Respond to peers using the lessons and vocabulary found in the readings. Support your answers with examples and research. Your responses should clarify your understanding of the topic. They should be your own, original, and free from plagiarism. Follow APA format for writing style, spelling and grammar, and citation of sources.

Peer #1:

Explain the connection between T3 and T4 and infertility, gynecomastia, etc.

Peer #2 Ana

1. Explain the action of thyroid hormone and how this impacts the diagnosis. Your answer should contain the impact of the thyroid hormone on functions in the body.

Thyroid hormone refers to a group of hormones produced by the thyroid gland of the endocrine system. The thyroid gland is located around the throat on the neck of the human body. The thyroid gland produces three distinct hormones, which are collectively referred to as the thyroid hormone. These hormones include; Triiodothyronine (T3), tetraiodothyronine (T4), referred to as thyroxine, and calcitonin. The most known thyroid hormone is thyroxine (T4), and triiodothyronine, as they play major roles in maintaining general body functions. The roles played by calcitonin are mostly overlooked as it plays a small role in obtaining calcium balance in the human body (Sinha et al., 2018). The hormones play a major role in maintaining general body metabolism, contributing to the body organs’ growth, and increasing body development. High secretion of thyroid hormones leads to an increase in the rate of body cell metabolism. At the same time, the decrease in its production decreases the rate of cell metabolism.

The thyroid hormone production is stimulated by the thyroid-stimulating hormone that acts on the anterior pituitary gland. Increased thyroid-stimulating hormone levels lead to increased T4 and T3 hormone secretion from the thyroid gland. After the thyroid gland secretes the thyroid hormones, they are transported through the blood to the body cells. The hormones enter the body cell by utilizing the cell membrane transporters (Hoermann et al., 2017). In the cell nucleus, the hormone receptor in the cell nucleus binds with the specific hormone receptors. In the cell nucleus, the hormone is able to produce its inhibitory properties that affect gene expression.

The hormone has different effects on the diagnosis, whereby its overproduction leads to hyperthyroidism. The disease can be caused by the increased intake of the iodine mineral mostly contained in the iodized salts (Søgaard et al., 2016). A high number of autoantibodies in the body also triggers the thyroid hormone’s increased production by acting on the thyroid-stimulating hormone.

Low secretion of the thyroid hormone mostly associated with the low level of iodine in the body leads to a disease condition referred to as hypothyroidism. The most commonly known symptom of this disease condition is the overgrowth of the thyroid gland due to its stress, straining to produce more hormones to meet the body requirements.

1. As Thyroid Stimulation Hormone (TSH) levels rise, explain how this impacts the negative-feedback mechanism in the body.

The thyroid hormone production by the thyroid gland is regulated by the thyroid-stimulating hormone that acts on the anterior pituitary gland. The thyroid-stimulating hormone is a glycoprotein that is secreted by thyrotrope cells found in the endocrine system. The increased production of the thyroid-stimulating hormone leads to the overstimulation of the anterior pituitary gland, increasing the production of thyroid hormones. The increased production of the thyroid hormones leads to high production of the T3 and T4 hormones. High production of thyroid hormones leads to the activation of negative feedback. The initiated negative feedback mechanism is to reduce the thyroid gland’s rate to produce the thyroid hormones. When the secretion of the thyroid hormones decreases beyond a certain limit, it inhibits the negative feedback initiation, the thyroid-stimulating hormone levels in the pituitary gland remain high.

The maintenance of the thyroid-stimulating hormone at a higher level leads to the decreased production of the T3 and T4 hormones, and hence the body metabolism remains abnormally low. The low level of thyroid hormones in the body triggered by the high levels of the thyroid-stimulating hormone leads to a condition referred to as hypothyroidism. This condition is associated with various signs and symptoms, including excessive coldness, getting tired quickly, sluggish feeling, and weight gain. These signs and symptoms of hypothyroidism are due to decreased cell metabolic processes (Søgaard et al., 2016). Hypothyroidism leads to the emergence of signs and symptoms like fertility loss and the high risks of succumbing to heart disease. The patients often experience strenuous breathing difficulties, dry skin, and soft inflamed face. The disease progresses with time ranging from mild to severe. The signs and symptoms are also varied depending on the phase of the disease condition.

1. What are the roles of Thyroxine (T4) and triiodothyronine (T3) in the body?

The thyroid gland produces two major hormones, namely thyroxine (T4) and triiodothyronine. Thyroxine (T4) makes the highest percentage of the thyroid hormone, with the triiodothyronine playing a role in making thyroxine through the di-iodization process. The function of these hormones in the human body is mainly regulating the metabolic processes of the cells. The hormones play a major role in the increased growth of the human body’s long bones through their collaboration with the growth hormones (Bassett & Williams, 2016). The activities of the thyroid hormones also support the differentiation of the body cells. The increased ability to control cell metabolism is attributed to the hormones’ unique ability to control the synthesis of proteins, carbohydrates, vitamins, and fats (Costa-Pinto & Gantner, 2020). The hormone responds to various body functioning changes, which is mostly affected by the body’s psychological state, including the changes in the physiological state. The iodine mineral highly controls the thyroid gland by increasing the gland’s resistance to the thyroid-stimulating hormone.

