Analysis of Homeostasis, Feedback, and Hormone Action in Biology

This report provides a detailed analysis of the endocrine system, focusing on homeostasis and feedback mechanisms, and the action of hormones. It begins by explaining the principle of homeostasis, emphasizing its importance in maintaining a stable internal environment through the regulation of body temperature, water levels, glucose levels, and nitrogenous waste. The report then discusses positive and negative feedback loops, illustrating their roles in maintaining stability or driving change within the body, using blood sugar control as a key example of a negative feedback system. Furthermore, the report delves into the molecular processes of steroid and peptide hormones, outlining their mechanisms of action and the need for specificity, exemplified by oestrogen and oxytocin. Finally, it differentiates between fat-soluble and non-fat-soluble hormones, providing examples like progesterone and adrenalin, and explaining their distinct mechanisms and functions within the body.

Biology Endocrine System

BIOLOGY ENDOCRINE SYSTEM
1
Part 1: Understand homeostasis and feedback mechanisms
A) The principle of homeostasis
Homeostasis is a kind of process in which the body maintains a stable internal
environment and it is the very significant approach for the body to control the function
of the cells (Blau, et al., 2015). It is observed that it has the potential to control and
manage the stable internal environment and there are many things which require to be
regulated which are described below:
The temperature of the human body system: If the temperature were permitted to
increase out of control, protein and therefore enzyme, construction would be
exaggerated.
The quantity of water within the body system: it is observed that the level of water can
impact on human metabolism and osmosis.
The quantity of glucose in the body system: this level can also impact the osmosis of the
human body.
The percentage of nitrogenous waste in the entire body system: it is identified that
nitrogenous waste can become toxic in the body and it is very this level does not get too
high. The homeostasis contains main four steps in their principle, for example, excess,
corrective, norm, and deficiency.
Figure: homeostasis process
(Source: Dibb, et al., 2007)

BIOLOGY ENDOCRINE SYSTEM
2
B) Feedback mechanisms
Feedback is a kind of condition when the output of a loop impacts or influences in
applied signals or input value. There are main two kinds of feedback system used in the
field of homeostasis, for example, positive feedback loops and negative feedback loops.
Positive feedback loops
In such kind of feedback system, the change in a given direction causes an additional
change in the same way. For example, improve in the concentration of a substance
causes feedback which also produced continued improvement in concentration. Mainly,
such kind of systems is unstable because a change in the input signal can produce a
change in the same direction. It also increases the issue of runaway condition and in a
few cases the positive feedback system is more harmful (Turrigiano, 2012).
Figure: a positive feedback system
(Source: Humphrey, Dufresne, and Schwartz, 2014)
Negative feedback loops
In such kind of system, a change in the given direction causes a change in the opposite
direction. For example, improve in the concentration of a substance causes feedback
which also affects the concentration of the substance. It is observed that negative

BIOLOGY ENDOCRINE SYSTEM
3
feedback systems are more stable as compare to the positive feedback system and it
affects the variables which oscillate around the set target. For example, negative
feedback system includes insulin and glucagon which can help for controlling of blood
sugar in the human body system (Turrigiano, 2007). A recent study observed that, if the
glucose levels get too high then the human body releases insulin into the bloodstream
and if it gets too low then the body system releases glucagon that causes the release of
glucose from few of the body’s cells. Blood sugar control is one of the best examples of
the negative feedback system in which the control centre secretes insulin into the blood
more effectively.
Figure: a negative feedback system
(Source: Pozo, and Goda, 2010)
Part 2: Understand the action of hormones
A) Two molecular processes
There are two kinds of hormones occur in human body systems which are described
below:
 Steroid hormones

BIOLOGY ENDOCRINE SYSTEM
4
 Peptide hormones
Steroid hormones
Steroid hormones are lipophilic which can diffuse across the plasma membrane of a cell
and it can be divided into main two classes, for example, sex steroids and
corticosteroids. It has the potential to control and manage the metabolism, immune
functions, development of sexual characteristics and inflammation (Nair, Verma, and
Singh, 2017). It is observed that such kinds of hormones are transported with the help
of blood which bound to carrier proteins and enhance the hormones in water. There are
many examples of steroid hormones such as sex hormone binding globulin, albumin,
corticosteroid globulin and many more. A recent study identified that any group of
hormones which belong to the class of chemical compounds called as steroids and they
are secreted through main three glands cortex, ovaries and testes (Neeb, et al., 2015).
Peptide hormones
A peptide hormone is also called as protein hormones that molecules are peptides and it
also impacts on the endocrine process of animals. It is observed that such kinds of
hormones are synthesized in cells from amino acids according to MRNA transcripts. It is
a part of the protein which is bound by receptor and it has the potential to enable or
disable the pathway of a biological system. they have a very short life which breaks very
quickly and it allows organisms to utilize peptide hormones to direct processes more
effectively. The peptide can be initiated in pests, all vertebrates, and many other mortals
and few hormones are identified in extracellular systems. There are numerous
examples of peptide hormones such as insulin, protein kinases, NO, and many more.
B) Outline the need for specificity
Oestrogen is one of the best examples of steroid hormones and in the field of peptide
oxytocin is a very common example which uses the functions of peptide hormones
(Porcu, et al., 2016). It is identified that oestrogen is a woman sex hormone that plays a
significant role in the human body system. Having too little and too much oestrogen can
cause the range of various medical situations and both men and women produce
oestrogen hormone in their body system. In the body of the female such kind of
hormone is required for puberty, pregnancy, bone strength, and menstrual cycle and it
also impacts on the human skin, heart and brain system. The recent survey evaluated

