Questions:
1. The structure and function of the endocrine system?
2. The regulation of blood glucose level, including the role of glucagon and insulin?
3. The effects of hormone imbalance, using underactive thyroid as an example?
4. Comparison between the nervous system and endocrine system?
Answers:
The structure and function of the endocrine system
The endocrine system is the summation of glands responsible for producing and secreting chemical substances and hormones in the circulatory system and have the function of regulating the activity of organs or cells. The hormones regulate the metabolism, growth of the body, and sexual function and development and tissue function (Zarrow, 2012). The main endocrine glands are the pituitary gland, thyroid gland, pineal gland, ovaries, pancreas, testes, adrenal gland and gasterointestinal tract. Even though the hormones secreted by the endocrine glands are circulated throughout the body, different hormones have the target towards different tissues and organs. The endocrine system also gets help from the other organs like heart, liver and kidney that have some secondary endocrine functions (Melmed et al., 2015).
The primary function of the endocrine system is to secrete hormones directly into the blood stream. This makes sure that all the important and vital functions of the body are controlled and maintained. The different hormones secreted by the endocrine system have different functions. For example, pituitary gland control blood pressure, stimulate the adrenal gland, control growth, stimulate milk production, stimulate secretion of hormones of the thyroid gland. Thyroid gland regulates metabolic rate and calcium (Strauss & Barbieri, 2013). When the hormone is secreted, it reaches the target cells from the the endocrine gland. The target cells have receptors latching onto the hormones. When the hormone has reached the target cell, the receptors get locked and the receptor-hormone combination transmit the chemical instructions to the workings of the cell. With the presence of hormone levels at a certain normal amount, the endocrine system helps the body in keeping that hormone level in the blood (Nussey et al., 2013).
The regulation of blood glucose level, including the role of glucagon and insulin
The regulation of the blood glucose is done by the endocrine system, more specifically the pancreas. The human body requires blood glucose, that is blood sugar, to be present in the blood in a narrow range. Glucagon and insulin are the hormones that play the role in here. Both these hormones are secreted from the pancreas. This is the reason why they are referred to as the pancreatic endocrine hormones. The hormones are secreted by the islet cells of the pancreas. The production of the glucagon and insulin determines whether the patient has hypoglycaemia, diabetes or other problems. The insulin stimulus results in high blood glucose and glucagon stimulus results in low blood glucose (Haidar et al., 2013).
The effects of hormone imbalance, using underactive thyroid as an example
Hormones are the chemical substances in the body that affect the brain, muscles, heart, bones and reproductive organs. These are essential for body functioning. However, in some cases, there may be an imbalance of the hormone level in the body. The common reasons for hormone imbalance are improper functioning of the hormone secreting gland, higher level of stress, sedentary lifestyle, improper diet and deficit of sleep (Pearce, 2015). Several problems are associated with hormone imbalance. One example is the underactive thyroid gland. The medical term is hypothyroidism. Hypothyroidism, or underactive thyroid gland is a common hormonal disturbance. The thyroid hormone, secreted by the thyroid gland, regulates energy usage in tissues in the body. In cases of hypothyroidism, patients have some level of fatigue, have a tendency to feel more cold, experience more weight gain. Sleepiness in daytime is common (Komatsu et al., 2016).
Comparison between the nervous system and endocrine system
There are some basic differences between the nerves and the hormones, that are the primary components of the nervous system and the endocrine system respectively. The nerves are made up of neurone that contains a cell with a nucleus and cytoplasm that extends to produce the dendron. The dendron has long structures called dendrites. They have the role of stimulating electrical impulse from surrounding neurones. For hormones, three kinds of structure are found. Hormones may be fat-soluble molecules, amino-acid derivatives or water-soluble polypeptides (Melander et al., 2013).
The endocrine system and the nervous system are two different systems. Nevertheless, they are complementary systems and they work together for helping the body to function properly. On the general basis, responses made by the endocrine system are slower than the nervous system and thus the control processes may be slow. The nervous system has a rapid response to the stimuli by the method of sending electrical action potentials in neurons. The response is instantaneous. The functioning of the endocrine system depends on hormones to obtain responses from the target cells. When the hormones reaches the target cell they act on the cell for increasing or decreasing the gene expression. This process takes longer time than that of the nervous system. Faster body functions are taken up by the nervous system. For example, the endocrine system influences body functions like cell growth. On the other hand, the faster processes in the body, like breathing, have the control by the nervous system (McCann, 2013).
References
Haidar, A., Legault, L., Dallaire, M., Alkhateeb, A., Coriati, A., & Messier, V. et al. (2013). Glucose-responsive insulin and glucagon delivery (dual-hormone artificial pancreas) in adults with type 1 diabetes: a randomized crossover controlled trial. Canadian Medical Association Journal, 185(4), 297-305. http://dx.doi.org/10.1503/cmaj.121265
Komatsu, R., You, J., Mascha, E. J., Sessler, D. I., Kasuya, Y., & Turan, A. (2016). The Effect of Hypothyroidism on a Composite of Mortality, Cardiovascular and Wound Complications After Noncardiac Surgery: A Retrospective Cohort Analysis. Survey of Anesthesiology, 60(1), 34-35.
McCann, S. M. (Ed.). (2013). Endocrinology: people and ideas. Springer.
Melander, A., Ericson, L. E., & Sundler, F. (2013). Sympathetic regulation of thyroid hormone secretion. Minireviews of the Neurosciences from Life Sciences, 14, 163.
Melmed, S., Polonsky, K. S., Larsen, P. R., & Kronenberg, H. M. (2015).Williams textbook of endocrinology. Elsevier Health Sciences.
Nussey, S. S., & Whitehead, S. A. (2013). Endocrinology: an integrated approach. CRC Press.
Pearce, E. N. (2015). The Presence of Hypothyroid Symptoms Is More Reliable in Diagnosing Hypothyroidism in Men Than in Women. Clinical Thyroidology, 27(6), 152-154.
Strauss III, J. F., & Barbieri, R. L. (2013). Yen & Jaffe’s Reproductive Endocrinology: Physiology, Pathophysiology, and Clinical Management. Elsevier Health Sciences.
Zarrow, M. X. (2012). Experimental endocrinology: a sourcebook of basic techniques. Elsevier.