References

Bassett, J. D., & Williams, G. R. (2016). Role of thyroid hormones in skeletal development and bone maintenance. Endocrine reviews, 37(2), 135-187.

Costa-Pinto, R., & Gantner, D. (2020). Macronutrients, minerals, vitamins and energy. Anaesthesia & Intensive Care Medicine, 21(3), 157-161.

Hoermann, R., Midgley, J. E., Larisch, R., & Dietrich, J. W. (2017). Recent advances in thyroid hormone regulation: toward a new paradigm for optimal diagnosis and treatment. Frontiers in endocrinology, 8, 364.

Sinha, R. A., Singh, B. K., & Yen, P. M. (2018). Direct effects of thyroid hormones on hepatic lipid metabolism. Nature Reviews Endocrinology, 14(5), 259.

Søgaard, M., Farkas, D. K., Ehrenstein, V., Jørgensen, J. O., Dekkers, O. M., & Sørensen, H. T. (2016). Hypothyroidism and hyperthyroidism and breast cancer risk: a nationwide cohort study. European journal of endocrinology, 174(4), 409.

Peer#3

Kimberly

1. Explain the action of thyroid hormone and how this impacts the diagnosis. Your answer should contain the impact of the thyroid hormone on functions in the body.

• Hypothyroidism is a result from the deficient production of the thyroid hormone by the thyroid gland. When the thyroid function is lost, it leads to a decrease in the production of the thyroid hormones (T3 and T4) and an increase secretion of TSH and TRH (Heather & McCance, 2019). Throughout the body, the thyroid hormone has a major effect on maturation, growth, and function of cells throughout the body. They bind to receptors in the plasma membrane, mitochondria, or cytoplasm and generate membrane-initiated signaling effects (Heather & McCance, 2019).
• There are also permissive effects that the thyroid hormone has throughout the body, where the actions of neurotransmitters and actions of other hormones are optimized. The patient has a heart rate of 58 BPM, in hypothyroidism there is a reduction in stroke volume and heart rate causing a lower cardiac output. This results from the decrease in metabolic demands and loss of regulatory and rate-setting effects of TH (Heather & McCance, 2019). Her pale, cool, dry, and thick skin is caused by reduced sweat and sebaceous gland secretion. She also voiced that she’s been having neurological issues such as loss of memory and slow speech. With hypothyroidism, the neurologic system is affected by decreased cerebral blood flow leading to cerebral hypoxia and the intracellular processes are reduced caused by a decrease in ?-adrenergic activity related to the decrease in the number of ?-adrenergic receptor sites (Heather & McCance, 2019).

1. As Thyroid Stimulating Hormones (TSH) rise, explain how this impacts the negative feedback mechanism in the body.

• The HPA (hypothalamic-pituitary axis) functions to regulate the secretion of the thyroid hormones using feedback loops. The hypothalamus secretes the TRH or thyroid-regulating hormone and it stimulates the adenohypophysis to secrete TSH (Pirahanchi et al, 2020). The thyroid gland’s epithelial cells possess specific receptors for TSH. Once they are bonded, it stimulates the secretion of T4 and T3 which affects all body cells. The negative feedback occurs when the levels of thyroid hormones elevate above the threshold. It inhibits the secretion of TRH that further turn off the secretion of TS, as a result the levels of thyroid hormones fall. If the secretion rate of the thyroid hormones increases, the adenohypophysis decreases the secretion of TSH through negative feedback (Pirahanchi et al, 2020). If the rate decreases, as in hypothyroidism, the negative feedback does not operate and as a result, the adenohypophysis increases the secretion of TSH.

1. What are the roles of Thyroxine (T4) and triiodothyronine (T3) in the body?

The roles of Thyroxine and triiodothyronine includes:

• Regulating the catabolism of protein, fat, and carbohydrate in all cells as well as regulating the metabolic rate in all cells
• Maintains growth hormone secretion and skeletal maturation
• Affects the development of the central nervous system
• Maintains cardiac rate, force, and output
• Affects respiratory rate and oxygen utilization
• Stimulates lipid turnover, free fatty acid release, and cholesterol synthesis (Heather & McCance, 2019).

Reference

Heather, S., McCance K. (2019). Pathophysiology the Biologic Basis for Disease in Adults and

Children. (8^th ed). St. Louis, MI. Elsevier

Pirahanchi, Y., Toro, F., Jialal I (2020). Physiology, Thyroid stimulating hormone (TSH).

StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK499850/