In this scenario, the urinary system plays an important role. Drinking excess
water leads to disequilibrium in the fluid balance inside the body. This results in excretion of
excess fluid through urine. This excretion of urine leads to the stabilization of the body fluid
and thereby helping to restore the body temperature (Cianciolo & Mohr, 2015).
Homeostasis hampering external activity
However, homeostasis or effective thermoregulation can hamper external activity as
well. For example shivering provides a defined means of generation of heart by aiding to
increase the overall activity of the muscle in response to the generation of the cold stress. The
shivering hampers the freedom of activity (Charkoudian, 2016).
Homeostasis during development of new humans within the bodies of their mothers
Significant amount of the physiological alterations occur within the body of a woman
while she is pregnancy. These changes in the biochemical and physiological functioning are
important for the adaptation to pregnancy-specific physiological processes both the mother
and the fetus. The role of homeostasis during pregnancy is regulated by blood flow through
the placenta. Deregulation of these functional feto–maternal interactions leads to severe
complications (Rao, Shashidhar & Ashok, 2013).

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For example, a fatal threat in pregnancy is high blood pressure. During pregnancy,
cardiac output is increased due increased circulatory blood flow and decreased peripheral
vascular resistance. Due to dilation of maternal vessels, blood pressure is low and this permits
expansion of maternal fluid. Maternal fluid plays an important role in the prevention of
placental hypo-perfusion. Dysfunction of cardiovascular regulatory mechanisms during
pregnancy leads to high blood pressure in mother leading to decrease in the plasma volume.
Hamper in plasma volume leads to disrupts normal homeostasis that is fatal for both mother
and fetus (Cao & O'brien, 2013).
Malfunction in the osmotic regulation
Cells regulate their internal volume of the cytoplasm in response to the osmotic stress
by activation of membrane carrier proteins and ion channels. Disruption in homeostasis leads
to hamper in the regulation of the osmotic balance. Disequilibrium in the osmotic balance
leads to cell lysis and eventual death of the cells as the cells are unable to maintain their
standard volume (Gilbert & Weiner, 2017).
The cardiovascular system and homeostasis are inter-related and helps to maintain the
body temperature. An increase in the heart rate leads to increase in the blood circulation
through the skin. Proper blood circulation helps in maintaining of the body temperature
within the permissible limit. Disruption in the homeostasis might lead to increase or decrease
in the heart rate leading to heart failure (Gilbert & Weiner, 2017.
Conclusion
Thus from the above discussion, it can be said that homeostasis plays an important
role in regulating body’s internal and external mechanism. The biochemical process of
homeostasis is related with the endocrine system, osmoregulation of the body fluid within the
body and excretion of fluid through urinary system. The effective regulation of the urinary

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system helps to body to keep warm during winter and cold during summer. In the neonates,
also homeostasis plays an important role in maintaining body temperature through oxidation
of brown fat. In the fetus, the regulation of the placental blood helps to maintain normal
homeostasis. Disruption in the equilibrium in homeostasis is detrimental for body, increasing
the chance of cardiovascular stroke.

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