BIOLOGY ENDOCRINE SYSTEM
5
that the level of oestrogen changes according to the menstrual cycle and also depends
on the stage of life and it is very lowest at the time of period in the female body.
Oxytocin is a part of peptide hormone which is produced through the periventricular of
the hypothalamus and it released with the help of posterior pituitary. It plays a
significant role in the area of sexual reproduction, social bonding and at the time of
childbirth. Such kind of systems are released into the bloodstream for stretching of the
cervix and uterus at the time of labour and it provides a platform to control and manage
the birth and bonding with the child and milk construction. It is mainly developed in the
hypothalamus and released at the time of sex and it affects the social behaviour and
emotion of women and men.
C) Fat-Soluble Hormones and non- Fat-Soluble Hormones
Non-fat soluble is also called as water soluble hormone which is a part of the
hydrophilic system and it is mainly dissolved in water as compared to oils or fats. It is
discussed that such kind of soluble hormones are formed from amino acids which can
be easily dissolved in water (Shahjahan, Doi, and Ando, 2016). It also affects the cells of
body system through binding to receptors on the edge of the board cell and design of
the receptor must match the shape of the signalling molecule. Adrenalin is one of the
best examples of water soluble hormones that secreted through the adrenal medulla.
The impacts or adrenalin are very similar to the impacts of noradrenalin and it also
makes the human body system for the fight. The actions of adrenalin involve:
 Metabolic rate enlarged
 The action of heart amplified
 The rate of breathing augmented
Fat soluble hormones are also called as lipid soluble which are lipophilic and mainly
dissolve in fats as compared to the water. Generally, such kinds of hormones are
produced with the help of cholesterol molecules and it can easily transfer by cell
membranes. Progesterone is the very best example of fat soluble hormones which is a
part of steroid hormone which is secreted through the ovaries. It has the potential to
control and manage the female sexual development and progressions and it is
manufactured by the corpus luteum of the ovaries. The actions of the progesterone
involve:

BIOLOGY ENDOCRINE SYSTEM
6
 Making the inner lining
 Preserving the uterus
 Avoiding further release of spawns from the capsules throughout gravidity

BIOLOGY ENDOCRINE SYSTEM
7
References
Blau, J.E., Abegg, M.R., Flegel, W.A., Zhao, X., Harlan, D.M. and Rother, K.I., (2015) Long ‐
Term Immunosuppression After Solitary Islet Transplantation Is Associated With
Preserved C‐Peptide Secretion for More Than a Decade. American Journal of
Transplantation, 15(11), pp.2995-3001.
Dibb, K.M., Graham, H.K., Venetucci, L.A., Eisner, D.A. and Trafford, A.W., (2007) Analysis
of cellular calcium fluxes in cardiac muscle to understand calcium homeostasis in the
heart. Cell calcium, 42(4-5), pp.503-512.
Humphrey, J.D., Dufresne, E.R. and Schwartz, M.A., (2014) Mechanotransduction and
extracellular matrix homeostasis. Nature reviews Molecular cell biology, 15(12), p.802.
Nair, R.R., Verma, P. and Singh, K., (2017) Immune-endocrine crosstalk during
pregnancy. General and comparative endocrinology, 242(2), pp.18-23.
Neeb, L., Anders, L., Euskirchen, P., Hoffmann, J., Israel, H. and Reuter, U., (2015)
Corticosteroids alter CGRP and melatonin release in cluster headache
episodes. Cephalalgia, 35(4), pp.317-326.
Porcu, P., Barron, A.M., Frye, C.A., Walf, A.A., Yang, S.Y., He, X.Y., Morrow, A.L., Panzica,
G.C. and Melcangi, R.C., (2016) Neurosteroidogenesis today: novel targets for
neuroactive steroid synthesis and action and their relevance for translational
research. Journal of neuroendocrinology, 28(2), pp. 12-14.
Pozo, K. and Goda, Y., (2010) Unraveling mechanisms of homeostatic synaptic
plasticity. Neuron, 66(3), pp.337-351.
Shahjahan, M., Doi, H. and Ando, H., (2016) LPXRFamide peptide stimulates growth
hormone and prolactin gene expression during the spawning period in the grass puffer,
a semi-lunar synchronized spawner. General and comparative endocrinology, 227(5),
pp.77-83.
Turrigiano, G., (2007) Homeostatic signalling: the positive side of negative
feedback. Current opinion in neurobiology, 17(3), pp.318-324.

BIOLOGY ENDOCRINE SYSTEM
8
Turrigiano, G., (2012) Homeostatic synaptic plasticity: local and global mechanisms for
stabilizing neuronal function. Cold Spring Harbor perspectives in biology, 4(1),
p.a005736.