- If the thyroid gland were removed from a cancer patient, would you expect the level of TSH to rise or fall? Why?
Malignancies of the head and neck include those of the oral cavity, oropharynx, hypopharynx, nasopharynx, nasal cavity, paranasal sinus and larynx. These cancers account for fewer than 5% of all cancers. Depending on the location and stage, treatment may consist of radiation therapy, chemotherapy, surgery, or a combination of these modalities. The secretion of T3 and T4 by the thyroid gland is controlled by the thyroid stimulating hormone or TSH.
TSH controls the rate of thyroid hormone release.
In turn the level of thyroid hormone in the blood determines the release of TSH. If the thyroid gland were removed from cancer patient, the level of TSH would fall. It is because thyroid glands secretes hormone T3 and T4, so if the thyroid gland will be removed there is a possibility that the TSH that controls these two hormones will fall down, decrease or deteriorate.
The primary function of the thyroid hormone is to control the cellular metabolic activity. T4, a relatively weak hormone, maintains body metabolism in a steady state. T3 is about five times as potent as T4 and has a more rapid metabolic action. This hormone accelerates metabolic processes by increasing the level of specific enzymes that contribute to oxygen consumption and altering the responsiveness of tissues to other hormones. The thyroid hormones, through their widespread effects on cellular metabolism, influence every major organ system.
- Which could a person more easily live without-the adrenal medulla or adrenal cortex?Why?
The adrenal medulla functions as part of the autonomic nervous system. A person can easily live without the adrenal medulla. Stimulation of preganglionic sympathetic nerve fibers, which travel distinctly to the cells of the adrenal medulla. Causes release of the catecholamine hormones epinephrine and norepinephrine. About 90% of the secretion of the human adrenal medulla is epinephrine.
- Catecholamines regulate metabolic pathways to promote catabolism of stored fuels to meet caloric needs from endogenous sources. The major effects of epinephrine release are to prepare to meet a challenge which is the flight or fight response. Not like the adrenal cortex which is necessary for life, for adrenocortical secretions make it possible for the body to adapt to stress of all kinds. Without adrenal cortex, severe stress would cause peripheral circulatory failure, circulatory shock, and prostration.
3. A person with toxic goiter tends to sweat profusely. Explain this in terms of homeostasis.
Individuals with toxic goiter tolerate heat so poorly and perspire unusually freely.
Human being as a separate from the external environment and constantly endeavoring to maintain physiologic equilibrium, or balance, through adaptation to that environment. Homeostasis, then, is the tendency of the body to maintain a state of balance or equilibrium while continually changing. The homeostatic mechanisms have four characteristics: they are self-regulating, they are compensatory, they tend to be regulated by negative feedback systems, they may require several feedback mechanisms to correct and they may require several feedback mechanisms to correct only one physiologic imbalance.
In good health, a delicate balance of fluids, electrolytes, and acids and bases is maintained in the body. This balance, or physiologic homeostasis, depends on multiple physiologic processes that regulate fluid intake and output and the movement of water and the substances dissolved in it between the body compartments. Almost every little illness has the potential to threaten this balance.
Even in daily living, excessive temperatures or vigorous activities can disturb the balance if adequate water and salt intake is not maintained. The volume and composition of body fluids is regulated through several homeostatic mechanisms. A number of body systems contribute to this regulation, including the kidneys, the endocrine system, the cardiovascular system, the lungs, and the gastrointestinal system.
- Allender, J. A., & Spradley, B. W. (2000). Community health nursing: Concepts and practice (5th Ed.). Philadelphia: Lippincott Williams and Wilkins.